Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Attempts at Explaining the NuTeV Observation of Di-Muon Events   The NuTeV Collaboration has observed an excess in their di-muon channel,
possibly corresponding to a long-lived neutral particle with only weak
interactions and which decays to muon pairs. We show that this can {\it not} be
explained by pair production of neutralinos in the target followed by their
decay far downstream in the detector via a $LLE$ R-parity violating (RPV)
operator, as suggested in the literature. In the parameter region allowed by
LEP the event rate is far too small. We propose instead a new neutralino
production method via $B$-mesons, which can fully explain the observation. This
is analogous to neutrino production via $\pi$-mesons. This model can be
completely tested and thus also possibly excluded with NOMAD data. If it is
excluded, the NuTeV observation is most likely not due to physics beyond the
Standard Model. Our model can also be tested at the current and future
$B$-factories. This opens up a new way of testing a long-lived neutralino LSP
at fixed-target experiments and thus a possibility to close the gap between
collider and cosmological tests of R-parity violation. We also discuss a
possible explanation in terms of a neutral heavy lepton mixing with the
Standard Model neutrinos. The flavour structure of the observation can be
accounted for but the production rate is far too low.

25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph