Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Perturbative QCD and Power Corrected Hadron Spectra and Spectral Moments
  in the Decays $B \to X_s \ell^+ \ell^-$   Leading order (in $\alpha_s$) perturbative QCD and power ($1/m_b^2)$
corrections to the hadronic invariant mass and hadron energy spectra in the
decay $B \to X_s \ell^+ \ell^-$ are reviewed in the standard model using the
heavy quark expansion technique (HQET). In particular, the first two hadronic
moments $<S_H^n>$ and $<E_H^n>$, $n=1,2$, are presented working out their
sensitivity on the HQET parameters $\lambda_1$ and $\bar{\Lambda}$. Data from
the forthcoming B facilities can be used to measure the short-distance
contribution in $B \to X_s \ell^+ \ell^-$ and determine the HQET parameters
from the moments $<S_H^n>$. This could be combined with complementary
constraints from the decay $B \to X \ell \nu_\ell$ to determine these
parameters precisely.

15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph