相关论文: Recent Developments in Bbar -> X_s gamma

We study the decay $\bar B\to X_s\gamma$ in Randall-Sundrum models with an IR-localised bulk Higgs. The two models under consideration are a minimal model as well as a model with a custodial protection mechanism. We include the effects of…

The present NLL prediction for the decay rate of the rare inclusive process $\bar B \to X_s \gamma$ has a large uncertainty due to the charm mass renormalization scheme ambiguity. We estimate that this uncertainty will be reduced by a…

The two--loop ${\cal O}(\alpha_s G_F m_t^2)$ corrections to the $b\bar b$ decay rate of the Standard Model Higgs boson as well as its production via $e^+e^- \to ZH$ will be presented. These QCD corrections are obtained by using a low-energy…

Higgs boson radiative decays of the form $H\rightarrow f\bar{f}\gamma$ are calculated in the Standard Model using the complete one-loop expressions for the decay amplitudes. Contributions to the radiative width from leptons and light quarks…

We report recent progress in SM calculations of $b \to s$ transitions. We discuss the first NNLL prediction of the $\bar B \to X_s \gamma$ branching ratio, including important additional subtleties due to non-perturbative corrections and…

The moments of the photon spectrum in the inclusive $B\to X_s\,\gamma$ decay can be calculated to order $\alpha_s$ accuracy at present, without knowing the $\alpha_s$ corrections to the effective Hamiltonian. We discuss the standard model…

A detailed standard model (SM) calculation of the O(alpha_s) virtual corrections to the decay width for b -> s g is presented (g denotes a gluon). Also the complete expressions for the corresponding bremsstrahlung corrections are given.…

An analytic result for the O(alpha_s corrections to the triple differential B -> X_u l nu decay rate is presented, to leading order in the heavy-quark expansion. This is relevant for computing partially integrated decay distributions with…

The goal of the SIMBA collaboration is to provide a global fit to the available data in inclusive B -> X_s gamma and B -> X_u l nu decays. By performing a global fit one is able to simultaneously determine the relevant normalizations, i.e.…

We calculate the next-to-leading corrections to the branching ratio of exclusive $B\to K^* \gamma$ decay. The renormalization scale dependence is reduced compared to the leading logarithmic result but there remains a dependence on a cutoff…

We study the loop induced rare decays $B_s(B_d)\to\gamma\nu\bar\nu$ within the standard model. Both constituent quark model and pole model are used and the branching ratios turn out to be of the orders of $10^{-8}$ for $B_s\to \gamma \nu…

Recent progress in calculating O(alpha_s^2) corrections to inclusive and exclusive semileptonic b-->c transitions is reviewed. The impact of these corrections on the |V_cb| determination from both inclusive and exclusive B decays is…

The angle gamma of the standard CKM unitarity triangle can be determined from B -> D K decays with a very small irreducible theoretical error, which is only due to second-order electroweak corrections. We study these contributions and…

Using results on soft-collinear factorization for inclusive B-meson decay distributions, a systematic study of the partial B->Xs+gamma decay rate with a cut E_gamma<E_0 on photon energy is performed. For values E_0<1.9 GeV the rate can be…

This paper summarizes current results for rare non-hadronic b decay processes. The world average Br(b -> s gamma)=(3.14 +/-0.48)x10^(-4) is in agreement with the standard model prediction. Upper limits on b-> s l^+ l^- and b -> l^+ l^- are…

The radiative B -> tau^+ tau^- gamma decay is investigated in the framework of the Standard Model. When only short (short and long together) distance contributions are taken into account, the Branching Ratio is found as 9.54x10^(-9)…

The latest Belle and BaBar measurements of the inclusive B -> X_s l^+ l^- branching ratio have smaller errors and lower central values than the previous ones. We point out that these results indicate that the sign of the b -> s gamma…

We calculate the alpha_s virtual corrections to the decay width for b --> s gluon in the standard model. Also the corresponding order alpha_s bremsstrahlung corrections are systematically calculated in this paper. The combined result is…

We give a more complete calculation of $b \to s\gamma $ decay, including leading log QCD corrections from $m_{top}$ to $M_W$ in addition to corrections from $M_{W}$ to $m_b$. We have included the full set of dimension-6 operators and…

We extend previous computations of the second order QCD corrections to semileptonic b \to c inclusive transitions, to the case where the charged lepton in the final state is massive. This allows accurate description of b \to c \tau \bar…