Hadron spectra and spectral moments in the decayB→Xsl+l−using HQET

Abstract

We compute the leading order (in ${\ensuremath{\alpha}}_{s})$ perturbative QCD and power ${(1/m}_{b}^{2})$ corrections to the hadronic invariant mass and hadron energy spectra in the decay $\stackrel{\ensuremath{\rightarrow}}{B}{X}_{s}{l}^{+}{l}^{\ensuremath{-}}$ in standard model using the heavy quark expansion technique (HQET). Results for the first two hadronic moments $〈{S}_{H}^{n}〉$ and $〈{E}_{H}^{n}〉,$ $n=1,2,$ are presented here working out their sensitivity on the HQET parameters ${\ensuremath{\lambda}}_{1}$ and $\overline{\ensuremath{\Lambda}}.$ Data from the forthcoming B facilities can be used to measure the short-distance contribution in $\stackrel{\ensuremath{\rightarrow}}{B}{X}_{s}{l}^{+}{l}^{\ensuremath{-}}$ and determine the HQET parameters from the moments $〈{S}_{H}^{n}〉.$ This can be combined with the analysis of semileptonic decays $\stackrel{\ensuremath{\rightarrow}}{B}\mathrm{Xl}{\ensuremath{\nu}}_{l}$ to determine them precisely.