We review recent experimental and theoretical developments in inclusive semileptonic B -> Xc l nu decays. In particular, we discuss the determination of |Vcb| and of the heavy quark masses through fits based on the Operator Product Expansion.
This paper summarizes the relevant theoretical developments, outlines some ideas to improve experimental searches for free neutron-antineutron oscillations, and suggests avenues for future improvement in the experimental sensitivity.
We perform global fits to the moments of semileptonic B decay distributions and extract |V_cb|, the heavy quark masses, and the non-perturbative parameters of the heavy quark expansion. We include NNLO perturbative corrections and recent determinations of the charm mass, and discuss how they improve the precision of the global fit. In particular, using the m_c determination of Ref.[11] we get m_b^kin=4.541(23) GeV and |V_cb|=(42.42+- 0.86) 10^{-3}. We also discuss the implications of the new fits for the normalization of rare B decays, the zero-recoil sum rule in B-> D* l nu, and the inclusive determination of |V_ub|.
Leptonic and semileptonic decays in the charm sector have been well studied in recent years. With the largest data sample near $Dbar D$ threshold, precision measurements of leptonic and semileptonic decays of charm meson and baryon are perfromed at BESIII. Test for letpon flavor universality is also performed. Sensitivity for rare leptonic and semileptonic charm decays is significantly improved taking advantage of the huge statistics in LHCb and the $B$ factories.
The present status of our knowledge of the magnitude of the quark mixing parameter Vcb is reviewed, with particular emphasis on the factors affecting experimental and theoretical errors and on prospects for a more precise determination.
We present an analysis of the semi-inclusive decays $B_s to D_s^- X ell^+ u$ and $B_s to D_s^{*-} X ell^+ u$, where $X$ denotes a final state that may consist of additional hadrons or photons and $ell$ is an electron or muon. The studied $B_s$ decays are contained in the $121.4~{rm fb}^{-1}$ $Upsilon(5S)$ data sample collected by the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. The branching fractions of the decays are measured to be $mathcal{B}(B_s to D_s^- X ell^+ u) = [8.2 pm 0.2 (text{stat}) pm 0.6 (text{syst}) pm 1.4 (text{ext})]%$ and $mathcal{B}(B_s to D_s^{*-} X ell^+ u) = [5.4 pm 0.4 (text{stat}) pm 0.4 (text{syst}) pm 0.9 (text{ext})]%$, where the first two uncertainties are statistical and systematic and the last is due to external parameters. The measurement also provides an estimate of the $B_s^{(*)}bar{B}_s^{(*)}$ production cross-section, $sigma(e^+e^- to B_s^{(*)}bar{B}_s^{(*)}) = (53.8 pm 1.4 (text{stat}) pm 4.0 (text{syst}) pm 3.4 (text{ext})),{rm pb}$, at the center-of-mass energy $sqrt{s} = 10.86,{rm GeV}$.
Paolo Gambino
,Christoph Schwanda
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(2011)
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"Theoretical and Experimental Status of Inclusive Semileptonic Decays and Fits for |Vcb|"
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Christoph Schwanda
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