The OPAL Higgs group
pr329.tex
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%  Title :   Search for Standard Model Higgs Boson at $\sqrts=192--209$ GeV
%  Authors:  The OPAL Higgs group
%  Editors:  Satoru Yamashita + Pauline Gagnon + Tom Junk
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Modification Log: 
%
% 9 Jan 01 Tom PR329 + comments (minor) from referees.
%21-Dec-00 Tom    V +4.2.2 Nearly final -- some comments after the final dispatch
%19-Dec-00 Tom    V +4.2.1 Move dedication up to front page (Stefan and PeterM) -- where it
%                        ends up in the journal is a good question.
%18-Dec-00 Tom    V +4.1 Add author list and acknowledgements
%18-Dec-00 Tom    V +4.0 After EB comments after Public reading
%13-Dec-00 Tom    V +2.5.1 some small text changes
%13-Dec-00 Satoru V +2.5 Figures refinement.
%13-Dec-00 Tom    V +2.4 Updated fig5(a) made. And nice fig6 as well. 
%13-Dec-00 Satoru V +2.4 Updated fig5(b) made. Fig caption changed.
%13-Dec-00 Satoru V +2.4 small modification.
%12-Dec-00 Satoru V +2.3 put refined fig.4(a)
%12-Dec-00 Satoru V +2.3 small correction. Reference ordering etc..
%12-Dec-00 Satoru V +2.2 Ordering of paragraph re-changed in Sec.3.2 to
%                   be the same as dispatch version.
%12-Dec-00 Satoru V +2.2 delete unused CL values explanation. Length is OK. 
%12-Dec-00 Satoru V +2.2 Let's go to Sec.3.2... Try to further shorten. 
%12-Dec-00 Satoru V +2.1 Adding new information suggested to put in PR, 
%       length is kept unchanged for Sec2, 3, 3.1.  Sec.3.2 is too lo----ng.
%12-Dec-00 Satoru V +2.1 further more shorter Sec.3. and 3.1. 
%12-Dec-00 Satoru V +2.0 shorter Sec.3. and 3.1. 
%12-Dec-00 Satoru -- Version up +2.0 still too long. much longer than dispatch.
%12-Dec-00 Satoru -- shorten CLs+b definition.
%12-Dec-00 Satoru -- shorten D_mass etc..
%12-Dec-00 Satoru -- decide to shorten systematic error part first.
%12-Dec-00 Satoru -- TOO LONG!!! While we had Giorgio's comment, now it's longer!!!!
%12-Dec-00 Satoru -- fig.1,2,3,4(b)(c) and tab.1 updated along public reading.
%12-Dec-00 Satoru -- Numbers in systematic error paragraph corrected.
%11-Dec-00 Satoru -- Sec.3.2 Q explanation a bit shorten. Put Ecm bin as well.
%11-Dec-00 Satoru -- Put a remark mass dist is not enough in Sec.3.1.
%                    and guide to Sec.3.2 to get real sensitivity.
%11-Dec-00 Satoru -- Text and numbers in Sec.3.1 changed.
%11-Dec-00 Satoru -- Follow public reading. Remove tab.2. Insert new tab.1.
% 9-Dec-00   Tom -- Updated with fixed e and muon channel candidates
% 8-9-Dec-00 Tom -- Comments from the public reading
% 5-Dec-00   Tom -- added acknowledgements.  Cited Glashow, 
%       add a reference for +-2% 4f xs uncertainty
% 4-Dec-00 Pauline Made minor text changes following Rob, Graham and Pippa
%          comments after the dispatch - all in comments.txt
%
% 1-Dec-00 Satoru V 1.00: Final checks for the first dispatch.
%             Comment deadline move by one day to get one week for comment.
%             Sec.3 "The small variations are due to Monte Carlo statistics
%                    and background shape in the four-jet channel."
%                 ==> "The small variations are mostly due to Monte Carlo 
%                     statistics."
%             Sec.3 move the explanation of ln(1+s/b) for Fig7 to upper part 
%                  for Fig.6
%
% 1-Dec-00 Pauline: changed date, deadline for comments and font
%   and replaced "Submitted to PRL " by "To be submitted to PRL"
% and called that the first dispatch
% changes to changes made by Satoru:
%We therefore consider this mass hypothesis in most detail here.
%We therefore consider this mass hypothesis in greater detail here.
%
% The expected resolution on (instead of "of") the
%reconstructed mass for a Higgs boson with 105 GeV mass is 
%
% 1-DEc-00 Pauline: comments received by Gail implemented.
%   p. 2, line 13: a kinematic fits -> kinematic fits
%   
%   p. 2, last paragraph, 5th line: B hadron -> b-hadron
%   
%   Section 2.1, 3rd paragraph, 5th line: remove the comma after "channel"
%   
%   Section 2.1, 4th paragraph, last line: are an estimate of the systematic
%   uncertainties -> include the systematic uncertainties
%   
%   Section 2.2, 4th paragraph, 6th line: Figure -> Figures
%   
%   Section 2.2, 4th paragraph, last line: for discriminant -> for the
%   discriminant
%   
%   Section 3, 1st paragraph, 4th line: put a comma after "107 GeV"
%   
%   Section 3, 1st paragraph, last line: Put the footnote 1 on a word, not a
%   symbol - either "corresponds" or "approximately"
%   
%   Section 3, 2nd paragraph, 6th line: for the Standard Model Higgs
%   production -> for Standrad Model Higgs production
%   
%   Section 3, 3rd paragraph, 1st line: "highest" -> "largest"
%   
%   Figure 6 should be introduced somewhere. I would put the words at the
%   beginning of the third paragraph since it shows all the candidates, not
%   just the most significant. Suggestion: "Figure 6 shows the ln(1 + s/b)
%   distributions as a function of the Higgs boson mass for each of the
%   candidates collected in 2000. [Put something about the bumps here.]"
%   
%   Section 3, 4th paragraph, 1st line: The candidate -> Candidate
%   
%   Section 3, 6th paragraph, 1st line: log -> logarithm
%   
%   Section 3, last paragraph, lines 8-9: 2sigma -> +/- 2sigma
%        range -> ranges
%   
%   References [3] (two places) and [14]: accepted by -> to be published in
%   
%   Figure 1 caption: the subscript Z should not have the superscript zero
%   
%   Figure 2 caption: dotted -> dashed [it looks dashed to me!]
%   
%   Figure 4 caption, 1st line: discriminator -> discriminant
%        2nd and 3rd lines: after "(points)," change to "the Monte Carlo
%   expectation for the q qbar (gamma) (dark-shaded) and four-fermion
%   (light-shaded) backgrounds, and a 115 GeV Higgs ...."
%   
%   Table 3: I still think it would look better wider - then you could put
%   "Missing-Energy" instead of "Missing-E" for example
%   
%        column two heading: channel -> Channel
%   
%   Table 3 caption [you missed some of my earlier corrections]:
%        1st line: highest -> largest
%        2nd line: The mHrec is -> The column labeled "mHrec" lists
%        2nd line: The L^{HZ} column is -> The column labeled "L^{HZ}" shows
%        3rd line: are for -> give
%        4th line: discriminators -> discriminants
%        7th line: highest -> largest
%   
%   Figure 6 caption, 1st line: distribution -> distributions
%        4th line: of each candidate -> for each candidate
%   
%   Figure 8: the dashes should be longer - they look like dots
%   
%   Figure 8 caption, last line: the Standard Model Higgs boson of 115 GeV ->
%    a Standard Model Higgs boson of mass 115 GeV [note: two changes]
%        Remove "See the text."
%   
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
% 1-Dec-00 Satoru V 0.97:
%    Done for Klaus and Eric's comment sent at late night.
% 1-Dec-00 Satoru V 0.96:
%    Done for Dave's comment sent 23:16 GMT.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
%30-Nov-00 Satoru V 0.95: 
%
%   o Fig2,3,4(b) further modification as requested.
%   o Fig4(a) better version from Fredrik.
%   o Fig.6(d) Lepton Channels ---> Electron and Muon Channels
%   o Fig.7 and 8 caption $ln$ corrected to \ln
%   o Reference [3] L3 EP preprint number in.
%   o DELPHI reference deleted, and no citation for it in the text.
%     (p.1 6th line) No citation for [3,4].
%   o In Sec.3, 4th para, 5th line. "This means ..." deleted.
%     Sec.3, 4th para, 3rd line, the sentence "In addition, the resolution
%     of the..." is revised to 
%     "The expected resolution of the reconstructed mass for a Higgs boson 
%      with 105 GeV mass is $\sim$3~GeV, 
%      and approximately 6 GeV for a 115 GeV mass 
%      with a long tail towards lower reconstructed masses."
%   o p2. 3rd line "The uncertainty in ...."
%  ===>
%    "Also additional
%     uncertainties in the background 
%     are estimated by comparing Monte Carlo samples
%     generated with different generators~\cite{CEEX,pythia,grc4f,koralW}."
%
%30-Nov-00 Satoru  V 0.9: at 19:00 hour, distribute to EB members.
%30-Nov-00 Satoru  V 0.9: 
%              Fig.1,2,3,4,5 modification following Eric's suggestions 
%
%30-Nov-00 Pauline V 0.8: 
%              Almost all Klaus, Gail, Eric's comment to text/captions
%
%30-Nov-00 Pauline V 0.7: Almost all Dave's comments for fig/tab captions. 
%30-Nov-00 Satoru  V 0.7: Almost all Dave's comments for text. 
%
%30-Nov-00 Satoru  V 0.6: Dave's comment from #11 to #31 done.
%                         Checked #5,6b and corrected.
%30-Nov-00 Pauline V 0.5: Dave's comment #1 to #10 done
%
%29-Nov-00 Pauline V 0.0:
% added a few things mentioned at EB not yet done by Satoru 
% revised section 2.2 on CL calculation and description of s/b
% revised event description with many jet-pairing for candidate #1
% not done but requested by Eric: move ref. to figure 6 earlier
%  --> it simply does not fit...
% added luminosity for Z0 calibration
%
%  to be checked: limit (updated value is 108.4 GeV / 112.7 GeV exp)
%                 6*10^-3 for lowest 1-CLb at 107 GeV.   -- how much sigma?
%                 Summary table signal count
%  to be updated:
%  done           115 GeV motivation in introduction!
%                 Description of -2lnQ definition.
%  done           Reference Updated W boson x-section paper to eb ref. to.
%               
%28-Nov-00 Satoru V -1.0 CL results numbers (updated ones) in bold for now.
%
%28-Nov-00 Satoru V -1.0 Fig.6,7 updated by Tom.
%                back to dotted line for Fig.6.
%28-Nov-00 Satoru V -1.0 Reference
%                Delete GIM reference from SM reference.
%                Delete MC title.
%                Delete LEP Energy WG
%                Delete "to be submitted to NIM" from P.Bock reference
%
%28-Nov-00 Satoru V -1.0 Sec.4 
%                delete "The results have been...calibration."
%                Numbers are updated.
%                "between 105 and 110 GeV" --> at 107 GeV
%                change sentence "The largest deviation..."
%                change the ordering of limit and excess at 107 GeV.
%28-Nov-00 Satoru V -1.0 Fig.7 caption 105 --> 107 GeV.
%28-Nov-00 Satoru V -1.0 remove extra additional figure, text.
%28-Nov-00 Satoru V -1.0 Fig.6 caption   Dotted line --> dashed line.
%27-Nov-00 Satoru V -1.0
%   Fig5 (a) (b) updated. Take Peter Bock's new figures, and mod in eps fig.
%   -- delete preliminary. 
%   -- make 1,2,3 sigma lines and delete hatches for 1-CLb.
%28-Nov-00 Satoru V -1.0 Fig.4 typo corrected.
%28-Nov-00 Satoru V -1.0 Sec.3 
%           delete line "To calculate the CL, a weight is..."
%         candidate description stick only to several important information
%         and relation between excess at 107 GeV.
%           Cand #1 description a bit changed.
%           Cand #2 description shorten.
%           Cand #3 description shorten.
%           Cand #4 description removed. --- not significant event
%         Sentence "The minimum in the left-hand plot is near \mH=109~GeV,.."
%         is no longer true. Change the sentence.
%28-Nov-00 Satoru V -1.0 Tab.3 caption "significant" --> highest...
%                              Emis cand #4 mass 112.2 --> 112.1 GeV (CU)
%
%28-Nov-00 Satoru V -1.0 Sec.2.2
%  Try a better explanation of CL calculation (p6 2nd para 2nd-3rd line).
%    Now explain it with number of events in bin, instead of "local density".
%  move sentence "These four variables are ... using a likelihood technique."
%    to the starting point of Dmass explanation.
%  Energy uncertainty description modified as Eric's suggestion.
%28-Nov-00 Satoru V -1.0 Tab.1 caption h^0--> H^0
%28-Nov-00 Satoru V -1.0 HZ 5C-fit --> H^0Z^0 5C-fit
%28-Nov-00 Satoru V -1.0 Fig.2 caption in italic.
%28-Nov-00 Satoru V -1.0 Fig.1
%          lnqq --> qqln in caption and fig (d)
%28-Nov-00 Satoru V -1.0 Sec.2.1
%          lnqq --> qqln
%          p5 end of 1st para, add a sentence for the err for bkg expectation.

%28-Nov-00 Satoru V -1.0 Sec.2
%   Add "in each analysis channel" for 2nd line.
%   Delete ", each channel requiring different subdetectors to be operational."
%   Add 1999 and 2000 data sqrt(s) range and lumi-weight Ecm.
%   Delete "The hadron beamspot size in ... event-by-event."
%   multihadronic --> hadronic 
%   p.3 4th line high energy data --> data taken at sqrt(s)>192 GeV
%   p.3 s' near Z ---> the mass of the qq system
%   p.3 last of 2nd para "mismodelling of the light-flavour tag rate"
%          -----> mismodelling of the tagging rate
%   
%   What to do: Z-pole lumi to be mentioned?
%   
%28-Nov-00 Satoru V -1.0
%   Introduction: (motivation of this letter (115 GeV) to be made later!)
%      delete "This adds little... process.
%28-Nov-00 Satoru V -1.0
%   Abstruct: Delete line 3--4 "We search for... and tau tau".
%             Delete 8th line "but is inconsistent...."
%             Replace 8*10^-3 --> 6*10^-3, 2.6 sigma ---> 2.X sigma.
%             105--110 GeV --> 107 GeV.
%             1-CLb 0.2 at 115 GeV --> 0.15. 1.2 sigma --> 1.X sigma
%             
%27-Nov-00 Satoru V -1.0
%   Updated results from Peter Bock!!
%   Read values are   108.4 GeV obs limit / 112.7 GeV for expectation.
%                     1-CLb minimum = 0.006 at 107 GeV ==> changed to 0.01
%                     1-CLb =~ 0.15 at 114--116 GeV    ==> changed to 0.2
%
%27-Nov-00 Pauline V -1.1
% - rename figures in the right order
% - implement latest text corrections from Gail
% - add suggested other changes from Gail - still commented out
%   search for "Gail" as a key word to see them
% - add two figures: -2lnQ for 105 and 115 GeV and event display
%
%26-Nov-00 Pauline V -1.2
% - Implemented small text corrections from Gail from version -1.6
%   including rephrasing in caption fig 7. The bin-to-bin correlation
%   phrase applies to the integral part.
% - Re-ordering of the references
% - small rephrasing in intro on the MC generators
% - changed total int. lumi. of 423 in abstract and intro for 426 for consistency
%   with details given in section 2
% - remove 2nd sentence about g --> bb to avoid repetition (end of section 2)
% - caption fig. 3 slightly modified: tau channels (plural)
% - tau channels (plural) also at end of one before last par. in section 2.2
% - "test mass" is defined earlier, when first mentioned
% - last par. in section 2.2: replace "as well as" by "or" for list 
%   of correlated errors
% - same par: "is neglected" was repeated twice. Replaced by "Both are neglected."
% - move par. explaining fig. 5b after the par. explaining 5a.
% - added definition of weight and s/b (requested by Gail) and moved to par 3
%   of section 3.
% - updated [ref 3] and cleaned typos etc. in references
% - replaced preprint refe. for CEEX by published PRL ref.
% - references that need to be updated/finalised are in boldface
%
%24-Nov-00 Satoru V -1.3
%   Further re-structuring.
%
%24-Nov-00 Satoru V -1.4
%                 Re-structuring the draft along EB members' suggestion.
%   Global structure: 
%      1. move CL calculation "procedure" into Sec 2.
%      2. move all CL input related things to CL calc procedure Sec.
%     So now Sec.2 is
%         Intro. 
%         o Sec.2.1 b-tag.
%         o Sec.2.2 Selection.
%         o Sec.2.3 CL calculation procedure.
%         o Sec.2.4 Systematic error
%         
%
%24-Nov-00 Satoru V -1.4 clean up.
%24-Nov-00 Satoru V -1.4 Tab.3 caption 0.25 --> 0.2.
%
%24-Nov-00 Satoru V -1.5 DISTRIBUTED
%24-Nov-00 Satoru V -1.5 text total Y2K error values updated.
%24-Nov-00 Satoru V -1.5 tab.2 error values updated.
%24-Nov-00 Satoru V -1.5 tab.1 error values updated.
%24-Nov-00 Satoru V -1.5 tab.3 weight final update (sent from Tom).
%24-Nov-00 Satoru V -1.5 Text delete for "For the 2000 data, events with 
%                       a jet-pairings.." in p4.bottom along Dave's suggestion.
%24-Nov-00 Satoru V -1.5 gluon splitting reference in.
%24-Nov-00 Satoru V -1.5
%          Fig.2 signal separated along Dave's suggestion. 
%          Dotted line. Use 115 GeV instead of 110 GeV.
%          Change in figure caption.
%24-Nov-00 Satoru V -1.5 Fig.2,3,4(bc) are updated with final data/MC.
%24-Nov-00 Satoru V -1.5
%          Tau CU updated. Now all channels are final.  159-->160 in precut.
%          Tau bkg systematic errors updated.
%24-Nov-00 Satoru V -1.5
%          gluon-->bb cc etc, b-->g + b etc reweighting results in.  
%23-Nov-00 Satoru V -1.5 - figure1 reference in text changed from(a-e)to(a-d).
%23-Nov-00 Satoru V -1.5 - figure1 caption updated
%23-Nov-00 Satoru V -1.5 - updated figure1 in. Follow Dave/Klaus's suggestions.
%
%17-Nov-00 Satoru V -1.6 - simple update for numbers; 
%    o Final eff Ecm interpolated for 4j. 
%    o CU process over for Emis. Check out over. Final data count is obtained.
%      --> Tab.2 Emis data count updated (final). 4j Signal eff final.
%      --> summary tab Tab.3 Emis data update. Total counts updates. 4j update
%      --> Data count 74-->75 in text.
%      --> full cut flow update for Emis precuts and final.
%17-Nov-00 Pauline V-1.7 - incorporating some comments from 
%     Giorgio, Dave and Klaus
%      - remove fig 1 and table 1 -> syst. 
%          errors added on signal in table 2 (now 1)
%      - new introduction from Stefan and Rob slightly modified with 
%          comments received
%      - removed text on mini-ramps
%      - intermediate step added in figure 2 between presel and L cut.
%      - some internal reshuffling of figures and tables.
%16-Nov-00 Satoru V -1.8 Tab.1, 2, 3 intermediate update. 
%      Total count 71-->74. Exp 62.7+-6.5-->67.4+-5.2 in text.
%      fig.2, 3, 4, 5(b,c) updated. --- Isamu 
%      fig.5(a) updated. --- Fredrik
%      put "just-for-eb-process" tables after \end{document}
%16-Nov-00 Pauline V-1.9 Tab. caption modification.
%16-Nov-00 Pauline V-1.9 Fig. caption modification.
%16-Nov-00 Pauline V-1.9 Ref modification.
%16-Nov-00 Pauline V-1.9 Text modification many places.
%15-Nov-00 Satoru V -2.0 Now it's time to distribute and send to Pauline.
%15-Nov-00 Satoru V -2.1 Save and check it again.
%15-Nov-00 Satoru V -2.1 tune up.
%15-Nov-00 Satoru V -2.2 Clean up
%15-Nov-00 Satoru V -2.3 Now 21pages --> 19pages.
%15-Nov-00 Satoru V -2.3 Sec.2 bit shorter.
%15-Nov-00 Satoru V -2.3 Delete unnecessary references.
%15-Nov-00 Satoru V -2.3 Emis channel preselection list deleted.
%                        simply say what was changed.
%15-Nov-00 Satoru V -2.3 Abstract/conclusion delete last sentence.
%15-Nov-00 Satoru V -2.3 Introduction --- delete all LEP comb related things 
%15-Nov-00 Satoru V -2.3 Gather all channel selection in one subsection.
%15-Nov-00 Satoru V -2.3 Event selection for lepton/tau deleted.
%15-Nov-00 Satoru V -2.3 Event selection for 4jet mostly deleted.
%15-Nov-00 Satoru V -2.3 Sys error section add several sentences.
%15-Nov-00 Satoru V -2.3 Tab.1 delete several items.
%15-Nov-00 Satoru V -2.3 Trial plot for Fig.5 in (Isamu made it).
%15-Nov-00 Satoru V -2.3 Table.2 omit pre-preselection. 
%                        Now only before/after LH selection.
%                        Keep full cut-flow in ONLY-FOR-EB-PROCESS part at end.
%15-Nov-00 Satoru V -2.3 Modification. Shorten several fig captions.
%15-Nov-00 Satoru V -2.3 arrange fig name to give it to next editors
%14-Nov-00 Satoru V -2.4 Distribute
%14-Nov-00 Satoru V -2.4 Now 21 page... Anyway check...
%14-Nov-00 Satoru V -2.5 Tuning again...
%14-Nov-00 Satoru V -2.6 Now 23 pages. Better...
%14-Nov-00 Satoru V -2.7 Try try try...
%14-Nov-00 Satoru V -2.8 Still 24 pages.... Try to make it shorter...
%14-Nov-00 Satoru V -2.9 Further modification, shortening.
%14-Nov-00 Satoru V -3.0 Further shortening.
%14-Nov-00 Satoru V -4.0 SHORT (letter) version
%14-Nov-00 Satoru V -5.0 clean up
%14-Nov-00 Satoru V -6.0 Many changes/corrections
%14-Nov-00 Satoru V -6.0 Lumi plot
%13-Nov-00 Satoru V -7.0 many many changes.
%13-Nov-00 Satoru V -8.0 many many changes.
%12-Nov-00 Satoru V -9.0 many changes
%11-Nov-00 Satoru V -9.0 B-tag figures in.
%11-Nov-00 Satoru V -9.0 Make structure better.
%10-Nov-00 Satoru V-10.0 Make first structure
%10-Nov-00 Satoru V-10.0 patch-works.
%10-Nov-00 Satoru V-10.0 base document PR285 + PN436/450/468 
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%\documentstyle[epsfig,a4p,12pt,rotating]{article}
\documentclass[a4p,12pt]{article}
%\documentclass[a4paper,11pt]{article}
\usepackage[]{cite}
\usepackage[]{epsfig}
\usepackage[]{rotating}
%%%%% time %%%%%%%%%
\usepackage[]{time}
%%%%%%%%%%%%%%%%%%%%
%\documentstyle[epsfig,a4,12pt,rotating]{article}

%%%%%%%%%%%%% Draft Version %%%%%%%%%%%%%%%%%
\setlength{\oddsidemargin}{0cm}   %original
\setlength{\evensidemargin}{0cm}  %original
\setlength{\topmargin}{-0.5cm}
\setlength{\textwidth}{16cm}
\setlength{\textheight}{24.5cm}
%%%%%%%%% paper version %%%%%%%%%%%%%%%%%%
%\setlength{\leftmargin}{-5cm}
%\setlength{\topmargin}{-1.0cm}
%\setlength{\textwidth}{16cm}
%\setlength{\textheight}{24.5cm}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%=======================================================================
%       Parameters for the title page
%=======================================================================
%
%  EP number, Date and Version
%
\newcommand{\PNnum}     {OPAL PAPER PR XXX}
%\newcommand{\Date}      {\today}
\newcommand{\Date}      {22 December, 2000}
\newcommand{\Author}    {The OPAL Higgs group}
%=======================================================================
%       Define symbols
%=======================================================================

\def\mrm{\mathrm}
\def\mbf{\mathbf}

\newcommand{\SM}{Standard Model}
\newcommand{\sqrtsp}{\mbox{$\sqrt{s'}$}}
\newcommand{\epm} {\mbox{$\mathrm{e}^+ \mathrm{e}^-$}}
\newcommand{\mpm} {\mbox{$\mu^+ \mu^-$}}
\newcommand{\nprode}{\mbox{$N^{\mathrm{e}^+ \mathrm{e}^-}_{prod}$}}
\newcommand{\nprodm}{\mbox{$N^{\mu^+ \mu^-}_{prod}$}}
\newcommand{\nexpe}{\mbox{$N_{exp}^{\mathrm{e}^+ \mathrm{e}^-}$}}
\newcommand{\nexpm}{\mbox{$N_{exp}^{\mu^+ \mu^-}$}}
\newcommand{\nexpt}{\mbox{$N_{exp}^{total}$}}
\newcommand{\bZo}{{\bf \mbox{$\mathrm Z}^0$}}
\newcommand{\Hosm}{\mbox{$\mathrm{H}^{0}_{\mathrm{SM}}$}}
\newcommand{\Wp}{\mbox{$\mathrm{W}^+$}}
\newcommand{\Wm}{\mbox{$\mathrm{W}^-$}}
\newcommand{\Hpm}{\mbox{$\mathrm{H}^{\pm}$}}
\newcommand{\Hp}{\mbox{$\mathrm{H}^+$}}
\newcommand{\Hm}{\mbox{$\mathrm{H}^-$}}
\newcommand {\HH}{\Hp\Hm}
\newcommand{\ZZ}{\mbox{$\mathrm{Z}^{0}{\mathrm{Z}^{0}}^{(*)}$}}
\newcommand{\sctop}{\mbox{$\tilde{\mathrm{t}}$}}
\newcommand{\msctop}{\mbox{$m_{\tilde{\mathrm{t}}}$}}
\newcommand{\ko}{\mbox{${\tilde{\chi_1}^0}$}}
\newcommand{\koko}{\mbox{${\tilde{\chi_1}^0}{{\tilde{\chi_1}^0}}$}}
\newcommand{\bho}{\mbox{$\boldmath{\mathrm{H}^{0}}$}}
\newcommand{\leplep}{\mbox{$\ell^+\ell^-$}}
\newcommand{\bee}{\mbox{$\boldmath {\mathrm{e}^{+}\mathrm{e}^{-}} $}}
\newcommand{\bmm}{\mbox{$\boldmath {\mu^{+}\mu^{-}} $}}
\newcommand{\bnn}{\mbox{$\boldmath {\nu \bar{\nu}} $}}
\newcommand{\bqq}{\mbox{$\boldmath {\mathrm{q} \bar{\mathrm{q}}} $}}
\newcommand{\qqp}{\mbox{$\mathrm{q\overline{q}^\prime}$}}
\newcommand{\qpq}{\mbox{$\mathrm{q^\prime\overline{q}}$}}
\newcommand{\qppqppp}{
            \mbox{$\mathrm{q^{\prime\prime}\overline{q}^{\prime\prime\prime}}$}}
\newcommand{\tnt}{\mbox{${\tau\nu_{\tau}}$}}
\newcommand{\tpnu}{\mbox{${\tau^+\nu_{\tau}}$}}
\newcommand{\tmnu}{\mbox{${\tau^-{\bar{\nu}}_{\tau}}$}}
\newcommand{\lnu}{\mbox{$\ell\bar\nu_\ell$}}
\newcommand{\tnu}{\mbox{$\tau\nu$}}
\newcommand{\br}{\mbox{$\boldmath {\rightarrow}$}}
\newcommand{\erh}{\mbox{$\mathrm{e}^+\mathrm{e}^-\rightarrow\mathrm{hadrons}$}}
\newcommand{\tpm}{\mbox{$\tau^{\pm}$}}
\newcommand{\pzvis}{\mbox{$\protect P^z_{\mathrm vis}$}}
\newcommand{\evisn}{\mbox{$\protect E_{\mathrm vis}$/$\protect \sqrt{s}$}}
\newcommand{\rvis}{\mbox{$R_{\mrm{vis}}$}}
\newcommand{\zzqqll}{\mbox{$\Zo\Zo^{(*)}\ra\qq\ellell$}}
\newcommand{\wwln}{\mbox{$\mrm{W}^{+}\mrm{W}^{-}
            \ra\mathrm{q}{\bar{\mathrm{q}}}\lnu$}}
\newcommand{\gamgam}{\mbox{$\gamma\gamma$}}
\newcommand{\uu}{\mbox{$\mathrm{u} \bar{\mathrm{u}}$}}
\newcommand{\dd}{\mbox{$\mathrm{d} \bar{\mathrm{d}}$}}
\newcommand{\cc}{\mbox{$\mathrm{c} \bar{\mathrm{c}}$}}
\newcommand{\csbar}{\mbox{$\mathrm{c} \bar{\mathrm{s}}$}}
\newcommand{\cbars}{\mbox{$\bar{\mathrm{c}} \mathrm{s}$}}
\newcommand{\mhs}{\mbox{$m^2_{\mathrm{h}^{0}}$}}
\newcommand{\mHpm}{\mbox{$m_{\mathrm{h}^{\pm}}$}}
\newcommand{\mHp}{\mbox{$m_{\mathrm{H}^+}$}}
\newcommand{\mHm}{\mbox{$m_{\mathrm{H}^-}$}}
\newcommand{\mW}{\mbox{$m_{\mathrm{W}^{\pm}}$}}
\newcommand{\mtop}{\mbox{$m_{\mathrm{t}}$}}
\newcommand{\mstop}{\mbox{$m_{\tilde{\mathrm{t}}}$}}
\newcommand{\mstopL}{\mbox{$m_{\tilde{\mathrm{t}}_{\mathrm{L}}}$}}
\newcommand{\mstopR}{\mbox{$m_{\tilde{\mathrm{t}}_{\mathrm{R}}}$}}
\newcommand{\mb}{\mbox{$m_{\mathrm{b}}$}}
\newcommand{\lpm}{\mbox{$\ell ^+ \ell^-$}}
\newcommand{\G}{\mbox{$\mathrm{GeV}$}}
\newcommand{\Gc}{\mbox{$\mathrm{GeV}$}}
\newcommand{\Gcs}{\mbox{$\mathrm{GeV}$}}
\newcommand{\epsnn}{\mbox{$\epsilon^{\nu\bar{\nu}}$(\%)}}
\newcommand{\Nnn}{\mbox{$N^{\nu \bar{\nu}}_{exp}$}}
\newcommand{\epsll}{\mbox{$\epsilon^{\ell^{+}\ell^{-}}$(\%)}}
\newcommand{\Nll}{\mbox{$N^{\ell^+\ell^-}_{exp}$}}
\newcommand{\Nexp}{\mbox{$N^{total}_{exp}$}}
\newcommand{\kl}{\mbox{$\mathrm{K_{L}}$}}
\newcommand{\dedx}{\mbox{d$E$/d$x$}}
\newcommand{\ie}{\mbox{$i.e.$}}
\newcommand{\sba}{\mbox{$\sin ^2 (\beta -\alpha)$}}
\newcommand{\cba}{\mbox{$\cos ^2 (\beta -\alpha)$}}
\newcommand{\Dbi}{\mbox{${\cal B}_i$}}
\newcommand{\Dbj}{\mbox{${\cal B}_{\mathrm{jet}}$}}
%
\newcommand{\ee}{\mbox{${\mathrm{e}}^+ {\mathrm{e}}^-$}}
\newcommand{\tautau}{\mbox{$\tau^+\tau^-$}}
\newcommand{\mm}{\mbox{$\mu^+\mu^-$}}
\newcommand{\ellell}{\mbox{$\ell^+\ell^-$}}
\newcommand{\qq}         {\mbox{$\mathrm{q}\bar{\mathrm{q}}$}}
\newcommand{\bb}         {\mbox{$\mathrm{b}\bar{\mathrm{b}}$}}
\newcommand{\ff}         {\mbox{$\mathrm{f}\bar{\mathrm{f}}$}}
\newcommand{\nunu}       {\mbox{$\nu\bar{\nu}$}}
\newcommand{\mZ}         {\mbox{$m_{\mathrm{Z}}$}}
\newcommand{\mH}         {\mbox{$m_{\mathrm{H}}$}}
\newcommand{\mh}         {\mbox{$m_{\mathrm{h}}$}}
\newcommand{\mA}         {\mbox{$m_{\mathrm{A}}$}}
%%%%%%%%%%%%%%%%%%
\newcommand{\czcz}{\mbox{$\chi^0_1\chi^0_1$}}
\newcommand{\cz}{\mbox{$\chi^{0}$}}
\newcommand{\co}{\mbox{${\tilde{\chi}_1^0}$}}
\newcommand{\ct}{\mbox{${\tilde{\chi}_2^0}$}}
\newcommand{\coct}{\mbox{$\chi^0_1\chi^0_2$}}
\newcommand{\ctcoz}{\ct\ra\Zs}
\newcommand{\ctcog}{$\ct\ra\co\gamma$}
\newcommand{\hczcz}{\ho\ra\co\co}
\newcommand{\hcoct}{\ho\ra\co\ct}
%%%%%%%%%%%%%%%%%%
\newcommand {\Ho}        {\mbox{$\mathrm{H}^{0}$}}
\newcommand {\Ao}        {\mbox{$\mathrm{A}^{0}$}}
\newcommand {\ho}        {\mbox{$\mathrm{h}^{0}$}}
\newcommand {\Zo}        {\mbox{$\mathrm{Z}^{0}$}}
\newcommand{\Zs}         {\mbox{${\mathrm{Z}}^{*}$}}
\newcommand{\Zgs}        {\mbox{$\mathrm{(Z/\gamma)}^{*}$}}
\newcommand {\Wpm}       {\mbox{$\mathrm{W}^{\pm}$}}
\newcommand{\MH}{M_{\mathrm H}}
\newcommand{\MZ}{M_{\mathrm Z}}
\newcommand{\qqbar}{{\mathrm q}\bar{\mathrm q}}
\newcommand{\nn}{\mbox{$\nu \bar{\nu}$}}
\newcommand{\gaga}       {\mbox{$\gamma\gamma$}}
\newcommand{\WW}         {\mbox{$\mathrm{W}^+\mathrm{W}^-$}}
\newcommand{\pb}         {\mbox{$\mathrm{pb}^{-1}$}}
\newcommand{\tanb}       {\mbox{$\tan\!\beta$}}
\def\mrm       {\mathrm}
\newcommand{\gsim}{\;\raisebox{-0.9ex}
           {$\textstyle\stackrel{\textstyle >}{\sim}$}\;}
\newcommand{\lsim}{\;\raisebox{-0.9ex}{$\textstyle\stackrel{\textstyle<}
           {\sim}$}\;}
\newcommand{\degree}    {^\circ}
\newcommand{\sqrts}     {\sqrt{s}}
%----------------------------
%  Bibliographic references
%----------------------------
%
%     Journal names
%
\newcommand{\PhysLett}  {Phys.~Lett.}
\newcommand{\PRL}       {Phys.~Rev.\ Lett.}
\newcommand{\PhysRep}   {Phys.~Rep.}
\newcommand{\PhysRev}   {Phys.~Rev.}
\newcommand{\NPhys}     {Nucl.~Phys.}
\newcommand{\ZPhysC}[1]    {Z. Phys. {\bf C#1}}
\newcommand{\EurPhysC}[1]    {Eur. Phys. Journal {\bf C#1}}
\newcommand{\PhysLettB}[1] {Phys. Lett. {\bf B#1}}
\newcommand{\CPC}[1]      {Comp.\ Phys.\ Comm.\ {\bf #1}}
\def\etal{\mbox{{\it et al.}}}
\newcommand{\NIM} {Nucl.~Instr.\ Meth.}
\newcommand{\NIMA}[1]   {\NIM\ {\bf A{#1}}}
\newcommand{\ZPhys}  {Z.~Phys.}
\newcommand{\IEEENS} {IEEE Trans.\ Nucl.~Sci.}
%     Collaboration names
%
\newcommand{\OPALColl}  {OPAL Collab.}
%
\newcommand{\ra}        {\mbox{$\rightarrow$}}   % \to can be used as well
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{document}
%=======================================================================
%       Title Page
%=======================================================================
%-----------------------------------------------------------------------
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{titlepage}
\centerline{\LARGE European Organisation for Nuclear Research}
\bigskip
\begin{flushright}
      CERN-EP/2000-156 \\ 
      \Date
\end{flushright}

\begin{center}{\LARGE\bf Search for the Standard Model Higgs Boson \\
in {\boldmath \ee\unboldmath} Collisions at 
{\boldmath $\sqrt{s} \approx$ \unboldmath}192--209~GeV}
\end{center}
 \bigskip
\begin{center}
{\LARGE The OPAL Collaboration}

\bigskip
\bigskip

%{\bf \Large Comments to: Satoru.Yamashita@cern.ch, Tom.Junk@cern.ch and Pauline.Gagnon@cern.ch} \\
%{\bf \large by Thursday 14 December 13:00 CERN Time, please.} \\

%\bigskip
% {\huge {\bf Version 4.2.2 - Nearly Final}}\\
% {\large \today ~~\now}\\
% {\large \today }\\

\end{center}
\bigskip
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{center}{\large  Abstract}\end{center}
A search for the Standard Model Higgs boson has been performed 
with the OPAL detector at LEP based on the full data sample
collected at $\sqrt{s}\approx$~192--209~GeV in 1999 and 2000,
corresponding to an integrated luminosity
of approximately 426 pb$^{-1}$.
The data are examined for their consistency with
the background-only hypothesis and various Higgs boson mass
hypotheses.   A lower bound of 109.7~GeV is obtained on the
Higgs boson mass at the 95\% confidence level.
At higher masses, the data are consistent with both 
the background and the signal-plus-background hypotheses.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\bigskip\bigskip\bigskip\bigskip

\begin{center}
%  {\large (To be submitted to Physics Letters B)}
%  {\large (Submitted to Physics Letters B)}
  {\large (Accepted by Physics Letters B)}
\end{center}
\bigskip\bigskip
This work is dedicated to the memory of our friends and collaborators,
Professors Shuji Orito and George~A.~Snow.

%\bigskip\bigskip\bigskip
%\begin{center}
%{\bf {Comments To Satoru.Yamashita@cern.ch, Tom.Junk@cern.ch, Pauline.Gagnon@cern.ch
%By Noon, Friday 22 December CERN time, please.}}
%\end{center}

\end{titlepage}

\begin{center}{\Large        The OPAL Collaboration
}\end{center}\bigskip
\begin{center}{
%begin authorlist PLEASE DO NOT DELETE THIS COMMENT
G.\thinspace Abbiendi$^{  2}$,
C.\thinspace Ainsley$^{  5}$,
P.F.\thinspace {\AA}kesson$^{  3}$,
G.\thinspace Alexander$^{ 22}$,
J.\thinspace Allison$^{ 16}$,
G.\thinspace Anagnostou$^{  1}$,
K.J.\thinspace Anderson$^{  9}$,
S.\thinspace Arcelli$^{ 17}$,
S.\thinspace Asai$^{ 23}$,
D.\thinspace Axen$^{ 27}$,
G.\thinspace Azuelos$^{ 18,  a}$,
I.\thinspace Bailey$^{ 26}$,
A.H.\thinspace Ball$^{  8}$,
E.\thinspace Barberio$^{  8}$,
R.J.\thinspace Barlow$^{ 16}$,
R.J.\thinspace Batley$^{  5}$,
T.\thinspace Behnke$^{ 25}$,
K.W.\thinspace Bell$^{ 20}$,
G.\thinspace Bella$^{ 22}$,
A.\thinspace Bellerive$^{  9}$,
G.\thinspace Benelli$^{  2}$,
S.\thinspace Bethke$^{ 32}$,
O.\thinspace Biebel$^{ 32}$,
I.J.\thinspace Bloodworth$^{  1}$,
O.\thinspace Boeriu$^{ 10}$,
P.\thinspace Bock$^{ 11}$,
J.\thinspace B\"ohme$^{ 25}$,
D.\thinspace Bonacorsi$^{  2}$,
M.\thinspace Boutemeur$^{ 31}$,
S.\thinspace Braibant$^{  8}$,
P.\thinspace Bright-Thomas$^{  1}$,
L.\thinspace Brigliadori$^{  2}$,
R.M.\thinspace Brown$^{ 20}$,
H.J.\thinspace Burckhart$^{  8}$,
J.\thinspace Cammin$^{  3}$,
P.\thinspace Capiluppi$^{  2}$,
R.K.\thinspace Carnegie$^{  6}$,
B.\thinspace Caron$^{ 28}$,
A.A.\thinspace Carter$^{ 13}$,
J.R.\thinspace Carter$^{  5}$,
C.Y.\thinspace Chang$^{ 17}$,
D.G.\thinspace Charlton$^{  1,  b}$,
P.E.L.\thinspace Clarke$^{ 15}$,
E.\thinspace Clay$^{ 15}$,
I.\thinspace Cohen$^{ 22}$,
J.\thinspace Couchman$^{ 15}$,
A.\thinspace Csilling$^{ 15,  i}$,
M.\thinspace Cuffiani$^{  2}$,
S.\thinspace Dado$^{ 21}$,
G.M.\thinspace Dallavalle$^{  2}$,
S.\thinspace Dallison$^{ 16}$,
A.\thinspace De Roeck$^{  8}$,
E.A.\thinspace De Wolf$^{  8}$,
P.\thinspace Dervan$^{ 15}$,
K.\thinspace Desch$^{ 25}$,
B.\thinspace Dienes$^{ 30,  f}$,
M.S.\thinspace Dixit$^{  7}$,
M.\thinspace Donkers$^{  6}$,
J.\thinspace Dubbert$^{ 31}$,
E.\thinspace Duchovni$^{ 24}$,
G.\thinspace Duckeck$^{ 31}$,
I.P.\thinspace Duerdoth$^{ 16}$,
P.G.\thinspace Estabrooks$^{  6}$,
E.\thinspace Etzion$^{ 22}$,
F.\thinspace Fabbri$^{  2}$,
M.\thinspace Fanti$^{  2}$,
L.\thinspace Feld$^{ 10}$,
P.\thinspace Ferrari$^{ 12}$,
F.\thinspace Fiedler$^{  8}$,
I.\thinspace Fleck$^{ 10}$,
M.\thinspace Ford$^{  5}$,
A.\thinspace Frey$^{  8}$,
A.\thinspace F\"urtjes$^{  8}$,
D.I.\thinspace Futyan$^{ 16}$,
P.\thinspace Gagnon$^{ 12}$,
J.W.\thinspace Gary$^{  4}$,
G.\thinspace Gaycken$^{ 25}$,
C.\thinspace Geich-Gimbel$^{  3}$,
G.\thinspace Giacomelli$^{  2}$,
P.\thinspace Giacomelli$^{  8}$,
D.\thinspace Glenzinski$^{  9}$,
J.\thinspace Goldberg$^{ 21}$,
C.\thinspace Grandi$^{  2}$,
K.\thinspace Graham$^{ 26}$,
E.\thinspace Gross$^{ 24}$,
J.\thinspace Grunhaus$^{ 22}$,
M.\thinspace Gruw\'e$^{ 08}$,
P.O.\thinspace G\"unther$^{  3}$,
A.\thinspace Gupta$^{  9}$,
C.\thinspace Hajdu$^{ 29}$,
G.G.\thinspace Hanson$^{ 12}$,
K.\thinspace Harder$^{ 25}$,
A.\thinspace Harel$^{ 21}$,
M.\thinspace Harin-Dirac$^{  4}$,
M.\thinspace Hauschild$^{  8}$,
C.M.\thinspace Hawkes$^{  1}$,
R.\thinspace Hawkings$^{  8}$,
R.J.\thinspace Hemingway$^{  6}$,
C.\thinspace Hensel$^{ 25}$,
G.\thinspace Herten$^{ 10}$,
R.D.\thinspace Heuer$^{ 25}$,
J.C.\thinspace Hill$^{  5}$,
K.\thinspace Hoffman$^{  8}$,
R.J.\thinspace Homer$^{  1}$,
A.K.\thinspace Honma$^{  8}$,
D.\thinspace Horv\'ath$^{ 29,  c}$,
K.R.\thinspace Hossain$^{ 28}$,
R.\thinspace Howard$^{ 27}$,
P.\thinspace H\"untemeyer$^{ 25}$,  
P.\thinspace Igo-Kemenes$^{ 11}$,
K.\thinspace Ishii$^{ 23}$,
A.\thinspace Jawahery$^{ 17}$,
H.\thinspace Jeremie$^{ 18}$,
C.R.\thinspace Jones$^{  5}$,
P.\thinspace Jovanovic$^{  1}$,
T.R.\thinspace Junk$^{  6}$,
N.\thinspace Kanaya$^{ 23}$,
J.\thinspace Kanzaki$^{ 23}$,
G.\thinspace Karapetian$^{ 18}$,
D.\thinspace Karlen$^{  6}$,
V.\thinspace Kartvelishvili$^{ 16}$,
K.\thinspace Kawagoe$^{ 23}$,
T.\thinspace Kawamoto$^{ 23}$,
R.K.\thinspace Keeler$^{ 26}$,
R.G.\thinspace Kellogg$^{ 17}$,
B.W.\thinspace Kennedy$^{ 20}$,
D.H.\thinspace Kim$^{ 19}$,
K.\thinspace Klein$^{ 11}$,
A.\thinspace Klier$^{ 24}$,
S.\thinspace Kluth$^{ 32}$,
T.\thinspace Kobayashi$^{ 23}$,
M.\thinspace Kobel$^{  3}$,
T.P.\thinspace Kokott$^{  3}$,
S.\thinspace Komamiya$^{ 23}$,
R.V.\thinspace Kowalewski$^{ 26}$,
T.\thinspace K\"amer$^{ 25}$,
T.\thinspace Kress$^{  4}$,
P.\thinspace Krieger$^{  6}$,
J.\thinspace von Krogh$^{ 11}$,
D.\thinspace Krop$^{ 12}$,
T.\thinspace Kuhl$^{  3}$,
M.\thinspace Kupper$^{ 24}$,
P.\thinspace Kyberd$^{ 13}$,
G.D.\thinspace Lafferty$^{ 16}$,
H.\thinspace Landsman$^{ 21}$,
D.\thinspace Lanske$^{ 14}$,
I.\thinspace Lawson$^{ 26}$,
J.G.\thinspace Layter$^{  4}$,
A.\thinspace Leins$^{ 31}$,
D.\thinspace Lellouch$^{ 24}$,
J.\thinspace Letts$^{ 12}$,
L.\thinspace Levinson$^{ 24}$,
R.\thinspace Liebisch$^{ 11}$,
J.\thinspace Lillich$^{ 10}$,
C.\thinspace Littlewood$^{  5}$,
A.W.\thinspace Lloyd$^{  1}$,
S.L.\thinspace Lloyd$^{ 13}$,
F.K.\thinspace Loebinger$^{ 16}$,
G.D.\thinspace Long$^{ 26}$,
M.J.\thinspace Losty$^{  7}$,
J.\thinspace Lu$^{ 27}$,
J.\thinspace Ludwig$^{ 10}$,
A.\thinspace Macchiolo$^{ 18}$,
A.\thinspace Macpherson$^{ 28,  l}$,
W.\thinspace Mader$^{  3}$,
S.\thinspace Marcellini$^{  2}$,
T.E.\thinspace Marchant$^{ 16}$,
A.J.\thinspace Martin$^{ 13}$,
J.P.\thinspace Martin$^{ 18}$,
G.\thinspace Martinez$^{ 17}$,
T.\thinspace Mashimo$^{ 23}$,
P.\thinspace M\"attig$^{ 24}$,
W.J.\thinspace McDonald$^{ 28}$,
J.\thinspace McKenna$^{ 27}$,
T.J.\thinspace McMahon$^{  1}$,
R.A.\thinspace McPherson$^{ 26}$,
F.\thinspace Meijers$^{  8}$,
P.\thinspace Mendez-Lorenzo$^{ 31}$,
W.\thinspace Menges$^{ 25}$,
F.S.\thinspace Merritt$^{  9}$,
H.\thinspace Mes$^{  7}$,
A.\thinspace Michelini$^{  2}$,
S.\thinspace Mihara$^{ 23}$,
G.\thinspace Mikenberg$^{ 24}$,
D.J.\thinspace Miller$^{ 15}$,
W.\thinspace Mohr$^{ 10}$,
A.\thinspace Montanari$^{  2}$,
T.\thinspace Mori$^{ 23}$,
K.\thinspace Nagai$^{ 13}$,
I.\thinspace Nakamura$^{ 23}$,
H.A.\thinspace Neal$^{ 33}$,
R.\thinspace Nisius$^{  8}$,
S.W.\thinspace O'Neale$^{  1}$,
F.G.\thinspace Oakham$^{  7}$,
F.\thinspace Odorici$^{  2}$,
A.\thinspace Oh$^{  8}$,
A.\thinspace Okpara$^{ 11}$,
M.J.\thinspace Oreglia$^{  9}$,
S.\thinspace Orito$^{ 23}$,
C.\thinspace Pahl$^{ 32}$,
G.\thinspace P\'asztor$^{  8, i}$,
J.R.\thinspace Pater$^{ 16}$,
G.N.\thinspace Patrick$^{ 20}$,
J.E.\thinspace Pilcher$^{  9}$,
J.\thinspace Pinfold$^{ 28}$,
D.E.\thinspace Plane$^{  8}$,
B.\thinspace Poli$^{  2}$,
J.\thinspace Polok$^{  8}$,
O.\thinspace Pooth$^{  8}$,
A.\thinspace Quadt$^{  8}$,
K.\thinspace Rabbertz$^{  8}$,
C.\thinspace Rembser$^{  8}$,
P.\thinspace Renkel$^{ 24}$,
H.\thinspace Rick$^{  4}$,
N.\thinspace Rodning$^{ 28}$,
J.M.\thinspace Roney$^{ 26}$,
S.\thinspace Rosati$^{  3}$, 
K.\thinspace Roscoe$^{ 16}$,
A.M.\thinspace Rossi$^{  2}$,
Y.\thinspace Rozen$^{ 21}$,
K.\thinspace Runge$^{ 10}$,
O.\thinspace Runolfsson$^{  8}$,
D.R.\thinspace Rust$^{ 12}$,
K.\thinspace Sachs$^{  6}$,
T.\thinspace Saeki$^{ 23}$,
O.\thinspace Sahr$^{ 31}$,
E.K.G.\thinspace Sarkisyan$^{  8,  m}$,
C.\thinspace Sbarra$^{ 26}$,
A.D.\thinspace Schaile$^{ 31}$,
O.\thinspace Schaile$^{ 31}$,
P.\thinspace Scharff-Hansen$^{  8}$,
M.\thinspace Schr\"oder$^{  8}$,
M.\thinspace Schumacher$^{ 25}$,
C.\thinspace Schwick$^{  8}$,
W.G.\thinspace Scott$^{ 20}$,
R.\thinspace Seuster$^{ 14,  g}$,
T.G.\thinspace Shears$^{  8,  j}$,
B.C.\thinspace Shen$^{  4}$,
C.H.\thinspace Shepherd-Themistocleous$^{  5}$,
P.\thinspace Sherwood$^{ 15}$,
G.P.\thinspace Siroli$^{  2}$,
A.\thinspace Skuja$^{ 17}$,
A.M.\thinspace Smith$^{  8}$,
G.A.\thinspace Snow$^{ 17}$,
R.\thinspace Sobie$^{ 26}$,
S.\thinspace S\"oldner-Rembold$^{ 10,  e}$,
S.\thinspace Spagnolo$^{ 20}$,
F.\thinspace Spano$^{  9}$,
M.\thinspace Sproston$^{ 20}$,
A.\thinspace Stahl$^{  3}$,
K.\thinspace Stephens$^{ 16}$,
D.\thinspace Strom$^{ 19}$,
R.\thinspace Str\"ohmer$^{ 31}$,
L.\thinspace Stumpf$^{ 26}$,
B.\thinspace Surrow$^{  8}$,
S.D.\thinspace Talbot$^{  1}$,
S.\thinspace Tarem$^{ 21}$,
M.\thinspace Tasevsky$^{  8}$,
R.J.\thinspace Taylor$^{ 15}$,
R.\thinspace Teuscher$^{  9}$,
J.\thinspace Thomas$^{ 15}$,
M.A.\thinspace Thomson$^{  5}$,
E.\thinspace Torrence$^{  9}$,
S.\thinspace Towers$^{  6}$,
D.\thinspace Toya$^{ 23}$,
T.\thinspace Trefzger$^{ 31}$,
I.\thinspace Trigger$^{  8}$,
Z.\thinspace Tr\'ocs\'anyi$^{ 30,  f}$,
E.\thinspace Tsur$^{ 22}$,
M.F.\thinspace Turner-Watson$^{  1}$,
I.\thinspace Ueda$^{ 23}$,
B.\thinspace Vachon$^{ 26}$,
C.F.\thinspace Vollmer$^{ 31}$,
P.\thinspace Vannerem$^{ 10}$,
M.\thinspace Verzocchi$^{  8}$,
H.\thinspace Voss$^{  8}$,
J.\thinspace Vossebeld$^{  8}$,
D.\thinspace Waller$^{  6}$,
C.P.\thinspace Ward$^{  5}$,
D.R.\thinspace Ward$^{  5}$,
P.M.\thinspace Watkins$^{  1}$,
A.T.\thinspace Watson$^{  1}$,
N.K.\thinspace Watson$^{  1}$,
P.S.\thinspace Wells$^{  8}$,
T.\thinspace Wengler$^{  8}$,
N.\thinspace Wermes$^{  3}$,
D.\thinspace Wetterling$^{ 11}$
J.S.\thinspace White$^{  6}$,
G.W.\thinspace Wilson$^{ 16}$,
J.A.\thinspace Wilson$^{  1}$,
T.R.\thinspace Wyatt$^{ 16}$,
S.\thinspace Yamashita$^{ 23}$,
V.\thinspace Zacek$^{ 18}$,
D.\thinspace Zer-Zion$^{  8,  k}$
%end authorlist PLEASE DO NOT DELETE THIS COMMENT
}\end{center}\bigskip
\bigskip
%begin institutes
$^{  1}$School of Physics and Astronomy, University of Birmingham,
Birmingham B15 2TT, UK
\newline
$^{  2}$Dipartimento di Fisica dell' Universit\`a di Bologna and INFN,
I-40126 Bologna, Italy
\newline
$^{  3}$Physikalisches Institut, Universit\"at Bonn,
D-53115 Bonn, Germany
\newline
$^{  4}$Department of Physics, University of California,
Riverside CA 92521, USA
\newline
$^{  5}$Cavendish Laboratory, Cambridge CB3 0HE, UK
\newline
$^{  6}$Ottawa-Carleton Institute for Physics,
Department of Physics, Carleton University,
Ottawa, Ontario K1S 5B6, Canada
\newline
$^{  7}$Centre for Research in Particle Physics,
Carleton University, Ottawa, Ontario K1S 5B6, Canada
\newline
$^{  8}$CERN, European Organisation for Nuclear Research,
CH-1211 Geneva 23, Switzerland
\newline
$^{  9}$Enrico Fermi Institute and Department of Physics,
University of Chicago, Chicago IL 60637, USA
\newline
$^{ 10}$Fakult\"at f\"ur Physik, Albert Ludwigs Universit\"at,
D-79104 Freiburg, Germany
\newline
$^{ 11}$Physikalisches Institut, Universit\"at
Heidelberg, D-69120 Heidelberg, Germany
\newline
$^{ 12}$Indiana University, Department of Physics,
Swain Hall West 117, Bloomington IN 47405, USA
\newline
$^{ 13}$Queen Mary and Westfield College, University of London,
London E1 4NS, UK
\newline
$^{ 14}$Technische Hochschule Aachen, III Physikalisches Institut,
Sommerfeldstrasse 26-28, D-52056 Aachen, Germany
\newline
$^{ 15}$University College London, London WC1E 6BT, UK
\newline
$^{ 16}$Department of Physics, Schuster Laboratory, The University,
Manchester M13 9PL, UK
\newline
$^{ 17}$Department of Physics, University of Maryland,
College Park, MD 20742, USA
\newline
$^{ 18}$Laboratoire de Physique Nucl\'eaire, Universit\'e de Montr\'eal,
Montr\'eal, Quebec H3C 3J7, Canada
\newline
$^{ 19}$University of Oregon, Department of Physics, Eugene
OR 97403, USA
\newline
$^{ 20}$CLRC Rutherford Appleton Laboratory, Chilton,
Didcot, Oxfordshire OX11 0QX, UK
\newline
$^{ 21}$Department of Physics, Technion-Israel Institute of
Technology, Haifa 32000, Israel
\newline
$^{ 22}$Department of Physics and Astronomy, Tel Aviv University,
Tel Aviv 69978, Israel
\newline
$^{ 23}$International Centre for Elementary Particle Physics and
Department of Physics, University of Tokyo, Tokyo 113-0033, and
Kobe University, Kobe 657-8501, Japan
\newline
$^{ 24}$Particle Physics Department, Weizmann Institute of Science,
Rehovot 76100, Israel
\newline
$^{ 25}$Universit\"at Hamburg/DESY, II Institut f\"ur Experimental
Physik, Notkestrasse 85, D-22607 Hamburg, Germany
\newline
$^{ 26}$University of Victoria, Department of Physics, P O Box 3055,
Victoria BC V8W 3P6, Canada
\newline
$^{ 27}$University of British Columbia, Department of Physics,
Vancouver BC V6T 1Z1, Canada
\newline
$^{ 28}$University of Alberta,  Department of Physics,
Edmonton AB T6G 2J1, Canada
\newline
$^{ 29}$Research Institute for Particle and Nuclear Physics,
H-1525 Budapest, P O  Box 49, Hungary
\newline
$^{ 30}$Institute of Nuclear Research,
H-4001 Debrecen, P O  Box 51, Hungary
\newline
$^{ 31}$Ludwigs-Maximilians-Universit\"at M\"unchen,
Sektion Physik, Am Coulombwall 1, D-85748 Garching, Germany
\newline
$^{ 32}$Max-Planck-Institute f\"ur Physik, F\"ohring Ring 6,
80805 M\"unchen, Germany
\newline
$^{ 33}$Yale University,Department of Physics,New Haven, 
CT 06520, USA
\newline
%end institutes
\bigskip\newline
%begin notes
$^{  a}$ and at TRIUMF, Vancouver, Canada V6T 2A3
\newline
$^{  b}$ and Royal Society University Research Fellow
\newline
$^{  c}$ and Institute of Nuclear Research, Debrecen, Hungary
\newline
$^{  e}$ and Heisenberg Fellow
\newline
$^{  f}$ and Department of Experimental Physics, Lajos Kossuth University,
 Debrecen, Hungary
\newline
$^{  g}$ and MPI M\"unchen
\newline
$^{  i}$ and Research Institute for Particle and Nuclear Physics,
Budapest, Hungary
\newline
$^{  j}$ now at University of Liverpool, Dept of Physics,
Liverpool L69 3BX, UK
\newline
$^{  k}$ and University of California, Riverside,
High Energy Physics Group, CA 92521, USA
\newline
$^{  l}$ and CERN, EP Div, 1211 Geneva 23
\newline
$^{  m}$ and Tel Aviv University, School of Physics and Astronomy,
Tel Aviv 69978, Israel.
%end notes


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\newpage
\widowpenalty=1000
\section{Introduction}
In the Standard Model~\cite{sm}, the Higgs mechanism~\cite{higgs} gives
mass to the electroweak gauge bosons, thus allowing
the unification of the electromagnetic and weak interactions.
%The existence of the Higgs boson is one of the most important
Whether the Higgs boson exists is one of the most important
open questions in particle physics.
A number of improvements were made to the LEP collider for the year 2000
data taking, which increased the Higgs discovery potential, extending the
sensitivity of the Higgs boson search to approximately 115 GeV if the data
from all four LEP experiments are combined.
The combination of the preliminary Higgs boson search
results of the four LEP 
experiments~\cite{higgs_piktalk,higgs_otherlep} 
shows an excess of candidates which may indicate the production of
a Standard Model Higgs boson with a mass near 115 GeV.
In this letter we present the results of a search
for the Standard Model Higgs boson with
the OPAL detector at LEP, considering particularly the mass
hypothesis of 115 GeV.

Approximately 426~\pb\ of e$^+$e$^-$ annihilation data were collected
by OPAL in the years 1999 and 2000 at centre-of-mass
energies in the range 192--209 GeV; this data sample is used for the
analyses presented in this letter.
Searches are performed for 
the ``Higgs-strahlung'' process
\ee\ra\Ho\Zo\ra\Ho\ff, where \Ho\  is 
the \SM\ Higgs boson,
and
\ff\ is a fermion-antifermion pair from the \Zo\ decay.
For the \Ho\nunu\ (\Ho\ee) final state, the contribution from 
the $\WW$ ($\Zo\Zo$) fusion process
is also taken into account.
%Only the dominant decays of the Higgs boson 
%into \bb\  pairs and \tautau\  pairs are considered here. 
Only the decays of the Higgs boson 
into \bb\  and \tautau\ are considered here. 
OPAL has already reported results from the \SM\ Higgs boson search at 
e$^+$e$^-$ centre-of-mass energies up to 189 GeV~\cite{pr189,prold}, where
a lower mass limit of $\mH>91.0$~GeV was obtained at the 
$95\%$ confidence level. 
A similar search procedure is applied here. 
All data were
processed with the most up-to-date detector calibrations available. For
future publications more refined analyses and 
the final detector calibrations will be used.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\section{OPAL Detector, Data and Monte Carlo Samples}\label{sect:detector}
%=====================================================================%

Details of the OPAL detector can be found in~\cite{detector}.
The data used in the analyses correspond to integrated luminosities 
of approximately 216 pb$^{-1}$ at 192--202 GeV, 80 pb$^{-1}$
at 203--206 GeV, and 130 pb$^{-1}$ at centre-of-mass energies 
higher than 206 GeV.  The total luminosity used to search for
the Higgs boson varies by $\pm$2\% from channel to channel,
due to slightly different requirements
on the operational status of different detector elements.
During 2000 (1999), data were taken at
$\sqrt{s}=200$-209 GeV (192-202 GeV) with a luminosity-weighted mean
centre-of-mass energy of 206.1 (197.6) GeV. 

A variety of Monte Carlo samples was generated 
at centre-of-mass energies between 192 and 210 GeV.
Higgs boson production is modelled with the HZHA3 generator~\cite{HZHA3}
for a wide range of Higgs boson masses.  The size of these samples
varies from 2000 to 10000 events for each mass and at each centre-of-mass energy.
The background processes are simulated with typically more than 50 times the
statistics of the corresponding data sample.
The process \Zgs\ra\qq($\gamma$) is modelled with
the KK2f generator using CEEX~\cite{CEEX} 
for the modelling of the initial state radiation.  
%The PYTHIA~\cite{pythia} generator is used to estimate the
%systematic uncertainty on the \Zgs\ra\qq($\gamma$) background.
The four-fermion processes (4f) are simulated using
grc4f~\cite{grc4f}.
% and KORALW~\cite{koralW} is used to estimate the
%systematic uncertainties on the 4f background rates.
The two-photon and other two-fermion processes
have a negligible impact on the results.
The hadronisation process is simulated with 
JETSET/PYTHIA~\cite{pythia} with parameters
described in~\cite{opaltune}.
In each search channel, the estimates of the signal efficiency and 
the selected background rate depend strongly on the centre-of-mass energy 
and are thus interpolated on a fine grid.
For each Monte Carlo sample, the full detector response is simulated 
in detail as described in~\cite{gopal}.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\section{Analysis Procedures}
\label{sect:analysisprocedures}

We search for  
Higgs production
in the following final
states: \Ho\Zo\ra\bb\qq\  (four-jet channel), \Ho\Zo\ra\bb\nn\ 
(missing-energy channel),
\Ho\Zo\ra\bb\tautau\ and \tautau\qq\
(tau channels), \Ho\Zo\ra\bb\ee\ and \bb\mm\ (electron and
muon channels).  In each channel, 
a preselection is applied to ensure that the events are well measured
and are consistent with the desired signal topology. 
A likelihood selection combining 6 to 10
variables depending on the search channel
is then used to further enrich the signal.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
We use the same analysis techniques described in a 
previous publication~\cite{pr189}, namely
event reconstruction, b-flavour tagging, lepton (electron,
muon and tau) identification and kinematic fits to reconstruct the Higgs
boson mass. %except for small cut optimisation for higher-energy data.
 The b-tagging variable ${\cal B}$ is evaluated for each jet
 to distinguish jets containing b-hadrons from those that do not.
  The tracking and b-tagging performance in the Monte Carlo simulation 
  are tuned using 
  8.2~pb$^{-1}$ of calibration data 
  collected at $\sqrt{s}\approx\mZ$ at intervals during 1999 and 2000 
  with the same detector
  configuration and operating conditions as the high-energy data.
  Figure~\ref{fig:btag}(a) shows the distribution of
  ${\cal B}$ for the calibration data. 
  Comparisons between the data and the Monte Carlo simulation are
  shown in Figure~\ref{fig:btag}(b) for
  jets which are found opposite to jets passing or failing
  the b-tagging requirement.
  The tagging efficiency for b-flavoured (udsc-flavoured) jets 
  is modelled by the Monte Carlo simulation to within an 
  accuracy of 2\% (5\%).  
  

The performance of the b-tagging 
for the data taken at $\sqrt{s}\geq 192$~GeV
is checked with samples of
$\qq(\gamma)$ events by selecting hadronic 
events with the mass of the $\qq$ system near \mZ.
Figure~\ref{fig:btag}(c) shows the b-tagging variable $\cal{B}$ 
for jets opposite b-tagged jets in the 2000 sample.
The efficiency for tagging udsc flavours is also
checked by computing ${\cal B}$ for the jets in a sample of
${\mathrm {W^{+}W^{-}\rightarrow q{\overline q}}\ell{\overline \nu}}$ 
($\ell$=e or $\mu$)
obtained with the selection
used to measure the \WW\ cross-section~\cite{ref:wwxs}
as shown in Figure~\ref{fig:btag}(d).
The expectation from the \SM\ Monte Carlo describes the data
within the relative statistical uncertainty of 5--10\%.
The results of these cross-checks are not used
in the evaluation of the systematic uncertainties described below.

%\subsection{Systematic Errors}
\label{sec:syserror}

Sources of systematic uncertainties are investigated for their effect
on the signal detection efficiencies and the Standard 
Model backgrounds.
The error from the modelling of the likelihood selection input variables
on the background (signal) rates
is 4--8\% (1--4\%), depending on the channel.  These uncertainties are
evaluated based on comparisons of the distributions of the variables
in the data and the Monte Carlo.
%The error from the modelling of the likelihood selection input variables
%is based on comparisons of their distributions
%in the data and the Monte Carlo and is a 4--8\% (1--4\%) 
%on the background (signal) rates.
Comparisons of alternative Monte Carlo generators 
for the backgrounds~\cite{CEEX,grc4f,pythia,koralW}
account for an additional 3--11\% uncertainty in the background rates.
The uncertainty in the four-fermion cross-section is taken
to be $\pm 2$\%~\cite{ref:4funcertainty}.
%
%
The uncertainties on the detector performance, such as
the spatial resolution of the tracking and the modelling of the efficiency of the silicon
microvertex detector, are evaluated source by source with Monte Carlo studies.
Recent improvements in the knowledge of 
heavy quark production processes and decays, such as 
the b-hadron charged decay multiplicity~\cite{LEPEWWG} and
the gluon splitting rate to heavy quarks~\cite{gqq-spl}, 
are taken into account in the
analyses by reweighting Monte Carlo events.
The modelling of the b-hadron production and decay processes is constrained by
various measurements summarized %by the LEP Heavy Flavour Working Group
in~\cite{LEPEWWG}; residual uncertainties in these measurements result
in systematic uncertainties here.
In particular, the b-hadron charged decay multiplicity $n_B$
is varied within $n_B = 4.955\pm 0.062$.
The uncertainties from the fragmentation functions 
for b- and c-quarks are obtained by adjusting the mean 
energy $\langle x_E\rangle$ within the range allowed by the measurements.
The charm and bottom-flavoured hadron lifetimes are varied 
within their
errors with negligible effect on all search channels.
The total uncertainties on the background (signal) rates
are 
%approximately 
11--15\% (5--6\%) varying from channel
to channel.


%==========================================================================%
\subsection{\label{sect:sm4jet} 
Event Selections and Mass Reconstruction}
%==========================================================================%

The preselection requirements in the four-jet channel
are identical to those of~\cite{pr189}.
After the preselection, a likelihood selection based on eight variables
is applied.
For each selected candidate,
two of the jets are associated to the $\Ho$
using a likelihood method based on
the kinematic fit result and the b-tagging information. 
The mass determined by a 
${\mathrm{H^{0}Z^{0}}}$ 5C kinematic fit for the chosen jet pair gives 
the reconstructed mass of the Higgs boson candidate, 
$m^{\mathrm{rec}}_{\mathrm{H}}$.
Because of the 
constraints of the kinematic fit, 
$m^{\mathrm{rec}}_{\mathrm{H}}<\sqrt{s}-\mZ$.
The variables used in the likelihood selection 
for the 1999 data are the same as those used in our earlier analysis~\cite{pr189}.
For the 2000 data, however, one variable, the $\chi^{2}$ probability 
of the ${\mathrm{H^{0}Z^{0}}}$ 5C kinematic fit,
is replaced by the $\chi^{2}$ probability of a fit imposing an equal-mass constraint
as used in the OPAL W mass measurement~\cite{WWpaper}
in order to further suppress the $\Zo\Zo$ background.

The selection of the missing-energy channel is very similar
to~\cite{pr189}.
%and the analysis applied to the 1999 data also differs
%slightly from that applied to the 2000 data.
The notable changes are:
1) tightening the requirement on the maximum
fraction of the visible energy
in the angular region $|\cos{\theta}| > 0.90$ from 50\% to 20\%
in order to further suppress $\qq(\gamma)$ background 
(changed only in the 2000 analysis);
2) a looser requirement on the missing mass  
which is now selected in the range from 40 to 140~GeV.
%2) a looser requirement on the missing mass  
%$m_{\mathrm{miss}}$ which is now selected in the
%$40~\mathrm{GeV}< m_{\mathrm{miss}} <140$~GeV range.
%(cut-5 in Ref.~\cite{pr189}).
Other small changes correspond to the scaling of cut values with $\sqrt{s}$
for variables related to the visible momenta.
In the construction of the likelihood selection,
two new variables are included:
1) the thrust value of the event, and 2) 
the angle between the missing momentum 
and the direction of the most energetic jet.
This last variable adds discrimination power especially against
the process 
$\mathrm {W^{+}W^{-}\rightarrow q{\overline q}}\ell{\overline \nu}$
%semileptonically decaying W-pair events, 
%$\mathrm {W^{+}W^{-}\rightarrow q{\overline q}}\ell{\overline \nu}$,
in which
the charged lepton is close to one of the jet axes.
The reconstructed Higgs boson mass $m^{\mathrm{rec}}_{\mathrm{H}}$
is evaluated using a kinematic fit constraining
the missing mass to the \Zo\ mass. 
%The reconstructed Higgs boson mass $m^{\mathrm{rec}}_{\mathrm{H}}$
%is evaluated using a kinematic fit constraining the total energy
%and momentum of the event, and also constraining
%the missing mass to the \Zo\ mass. 
Because of the fit constraints,
$m^{\mathrm{rec}}_{\mathrm{H}}<\sqrt{s}-\mZ$.


The event selections in the tau, electron and muon channels are
identical to the ones used in \cite{pr189}.
For the tau channel the reconstructed
Higgs boson mass is evaluated (see \cite{pr189}) with the 3C 
kinematic fit  
with the largest $\chi^2$ probability
fixing either the
tau pair invariant mass or the jet pair 
invariant mass to the \Zo\ mass.
The reconstructed Higgs boson mass 
is determined by the recoil mass of the
electron pair in the electron channel, and with the results of a
4C kinematic fit constraining energy and momentum in the muon channel.
There is no upper bound of $m^{\mathrm{rec}}_{\mathrm{H}}$ at
$\sqrt{s}-\mZ$ in the electron and muon channels.

%===========================================================================
%===========================================================================
The numbers of events selected in each analysis 
after preselection
and after the final likelihood selection are shown
in Table~\ref{tab:tab1new} for the data taken at $\sqrt{s}\approx 192-209$ GeV.
%The table also 
%summarises the efficiencies
%and numbers of expected 
%\SM\ Higgs boson signal.
The errors on the background and signal expectations 
are the sums in quadrature of the individual systematic uncertainties.
%
Distributions of the selection likelihood values ${\cal L}^{\rm H^0Z^0}$
in all channels are shown in Figure~\ref{fig:likeout}.
%
The number of selected events in all search channels 
is 156 with 146.1$\pm$11.9 expected from \SM\ background
processes.

The distributions of the reconstructed masses 
of the selected events are shown 
in Figure~\ref{fig:sm2000loose}.
Note that all data taken in the wide $\sqrt{s}$ range from 192 to 209~GeV
are summed in the figure, while the expected 
signal rates strongly depend on $\sqrt{s}$. 
% which reduces the sensitivity for the signal.
% hence the separation of the signal 
% from the background are small in the figure.
The method used to optimise the sensitivity
to the signal is described in Section~\ref{sec:clmethod}.
The background accumulation at high reconstructed
mass in the four-jet channel
is dominated by \qq\ events and jet-pairing combinatorial backgrounds
from the \Zo\Zo\ process.
The \qq\ background in the missing-energy channel also clusters 
at high reconstructed mass because \qq\ events 
passing the selection requirements
are largely composed of events with two or more undetected,
energetic initial state radiation
photons with a small momentum
sum along the beam direction.  
The jets in such events are nearly back-to-back, 
which results in values of $m^{\mathrm{rec}}_{\mathrm{H}}$ near the maximum
kinematically allowed in the fits, $\sqrt{s}-\mZ$.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\subsection{Confidence Level Calculations}
\label{sec:clmethod}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

After the event selections, 
all results from the various search channels 
are combined  to test for the presence of a \SM\ Higgs boson signal.
Previous data taken at centre-of-mass energies near or below 189~GeV
have a negligible impact on the sensitivity to Higgs boson signals
with $\mH>100$~GeV and are not included.
The cross-sections used in computing the confidence level (CL)
include the effects of $\WW$ and $\Zo\Zo$ fusion processes 
and their interference with the \Ho\Zo\ process
in the missing-energy and electron channels respectively, 
as calculated using HZHA3~\cite{HZHA3}.

%First, a value (``test statistic'') is defined which expresses 
%how signal-like the data are.  
In order to compute the confidence levels, a test statistic is
defined which expresses how signal-like the data are.  
The confidence levels are computed from the test statistic of the
observed data and the expected distributions of the test statistic
in a large number of simulated experiments under two hypotheses:
the background-only hypothesis and the signal+background hypothesis.
The test statistic chosen is the likelihood ratio $Q$, the ratio of
the probability of observing the data given the signal+background hypothesis
to the probability of observing the data given the background-only
hypothesis~\cite{bib:kendallstuartord,LEPHIGGS202}.
The results of all search channels are expressed in fine bins of
discriminating variables, such as $m^{\mathrm{rec}}_{\mathrm{H}}$.
The expected signal strength depends strongly on $\sqrt{s}$, hence
the results are considered separately in fine divisions of $\sqrt{s}$.
In each bin of each channel at each $\sqrts$ the expected Higgs boson signal,
$s_i$, and the Standard Model background rate, $b_i$, are estimated,
and the observed data counts, $n_i$, are reported.
The $s_i$ depend on the mass of the Higgs boson under study (the
``test mass'').   Each bin is considered to be a statistically independent
search obeying Poisson statistics.  The likelihood ratio
$Q$ can then be computed~\cite{LEPHIGGS202} as
$\ln Q=-\sum_i s_i +\sum_i n_i\ln(1+s_i/b_i)$.
Each event has a weight in the sum which depends on the 
signal-to-background ratio in the bin in which it is found; events may
be classified by their local $s/b$ values.
The confidence level for the background hypothesis is
($1-{\mathrm{CL}}_b$)~\cite{LEPHIGGS202}
which is the probability in an ensemble of background-only experiments
of observing a more signal-like $Q$ than is
actually observed: $1-{\mathrm{CL}}_b=P(Q>Q_{\mathrm{obs}}|{\mathrm{background}})$.
A low value of $(1-{\mathrm{CL}}_b)$ indicates an excess of candidates in data 
compared to the expectation from background.  The distribution of
($1-{\mathrm{CL}}_b$) is uniform between~0 and~1 in an ensemble
of background-only experiments.

Similarly, the confidence level for the signal+background hypothesis is
${\mathrm{CL}}_{s+b}=P(Q\le Q_{\mathrm{obs}}|{\mathrm{signal+background}})$,
and is used to exclude the signal+background hypothesis if it has
a small value.
To eliminate the possibility of excluding a signal to which there is
no sensitivity, a third quantity is defined 
${\mathrm{CL}}_s={\mathrm{CL}}_{s+b}/{\mathrm{CL}}_b$~\cite{LEPHIGGS202}.
Results are also presented in terms of the signal rate limit 
$n_{95}=g_{\mathrm{min}}\sum_i s_i$, where $g_{\mathrm{min}}$ is the
smallest number such that the signal hypothesis consisting of
$g_{\mathrm{min}}s_i$ in each bin yields ${\mathrm{CL}}_s=0.05$.  The
signal rate limit $n_{95}$ depends on the test mass.
The technique used to perform the computation of the confidence levels is the same
as is used in~\cite{prold}.

In our previous papers, the only discriminating variables used were the values
of $m^{\mathrm{rec}}_{\mathrm{H}}$.  Here, the discriminating power is improved
by combining $m^{\mathrm{rec}}_{\mathrm{H}}$ with other variables.
In the four-jet channel, after the jet pairing assignment
and mass determination,
a new test-mass-dependent variable 
${\cal {D}}_{mass}$ is formed using a likelihood technique 
in order to investigate the compatibility with the signal production hypothesis
for a Higgs boson of a specific test mass.
The variable ${\cal {D}}_{mass}$ is based on the following four quantities:
1) the combined b-tagging variable ${\cal B}_{2jet}^{H}$ 
defined by ${\cal B}_{2jet}^{H} \equiv {\cal {B}}_{1} \cdot {\cal {B}}_{2} / ({\cal {B}}_{1} \cdot {\cal {B}}_{2} + (1- {\cal {B}}_{1}) \cdot (1-{\cal {B}}_{2}))$ 
for the two jets with the most significant b~tags;
2) the energy difference between the most energetic and the least energetic
jets in the event;
3) $\beta_{\rm min}$, a selection likelihood 
variable (see~\cite{prold});
%variable (see~\cite{pr189});
and 4) the reconstructed Higgs boson mass $m^{\mathrm{rec}}_{\mathrm{H}}$.
Signal Monte Carlo samples were generated
with Higgs boson masses in 1 GeV steps, 
and ${\cal {D}}_{mass}$ is interpolated between neighbouring test masses.
The distribution of ${\cal D}_{mass}$ is shown for 
a test mass of 115~GeV in Figure~\ref{fig:sm200nem}(a).

In the missing-energy, electron and muon channels,
the selection likelihood value, ${\cal L}^{\rm H^0Z^0}$, 
is used to form a two-dimensional discriminant 
(${\cal L}^{\rm H^0Z^0}$, $m^{\mathrm{rec}}_{\mathrm{H}}$).
The cut on ${\cal L}^{\rm H^0Z^0}$ 
is chosen to optimise the sensitivity of this new discriminant. 
%
%
In Figures~\ref{fig:sm200nem}(b) and (c),
the reconstructed mass distributions are shown in slices of the selection
likelihoods
for the electron and muon channels, and for the missing-energy channel, 
respectively.  In each channel, the enrichment of the signal depends
on both the likelihood value and on $m^{\mathrm{rec}}_{\mathrm{H}}$.
For the tau channels, only the reconstructed mass is used
for the discriminant as in ~\cite{pr189}.

The systematic uncertainties on the signal and background 
expectations in each channel are treated using an 
extension of the method described in~\cite{ref:cousins}. 
Uncertainties described in Section~\ref{sec:syserror} are assumed
to be 100\% correlated if they arise from the same source
in different channels, in the signal and background estimations,
and at different centre-of-mass energies.
The current uncertainty on the beam energy for the 2000 data
is expected to be of the 
order of 100~MeV, and 
would therefore affect the limits by $\sim$~200~MeV.
The uncertainty on the integrated 
luminosity is estimated to be 0.3\%. % and is neglected.
Both of these errors are neglected.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\section{Results}
\label{sec:smcl}


Figure~\ref{fig:smclb}(a) shows $(1-{\mathrm{CL}}_b)$ as a function of the
test mass \mH.  It attains its lowest value of 0.02 at $\mH=107$~GeV,
indicating a local excess of candidates.  
The probability to observe such an excess anywhere in the range
of test masses between 100 and 120~GeV is approximately 10\%, estimated
from the size of the range and the reconstructed mass resolution.
The value of $(1-{\mathrm{CL}}_b)$ observed at \mH=115~GeV is 0.2.
Figure~\ref{fig:smclb}(a) also shows the expected $(1-{\mathrm{CL}}_b)$ in the 
presence of a 115~GeV Higgs boson signal.

The signal rate limit $n_{95}$ is shown as a function of \mH\ in
Figure~\ref{fig:smclb}~(b) together with its median expectation in
an ensemble of background-only experiments.  Figure
~\ref{fig:smclb}~(b) also shows the expected accepted
signal rate.  Where the signal rate curve crosses the $n_{95}$ curve
is the 95\%~CL exclusion limit on \mH, and the expected limit
is where the median expected $n_{95}$ curve crosses the accepted signal
rate curve.  A lower mass bound of 109.7~GeV is obtained, and
the expected limit is 112.5~GeV.  In particular, the hypothesis
\mH=107~GeV is excluded at the 98\% CL (CL$_s=0.02$)
even in the presence of the excess candidates
because the excess in the data is not large enough to be consistent with
the expected signal rate from a Standard Model Higgs boson
of that mass.
%% 108.0 and 112.5  from P. Bock with old e, mu channels.

The candidates with the largest 
weights, $\ln (1+s/b)$, in each channel 
for test masses of 115~GeV are listed in 
Table~\ref{tab:4j-cand}. 
Figure~\ref{fig:sm_evolution} shows 
the distributions of $\ln (1+s/b)$ of each candidate
%the distributions of the logarithm of
%the contribution, $\ln (1+s/b)$, of each candidate
%to the logarithm of the likelihood ratio
as a function of the Higgs boson test mass for the
candidates collected in 1999 and 2000.  The region of test mass for which
a candidate's contribution is significant depends on the mass resolution
of the candidates in the channel, and the normalization of the curve depends
on the candidate b-tags, the kinematic variables, the Higgs boson cross-section
and the local background near the reconstructed candidate mass.
Deviations from smoothness of the curves are due to
Monte Carlo statistics; this uncertainty is included in the
confidence level computation.

The most significant candidate for a Higgs boson search for
a test mass $\mH=115$~GeV
(candidate \#1) is found in the four-jet channel.
For the jet-pairing chosen by the jet-pairing likelihood function, the event
has a reconstructed Higgs boson mass
of 110.7~GeV.   The second most significant candidate (\#2) is also
found in the four-jet channel, with a reconstructed mass of 112.6~GeV.
%The second best combinations determined by 
%the jet-pairing likelihood selection for candidates \#1 and \#2
%have masses of 111.9 and 112.9 GeV, respectively.
No jet pairing yields a reconstructed Higgs boson mass close to
the $\Zo$ mass in either of these two candidates.

The observed low value of 
$(1-{\mathrm{CL}}_b)$ at 107 GeV is caused by candidates
which have relatively high weights 
at around 105--110 GeV seen in Figure~\ref{fig:sm_evolution}.
For the tau channel candidate \#5,
the reconstructed mass is taken from the invariant
mass of the jets after a 3C kinematic fit %(see Ref.~\cite{pr189}) 
where the tau pair mass is constrained to the Z$^0$ mass.
The tau pair mass is 91~GeV if a 2C fit~\cite{pr189}
is performed.
The muon channel candidate \#7 significantly affects
the results of the confidence level calculations around 100--105 GeV
since its likelihood ${\cal L}^{\rm H^0Z^0}$
is very close to one. 

The observed $-2\ln{Q}$
is shown as a function of the test mass \mH\ in
Figure~\ref{fig:minus2lnq}~(a).
%The maximum deviation from the background 
%expectation is observed near \mH=107~GeV, but this
%observation is not consistent with the expected \SM\ 
%cross-section for this signal hypothesis.
Also shown are the 68\% and 95\% probability contours
centred on the median expectation.  Figure~\ref{fig:minus2lnq}~(b)
shows the probability density functions of $-2\ln Q$ for the
signal+background hypothesis with $\mH=115$~GeV, and also for the
background hypothesis.  The separation between the
two hypotheses is not strong.  The background confidence
level ($1-{\mathrm{CL}}_b$)=0.2 is
the integral of the background-only probability density to the left
of the data observation, and ${\mathrm{CL}}_{s+b}=0.4$ is the integral
to the right of the data observation of the signal+background curve.
The data are slightly more
consistent with the presence of a 115 GeV Higgs boson than with the
background alone.


%=====================================================================%
%=====================================================================%
%=====================================================================%
%=====================================================================%
\section{Conclusions} 

A search for the Standard Model Higgs boson has been performed 
with the OPAL detector at LEP based on the full data sample
collected at $\sqrt{s}\approx$192--209~GeV in 1999 and 2000.
The largest deviation with respect to the expected \SM\ background
in the confidence level for the background hypothesis, $(1-{\mathrm{CL}}_b)$, 
is observed for a Higgs boson mass of 107 GeV with a 
minimum $(1-{\mathrm{CL}}_b)$ of 0.02, 
but the observed excess is less
significant than is expected for a Standard Model Higgs boson 
with a 107 GeV mass.
A lower bound of 109.7~GeV on the mass of the \SM\ Higgs boson is obtained
at the 95\% confidence level while the median expectation for
the background-only hypothesis is 112.5 GeV.
For a Higgs boson with a mass of 115~GeV,
$(1-{\mathrm{CL}}_b)$ is approximately 0.2 while
CL$_{s+b}$ is approximately 0.4, indicating that the data slightly
favour the hypothesis that a signal is present, but also that the
data are consistent with the background hypothesis.
These data alone provide little discrimination
between the signal+background and background hypotheses
for Higgs boson masses above 112~GeV, but more statistically powerful conclusions may
be reached by combining the data presented here with those of the other
LEP experiments~\cite{LEPHIGGS00COMB}.

\section*{Acknowledgements}

We particularly wish to thank the SL Division for the efficient operation
of the LEP accelerator at all energies
 and for their continuing close cooperation with
our experimental group.  We thank our colleagues from CEA, DAPNIA/SPP,
CE-Saclay for their efforts over the years on the time-of-flight and trigger
systems which we continue to use.  In addition to the support staff at our own
institutions we are pleased to acknowledge the  \\
Department of Energy, USA, \\
National Science Foundation, USA, \\
Particle Physics and Astronomy Research Council, UK, \\
Natural Sciences and Engineering Research Council, Canada, \\
Israel Science Foundation, administered by the Israel
Academy of Science and Humanities, \\
Minerva Gesellschaft, \\
Benoziyo Center for High Energy Physics,\\
Japanese Ministry of Education, Science and Culture (the
Monbusho) and a grant under the Monbusho International
Science Research Program,\\
Japanese Society for the Promotion of Science (JSPS),\\
German Israeli Bi-national Science Foundation (GIF), \\
Bundesministerium f\"ur Bildung und Forschung, Germany, \\
National Research Council of Canada, \\
Research Corporation, USA,\\
Hungarian Foundation for Scientific Research, OTKA T-029328, 
T023793 and OTKA F-023259.

%%%%%%%%%%%% REFERENCES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%=======================================================================
%       References
%=======================================================================

%%%%%%%%%%%% REFERENCES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%=======================================================================
%       References
%=======================================================================
\begin{thebibliography}{99}
%
\bibitem{sm}
S.~Glashow, Nucl.~Phys.~{\bf 22} (1961) 579;\\
S.~Weinberg, Phys.~Rev.~Lett.~{\bf 19} (1967) 1264;\\
A.~Salam, ed. N.~Svartholm, {\it Elementary Particle Theory}, 
Almquist and Wiksells, Stockholm (1968) 367.
%
\bibitem{higgs}
P.W.~Higgs, Phys.~Lett.~{\bf 12} (1964) 132;\\
F.~Englert and R.~Brout, Phys.~Rev.~Lett.~{\bf 13} (1964) 321;\\
G.S.~Guralnik, C.R.~Hagen, and T.W.B.~Kibble,
Phys.~Rev.~Lett.~{\bf 13} (1964) 585.
%
\bibitem{higgs_piktalk} 
P.~Igo-Kemenes, presentation given to
the LEP Experiments Committee open session, 
\mbox{\tt http://lephiggs.web.cern.ch/LEPHIGGS/talks/index.html},
3~November 2000.
%
\bibitem{higgs_otherlep}
ALEPH Collaboration, R.~Barate \etal, Phys.~Lett.~{\bf B495} (2000) 1;\\  
L3 Collaboration, M. Acciarri \etal, Phys.~Lett.~{\bf B495} (2000) 18.
\bibitem{pr189} 
OPAL Collaboration, G.~Abbiendi \etal, Eur.~Phys.~J.~{\bf C12} (2000) 567.
%
\bibitem{prold} 
OPAL Collaboration, G. Abbiendi \etal, Eur. Phys. J. {\bf C7} (1999) 407;\\
OPAL Collaboration, K. Ackerstaff \etal, Eur. Phys. J. {\bf C1} (1998) 425.
%
\bibitem{detector}
OPAL Collaboration, K.~Ahmet \etal, Nucl. Instr. and Meth. 
{\bf A305} (1991) 275;\\
S. Anderson {\it et al.}, Nucl. Instr. and Meth. A403 (1998) 326;\\
B.E.~Anderson {\it et al.}, IEEE Trans. on Nucl. Science 41 (1994) 845;\\
G.~Aguillion {\it et al.}, Nucl. Instr. and Meth. A417 (1998) 266.
%
\bibitem{HZHA3} 
P.~Janot \etal, in {\em Physics at LEP2,} edited by G.~Altarelli, 
T.~Sj\"ostrand and F.~Zwirner, CERN 96-01 Vol.~2, 309. \\
For HZHA3 and HZHA2, 
see {\em http://alephwww.cern.ch/$\sim$janot/Generators.html}.
%
\bibitem{CEEX}
S.~Jadach, B.F.~Ward and Z.~Was, Phys.~Lett.~{\bf B449} (1999) 97.
%
\bibitem{grc4f}
J. Fujimoto \etal, Comp. Phys. Comm. {\bf 100} (1997) 128;\\
{\it Physics at LEP2}, J.~Fujimoto \etal, CERN 96-01, Vol.~2, 30.
%
\bibitem{pythia}
T. Sj\"ostrand, Comp. Phys. Comm. {\bf 82} (1994) 74;\\
T. Sj\"ostrand \etal, {\em High-Energy-Physics Event Generation
with PYTHIA 6.1}, hep-ph/0010017 (2000), to be published in
Comp. Phys. Comm.
%
\bibitem{opaltune}
OPAL Collaboration, G. Alexander \etal, Z. Phys {\bf C69} (1996) 543.
%
\bibitem{gopal}
J. Allison \etal, Nucl. Instr. and Meth. {\bf A317} (1992) 47.
%
\bibitem{ref:wwxs} 
OPAL Collaboration, G.~Abbiendi \etal, Phys.~Lett.~{\bf B493} (2000) 249.
%
\bibitem{koralW} 
M.~Skrzypek \etal, \CPC{94} (1996) 216;\\
M.~Skrzypek \etal, \PhysLettB{372} (1996) 289. 
%
\bibitem{ref:4funcertainty}  
M.W.~Gr\"unewald and G.~Passarino \etal,
{\it Four-Fermion Production in Electron-Positron Collisions}, 
{\tt hep-ph/0005309} (2000).
%
\bibitem{LEPEWWG} ALEPH, DELPHI, L3, OPAL Collaborations and the LEP Electroweak
Working Group and the SLD Heavy Flavour and Electroweak Groups, 
{\it  A Combination of Preliminary Electroweak Measurements and Constraints
on the Standard Model}, CERN-EP/2000-016 (2000), and references therein.
%
%\bibitem{LEPHFEWWG} 
%LEP Heavy Flavour Electroweak Working Group, 
%{\it Input Parameters for the LEP Electroweak Heavy Flavour Results 
%for Summer 1998 Conferences}, 
%LEPHF/98-01 (1998).
%
\bibitem{gqq-spl}
E. Norrbin and T. Sj\"ostrand, 
{\em QCD Radiation off Heavy Particles}, 
{\tt hep-ph/0010012} (2000).
\bibitem{WWpaper}
OPAL Collaboration, G.~Abbiendi \etal, 
{\em Measurement of the Mass and Width of the W Boson in 
${\mathrm{e^+e^-}}$ Collisions at 189 GeV}, 
CERN-EP-2000-099, submitted to Phys. Lett. B.
%
\bibitem{bib:kendallstuartord} 
A.~Stuart and J.~K.~Ord, 
{\it Kendall's Advanced Theory of Statistics}, Vol.~2, Ch.~23
5th Ed., Oxford University Press, New York, (1991).
%
\bibitem{LEPHIGGS202} 
ALEPH, DELPHI, L3, OPAL Collaborations, and
the LEP working group for Higgs boson searches,
{\em Search for Higgs bosons: Preliminary combined results using LEP data 
collected at energies up to 202 GeV,} 
CERN-EP/2000-055 (2000)
%
%\bibitem{pb-method} 
%LEP working group for Higgs boson searches, CERN/LEPC 97-11;\\
%P.~Bock, HD-PY-96/05 (1996).
%
\bibitem{ref:cousins} 
R.D.~Cousins and V.L.~Highland, Nucl.~Instr.~and~Meth. {\bf A320} (1992) 331.
%
\bibitem{LEPHIGGS00COMB} ALEPH, DELPHI, L3 and OPAL Collaborations, and the
LEP Higgs Working Group, in preparation.
%
\end{thebibliography}
\newpage

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%% Cutflow Year 1999+ 2000 (Updated. signal maybe wrong) %%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{table}[tb]
\begin{center}
{\footnotesize
\begin{tabular}{|c||c||r||r||r|r||c|c|}\hline
Channel & Cut & Data & Total bkg. & q\=q($\gamma$) & 4-fermi. & 
\multicolumn{2}{|c|}{Eff. [\%] (signal events)}\\ \cline{7-8}
 &  &  &  &  &  & 110~GeV & 115~GeV \\\hline\hline
Four-jet &Presel.&  3820& 3609.9& 760.8& 2859.4& 85.2 & 86.9 \\
\cline{2-8}
&${\cal L}^{\rm HZ}$ &
      60&    49.8$\pm$6.0 &  12.8&   37.0&45.5 (9.04$\pm$0.41)& 41.8 (2.24$\pm$0.10)\\
\hline\hline
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Missing-E & Presel. & 354& 334.5&  57.0&  277.5 & 56.1 & 49.5\\
\cline{2-8}
&${\cal L}^{\rm HZ}$ &
     68&    69.7$\pm$8.6&  10.6&   59.1&50.0 (4.70$\pm$0.28)& 43.9 (1.68$\pm$0.10)\\
\hline\hline
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Tau&Presel. &  343&   334.5&  57.0&  277.5&48.3&43.3\\
\cline{2-8}
&Final $\mathcal{L}$ &
    8&    11.1$\pm$1.2&   0.4&   10.7&29.5 (0.98$\pm$0.05)& 22.9 (0.25$\pm$0.01)\\
\hline\hline
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Electron&Presel.&  429&   378.6& 171.0&  207.6&72.7&71.3\\
\cline{2-8}
&${\cal L}^{\rm HZ}$ &
   6&     8.5$\pm$1.3&   0.3&    8.2&52.9 (0.66$\pm$0.02)&48.7 (0.17$\pm$0.004)\\
\hline\hline
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Muon&Presel.&  79&    66.2&  36.8&   29.4& 70.3&70.9\\
\cline{2-8}
&${\cal L}^{\rm HZ}$ &
   10&     7.0$\pm$1.0&   0.2&    6.8&59.1 (0.80$\pm$0.02)& 59.9 (0.23$\pm$0.006)\\
\hline
\end{tabular}
}
\caption[]{\label{tab:tab1new}\sl 
  The number of events after preselection 
  and after the final likelihood selection for 
  the 192--209 GeV data and the expected background.
  The errors on the total background and the expected Higgs signal 
  include all systematic errors.
  The last two columns show the detection efficiencies 
  (and the numbers of expected signal events in parentheses) 
  for a Higgs boson with \mH=110~GeV and 115 GeV.  
  For the four-jet channel, the efficiency is computed only
  for \Ho\ra~\bb\ decays, and for the tau channel 
  for the processes \Ho\Zo\ra\tautau(\Ho\ra all) 
  or \Ho\Zo\ra\qq\tautau\ assuming \SM\ branching fractions.
  For other channels, 
  the efficiency is for all decays of the \SM\ Higgs boson.
}
\end{center}
\end{table}


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Candidate Table %%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{table}[htb]
\begin{center}
\begin{footnotesize}
\begin{tabular}{|c|c|c|c|c|c|c|c|}\hline
\multicolumn{8}{|c|}{Candidates} \\\hline
%Candidate \# & Channel & $m{\mathrm{_H^{rec}}}$ & ${\cal L}^{\rm H^0Z^0}$  & 
Candidate & Channel & $m{\mathrm{_H^{rec}}}$ & ${\cal L}^{\rm H^0Z^0}$  & 
$E_{\mathrm{CM}}$ & 
\multicolumn{3}{|c|}{ $s/b$ for $\mH$ (GeV)}\\ \cline{6-8} 
         &       & (GeV)                &   & 
(GeV)             & 
105 & 110 & 115 \\\hline
%%%%%%%%%%
\# 1 ~~&~~Four-jet  ~~&~~ 110.7  ~~&~~ 0.995 ~~&~~206.6~~&~~ 0.64 ~~&~~ 2.09 ~~&~~ 0.70 ~~\\
\# 2 ~~&~~Four-jet  ~~&~~ 112.6  ~~&~~ 0.999 ~~&~~205.4~~&~~ 0.28 ~~&~~ 1.18 ~~&~~ 0.49 ~~\\
\# 3 ~~&~~Missing-Energy ~~&~~ 104.0  ~~&~~ 0.999 ~~&~~205.4~~&~~ 4.55 ~~&~~ 0.96 ~~&~~ 0.28 ~~\\
\# 4 ~~&~~Missing-Energy ~~&~~ 112.1  ~~&~~ 0.853 ~~&~~206.4~~&~~ 0.15 ~~&~~ 0.44 ~~&~~ 0.23 ~~\\
\hline\hline
\# 5 ~~&~~Tau       ~~&~~ 105.3  ~~&~~ 0.993 ~~&~~205.3~~&~~ 4.00 ~~&~~ 0.46 ~~&~~ 0.05 ~~\\
\# 6 ~~&~~Electron  ~~&~~ 124.7  ~~&~~ 0.873 ~~&~~205.4~~&~~ 0.20 ~~&~~ 0.17 ~~&~~ 0.16 ~~\\
\# 7 ~~&~~Muon      ~~&~~ 102.2  ~~&~~ 0.999 ~~&~~205.4~~&~~ 3.02 ~~&~~ 0.38 ~~&~~ 0.04 ~~\\
\hline
%%%%%%%%%% updated 9 Dec. with new e candidate s/b -- Tom
\end{tabular}
\end{footnotesize}
\caption{\label{tab:4j-cand}\sl 
%Candidates in the 2000 data with the largest weights for the 115 GeV Higgs
The candidates with the largest weights for the 115 GeV Higgs
hypothesis in each channel.
The columns labeled $m{\mathrm{_H^{rec}}}$ and ${\cal L}^{\rm H^0Z^0}$ are 
the reconstructed Higgs mass and selection likelihood values, respectively.
The next three columns give the signal to background ratio (s/b) using the
discriminants which are used in the confidence level calculation. 
The s/b values for Higgs boson test masses of 105, 110 and 115 GeV 
are shown.  
For the four-jet and the missing-energy channels, all candidates
with s/b larger than 0.20 for 115 GeV are listed. For the tau, 
electron and muon channels, the candidates with the %highest 
largest s/b for
the 115 GeV hypothesis are listed in the lower portion of the table.
}
\end{center}
\end{table}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\newpage

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%% FIGURES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{figure}[htb]
\vspace*{-0.2cm}
\centerline{\epsfig{file=pr329_01.eps,width=1.2\textwidth}}
\vspace{-3cm}
\caption[]{\label{fig:btag}\sl
The b-tagging performance and modelling for (a--b) calibration data 
taken at $\sqrt{s}=\mZ$ in 2000, and (c--d) at $\sqrt{s}$
between 200--209 GeV in 2000.
(a) The distribution of the b-tagging variable $\cal B$ for jets
in data compared to the Monte Carlo expectation. 
(b) The bin-by-bin difference between data and Monte Carlo simulation
for jets opposite non b-tagged jets (circles) and
for jets opposite b-tagged jets (squares). 
(c) The b-tagging output, $\cal{B}$, for jets opposite b-tagged jets
in a sample of $\qq\gamma$ events,
and (d) for jets in a sample of 
%${\mathrm{ W^{+}W^{-}\rightarrow q{\overline q}}\ell{\overline \nu}}$ events.
${\mathrm {W^{+}W^{-}\rightarrow q{\overline q}}
{\mathrm e^-}{\overline\nu_{\mathrm{e}}}}$ and
${\mathrm {W^{+}W^{-}\rightarrow q{\overline q}}
\mu^-{\overline\nu_{\mu}}}$ events (and charge conjugates).
The  histogram in (d) shows the distribution from the four-fermion
Monte Carlo samples.
}
\end{figure}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\newpage

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%% LH distributions %%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{figure}[ht]
\vspace*{-0.7cm}
\centerline{
\epsfig{file=pr329_02.eps,width=1.2\textwidth}
}
\vspace*{-1cm}
\caption[]{\label{fig:likeout}\sl
The distributions of the likelihood output variables in \Ho\Zo\ searches for
the 1999 and 2000 data in:
(a) the four-jet channel, (b) the missing-energy channel,
(c) the tau channel $\tautau\qq$, (d) the tau channel $\bb$\tautau,
(e) the electron channel and (f) the muon channel.  
OPAL data are shown with points, 
backgrounds with the shaded histograms, 
and
the expectation from a signal with \mH=115~GeV with the dashed histograms
(scaled up by a factor of 100 for visibility.)
}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\newpage

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%% Mass Plots %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{figure}[ht]
\centerline{
\epsfig{file=pr329_03.eps,width=\textwidth}
}
\vspace*{-0.3cm}
\caption[]{\label{fig:sm2000loose}\sl 
The reconstructed mass distribution for the selected events in the 1999 and 2000 data
for (a) the four-jet channel, 
(b) the missing-energy channel,
(c) the tau channels, 
and (d) the electron and muon channels combined.
The first bin in (a) contains all
events with $\chi^2$ probability of the
$\mathrm{H^{0}Z^{0}}$ 5C kinematic fit $< 10^{-5}$ for chosen jet-pairings.
The dark (light) grey area shows the expected contribution from the
$\qq (\gamma)$ (four-fermion) process. The \SM\ signal expectation for 115 GeV is
shown with the very dark histograms on top of the \SM\ backgrounds.
}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\newpage

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%% Slice/Discrminator %%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{figure}[ht]
\vspace*{-1.1cm}
\centerline{
\epsfig{file=pr329_04a.eps,width=0.7\textwidth}
}
\vspace*{-1.5cm}
\centerline{
\epsfig{file=pr329_04bc.eps,width=1.1\textwidth}
}
\vspace*{-0.2cm}
\caption[]{\label{fig:sm200nem}\sl 
(a) The distribution of 
the variable ${\cal D}_{mass}$ 
in the four-jet channel for a test mass of 115 GeV.
(b) The reconstructed mass distribution in the electron and muon channels for 
the likelihood ranges of 0.9--1.0, 0.5--0.9, and range between
the selection cut values (0.2 for the electron channel
and 0.3 for the muon channel) and 0.5.
%(b) Scatter plots for the likelihood values versus the
%reconstructed mass for selected events in data in 2000
%for the missing-energy, electron and muon channels.  
(c) The reconstructed mass distribution in the missing-energy channel for 
the likelihood ranges of 0.8--1.0, 0.5--0.8, and 0.2--0.5.
In all distributions, the data for $\sqrt{s}\ge 204$ GeV are shown
with points, and the expected
$\qq(\gamma)$ backgrounds are shown with
dark-shaded histograms and the expected four-fermion backgrounds are
shown with light-shaded histograms.  The expected distributions from 
a 115 GeV Higgs boson signal are shown with very dark-shaded histograms.
}
\end{figure}

\newpage

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 1-CLb and n95 %%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{figure}[htbp]
\centerline{
\epsfig{file=pr329_05a.eps,width=0.6\textwidth}\\
\epsfig{file=pr329_05b.eps,width=0.6\textwidth}
}
\vspace*{-0.2cm}
\caption[]{\label{fig:smclb}\sl 
(a) The confidence level for the background-only hypothesis, 
$(1-{\mathrm{CL}}_b)$, as a function of the Higgs boson test mass.  
The dotted curve represents the median expectation assuming the presence
of the Standard Model Higgs boson with a 115 GeV mass.
The dark (light) shaded bands indicate the 68\% (95\%) probability
intervals centred on 0.5,
the median expectation in the absence of a signal, which is indicated with
a dot-dashed line.
(b) Upper limits on the signal counts
at the 95\% confidence level ($n_{95}$), as observed (solid line) 
and the expected median (dot-dashed line) for background-only experiments,
as a function of the Higgs boson test mass.
The expected rate of the accepted signal counts 
for a Standard Model Higgs boson with a mass equal to the test mass
is shown with the dotted line.
The shaded bands are the 68\% and 95\% probability intervals
centred on the median background
expectation.  The range for the test mass \mH\ is chosen in both (a) and (b)
to extend to 85~GeV to show the consistency of the 1999 and 2000
OPAL data with the background expectations near the \Zo\ peak, even though previous
OPAL search results~\protect\cite{pr189} are sensitive to test masses below 100~GeV.
}
\end{figure}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\newpage

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Evolution Plot %%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{figure}[ht]
\vspace*{-0.5cm}
\centerline{
\epsfig{file=pr329_06a.eps,width=0.55\textwidth}\epsfig{file=pr329_06b.eps,width=0.55\textwidth}
}
\vspace*{-0.5cm}
\centerline{
\epsfig{file=pr329_06c.eps,width=0.55\textwidth}\epsfig{file=pr329_06d.eps,width=0.55\textwidth}
}
\vspace*{-0.1cm}
\caption[]{\label{fig:sm_evolution}\sl 
The $\ln(1+s/b)$ distributions as a function of the Higgs boson test mass 
for each candidate collected in 1999 and 2000 for
(a) the four-jet channel, (b) the missing-energy channel, (c) the
tau channels, and (d) the electron and muon channels.
Each curve in the plots represents the $\ln(1+s/b)$ of each candidate 
as a function of the Higgs boson test mass. 
The dotted lines %in plots show the $\ln(1+s/b)$ 
show the contributions of the candidates listed in Table~\ref{tab:4j-cand}.
}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\newpage

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{figure}[ht]
\vspace*{-1cm}
\centerline{
\epsfig{file=pr329_08a.eps,width=0.53\textwidth}\epsfig{file=pr329_08b.eps,width=0.6\textwidth}
}
\vspace*{-0.1cm}
\caption{\label{fig:minus2lnq}\sl
(a) The log-likelihood ratio $-2\ln Q$ 
comparing the relative consistency of the data
with the signal+background hypothesis and the 
background-only hypothesis, as a function of the test mass \mH. 
The observation for the data 
is shown with a solid line. 
The dashed line indicates the median background expectation and
the dark (light) shaded band shows the 68\% (95\%) probability
intervals centred on the median.
The median expectation in the presence of a signal
is shown with a dot-dashed line where the hypothesized signal mass is
the test mass.
(b) The $-2 \ln Q$ distribution expected in 
a large number of fictitious background-only 
experiments (solid histogram), and in a large number of
fictitious experiments in the presence of a 115~GeV Higgs
boson (dashed histogram).  The observation
in the data is shown with a vertical solid line.
}
\end{figure}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\end{document}

hep-ex0101014.extracted_bib
\begin{thebibliography}{99}
%
\bibitem{sm}
S.~Glashow, Nucl.~Phys.~{\bf 22} (1961) 579;\\
S.~Weinberg, Phys.~Rev.~Lett.~{\bf 19} (1967) 1264;\\
A.~Salam, ed. N.~Svartholm, {\it Elementary Particle Theory}, 
Almquist and Wiksells, Stockholm (1968) 367.
%
\bibitem{higgs}
P.W.~Higgs, Phys.~Lett.~{\bf 12} (1964) 132;\\
F.~Englert and R.~Brout, Phys.~Rev.~Lett.~{\bf 13} (1964) 321;\\
G.S.~Guralnik, C.R.~Hagen, and T.W.B.~Kibble,
Phys.~Rev.~Lett.~{\bf 13} (1964) 585.
%
\bibitem{higgs_piktalk} 
P.~Igo-Kemenes, presentation given to
the LEP Experiments Committee open session, 
\mbox{\tt http://lephiggs.web.cern.ch/LEPHIGGS/talks/index.html},
3~November 2000.
%
\bibitem{higgs_otherlep}
ALEPH Collaboration, R.~Barate \etal, Phys.~Lett.~{\bf B495} (2000) 1;\\  
L3 Collaboration, M. Acciarri \etal, Phys.~Lett.~{\bf B495} (2000) 18.
\bibitem{pr189} 
OPAL Collaboration, G.~Abbiendi \etal, Eur.~Phys.~J.~{\bf C12} (2000) 567.
%
\bibitem{prold} 
OPAL Collaboration, G. Abbiendi \etal, Eur. Phys. J. {\bf C7} (1999) 407;\\
OPAL Collaboration, K. Ackerstaff \etal, Eur. Phys. J. {\bf C1} (1998) 425.
%
\bibitem{detector}
OPAL Collaboration, K.~Ahmet \etal, Nucl. Instr. and Meth. 
{\bf A305} (1991) 275;\\
S. Anderson {\it et al.}, Nucl. Instr. and Meth. A403 (1998) 326;\\
B.E.~Anderson {\it et al.}, IEEE Trans. on Nucl. Science 41 (1994) 845;\\
G.~Aguillion {\it et al.}, Nucl. Instr. and Meth. A417 (1998) 266.
%
\bibitem{HZHA3} 
P.~Janot \etal, in {\em Physics at LEP2,} edited by G.~Altarelli, 
T.~Sj\"ostrand and F.~Zwirner, CERN 96-01 Vol.~2, 309. \\
For HZHA3 and HZHA2, 
see {\em http://alephwww.cern.ch/$\sim$janot/Generators.html}.
%
\bibitem{CEEX}
S.~Jadach, B.F.~Ward and Z.~Was, Phys.~Lett.~{\bf B449} (1999) 97.
%
\bibitem{grc4f}
J. Fujimoto \etal, Comp. Phys. Comm. {\bf 100} (1997) 128;\\
{\it Physics at LEP2}, J.~Fujimoto \etal, CERN 96-01, Vol.~2, 30.
%
\bibitem{pythia}
T. Sj\"ostrand, Comp. Phys. Comm. {\bf 82} (1994) 74;\\
T. Sj\"ostrand \etal, {\em High-Energy-Physics Event Generation
with PYTHIA 6.1}, hep-ph/0010017 (2000), to be published in
Comp. Phys. Comm.
%
\bibitem{opaltune}
OPAL Collaboration, G. Alexander \etal, Z. Phys {\bf C69} (1996) 543.
%
\bibitem{gopal}
J. Allison \etal, Nucl. Instr. and Meth. {\bf A317} (1992) 47.
%
\bibitem{ref:wwxs} 
OPAL Collaboration, G.~Abbiendi \etal, Phys.~Lett.~{\bf B493} (2000) 249.
%
\bibitem{koralW} 
M.~Skrzypek \etal, \CPC{94} (1996) 216;\\
M.~Skrzypek \etal, \PhysLettB{372} (1996) 289. 
%
\bibitem{ref:4funcertainty}  
M.W.~Gr\"unewald and G.~Passarino \etal,
{\it Four-Fermion Production in Electron-Positron Collisions}, 
{\tt hep-ph/0005309} (2000).
%
\bibitem{LEPEWWG} ALEPH, DELPHI, L3, OPAL Collaborations and the LEP Electroweak
Working Group and the SLD Heavy Flavour and Electroweak Groups, 
{\it  A Combination of Preliminary Electroweak Measurements and Constraints
on the Standard Model}, CERN-EP/2000-016 (2000), and references therein.
%
%\bibitem{LEPHFEWWG} 
%LEP Heavy Flavour Electroweak Working Group, 
%{\it Input Parameters for the LEP Electroweak Heavy Flavour Results 
%for Summer 1998 Conferences}, 
%LEPHF/98-01 (1998).
%
\bibitem{gqq-spl}
E. Norrbin and T. Sj\"ostrand, 
{\em QCD Radiation off Heavy Particles}, 
{\tt hep-ph/0010012} (2000).
\bibitem{WWpaper}
OPAL Collaboration, G.~Abbiendi \etal, 
{\em Measurement of the Mass and Width of the W Boson in 
${\mathrm{e^+e^-}}$ Collisions at 189 GeV}, 
CERN-EP-2000-099, submitted to Phys. Lett. B.
%
\bibitem{bib:kendallstuartord} 
A.~Stuart and J.~K.~Ord, 
{\it Kendall's Advanced Theory of Statistics}, Vol.~2, Ch.~23
5th Ed., Oxford University Press, New York, (1991).
%
\bibitem{LEPHIGGS202} 
ALEPH, DELPHI, L3, OPAL Collaborations, and
the LEP working group for Higgs boson searches,
{\em Search for Higgs bosons: Preliminary combined results using LEP data 
collected at energies up to 202 GeV,} 
CERN-EP/2000-055 (2000)
%
%\bibitem{pb-method} 
%LEP working group for Higgs boson searches, CERN/LEPC 97-11;\\
%P.~Bock, HD-PY-96/05 (1996).
%
\bibitem{ref:cousins} 
R.D.~Cousins and V.L.~Highland, Nucl.~Instr.~and~Meth. {\bf A320} (1992) 331.
%
\bibitem{LEPHIGGS00COMB} ALEPH, DELPHI, L3 and OPAL Collaborations, and the
LEP Higgs Working Group, in preparation.
%
\end{thebibliography}