Inclusive semileptonic B → Xc l ν̄ decay offers the opportunity to measure the CKM parameter |Vcb| and the bottom quark mass from experiment. . Experimental studies of moments of the differential decay spectra of B → Xc l ν̄ , combined with a measurement of the total inclusive decay rate, allow the extraction of these parameters to occur with high precision. The idea is that sufficiently inclusiv...

The observed inclusive decay of B–mesons into η′ + X is interpreted as the consequence of the gluonic decay of the b–quark into an s–quark. As a result of the QCD anomaly this decay proceeds partly as the decay b → s + η′, similar to b → s + J/ψ. The hadronic recoiling system is found to have a relatively large mass. Analogously one expects a decay of the type b→ s+ σ. The branching ratios for ...

The differential decay spectrum dΓ/dEedq 2 for the semileptonic decay of an unpolarized hadron containing a b-quark, and the decay spectrum dΓ/dEedq dcos θ for polarized Λb decay are computed to second order in the 1/mb expansion. Most of the 1/m 2 b corrections have a simple physical interpretation, which is discussed in detail. The implications of the results for the determination of Vub are ...

The ACCMM model predicts the lepton spectrum from B meson decay by assuming the meson disintegrates into a spectator quark of definite mass and momentum distribution and an off shell b quark whose decay leptons (boosted into the rest frame of the meson) determine the lepton spectrum. In this letter, we show that one can define a model dependent b quark mass so that the spectrum derived from the...

We probe the top-quark electric dipole moment (EDM) in top-quark pair production via photon-photon fusion at a photon linear collider. We show how linearly-polarized photon beams can be used to extract information on the topquark EDM without the use of complicated angular correlations of top-quark decay products. If the luminosity of the laser back-scattered photon-photon collisions is comparab...

We compute the nonleptonic weak decay width of a heavy-light meson in 1+1 spacetime dimensions with a large number of QCD colors (the ’t Hooft model) as a function of the heavy quark mass. In this limit, QCD is exactly soluble, and decay modes are dominated by two-particle final states. We compare the results to the tree-level partonic decay width of the heavy quark in order to test quark-hadro...

In the heavy quark limit, the inclusive decay rate of weakly decaying heavy hadron (HQ) can be expressed in an expansion of the weak matrix elements in powers of 1/mQ, where mQ is the heavy quark mass . (In this article, though we discuss generally for a heavy system, b or c but quantitatively refer only to beauty case). At the leading order, the hadronic decay rate is given by the free heavy q...

O(α s) radiative corrections to polarized top decay into a charged Higgs t(↑) → H + + b Abstract We calculate the O(α s) radiative corrections to polarized top quark decay into a charged Higgs and a bottom quark in Two-Higgs-Doublet-Models for nonzero bottom quark masses m b = 0. The radiative corrections to the polarization asymmetry parameter of the decay can become as large as 25 %. We provi...

We set up sum rules for heavy lambda decays in a full QCD calculation which in the heavy quark mass limit incorporates the symmetries of heavy quark effective theory. For the semileptonic Λ c decay we obtain a reasonable agreement with experiment. For the Λ b semileptonic decay we find at the zero recoil point a violation of the heavy quark symmetry of about 20%.

We determine the constraints on the anomalous top-quark coupling associated with the flavor-changing neutral current vertex t̄cγ from the limits on the b-quark rare decay b → sγ and non-standard top-quark decays. Based on these constraints, we discuss the experimental observability of the rare decay mode t → cγ, both at the Fermilab Tevatron with a luminosity-upgrade and at the LHC.