Related papers: Precise predictions for B -> Xc tau nu decay distr…
We study the Lambda_QCD/M_B corrections from subleading shape functions in inclusive B-meson decays. We propose a natural and smooth interpolation from the endpoint region to the full phase space, and derive expressions for the triple…
We have studied the one meson radiative tau decays: tau- -> nu(tau) pi-(K-) gamma, computing the structure dependent contributions within a Lagrangian approach based on the large-N(C) limit of QCD that ensures the proper low-energy limit…
Analytic formulae for the one-loop order QCD corrections to the differential width of the semileptonic b decay are given with the tau polarization taken into account. Thence the polarization of tau is expressed by its energy and the…
Using a known result by Falk et al. for the 1/m_b^2 correction to the dilepton invariant mass spectrum in the decay B \rightarrow X_s \mu^+ \mu^-, we calculate the 1/m_b^2 correction to the left-right muon polarization asymmetry in this…
Theoretical predictions for B decay rates are rewritten in terms of the Upsilon(1S) meson mass instead of the b quark mass, using a modified perturbation expansion. The theoretical consistency of this expansion is shown both at low and high…
We discuss a novel approach to systematically determine the long-distance contribution to $B\to K^*\ell\ell$ decays in the kinematic region where the dilepton invariant mass is below the open charm threshold. This approach provides the most…
It is argued that the dominant subleading shape-function contributions to the endpoint region of the charged-lepton energy spectrum in B -> X_u l nu decays can be related in a model-independent way to an integral over the B -> X_s gamma…
B physics has played a prominent role in investigations of new physics effects at low-energies. Presently, the largest discrepancy between a standard model prediction and experimental measurements appears in the branching ratio of the…
Phenomenological models of heavy flavour decays differ significantly in their predictions of global features of $B_c$ decays, like the $B_c$ lifetime or the relative weight of $c\ra s$ and $b\ra c$ transitions. The $1/m_Q$ expansion which…
The next-to-next-to-leading order perturbative QCD corrections to R_tau and the higher moments of the invariant mass distribution in the hadronic tau decays are considered. The renormalization scheme dependence of these corrections is…
The contributions of subleading shape functions to inclusive decay distributions of B mesons are derived from a systematic two-step matching of QCD current correlators onto soft-collinear and heavy-quark effective theory. At tree-level, the…
Experimental studies of B -> D^(*) tau nu decays, are reported. The results are based on large data samples collected at the Upsilon(4S) resonance with the Belle detector at KEKB and the BABAR detector at the SLAC PEP-II asymmetric energy…
We test whether or not the tau lepton manifests the same couplings as the mu lepton by investigating the relative decay rates in purely leptonic D+ meson decays. Specifically, we place the first upper limit on the ratio R=Gamma(D+ -> tau+…
We study the O(Lambda/mb) corrections to the singly and doubly differential hadronic invariant mass spectra d\Gamma/dsH and d\Gamma/dsH dq^2 in b -> u decays, and discuss the implications for the extraction of the CKM matrix element |Vub|.…
We examine in detail the semi-leptonic decay $\Lambda_b \to \Lambda_c \tau{\bar \nu}_{\tau}$, which may confirm previous hints, from the analogous $B$ decay, of a new physics beyond the standard model. First of all, starting from rather…
Exclusive semileptonic B decays into $D_1$ and $D_2^*$ mesons are investigated including order $\Lambda_{QCD}/m_{c,b}$ corrections using the heavy quark effective theory. At zero recoil, the $\Lambda_{QCD}/m_{c,b}$ corrections can be…
We present updated and comprehensive Standard Model predictions for the inclusive rare decay $B \to X_s \nu\bar{\nu}$. Using a state-of-the-art determination of the short-distance coefficient, including NLO QCD and electroweak effects, and…
We calculate general moments of the lepton energy spectrum in inclusive semileptonic B -> X_c l \nu decay. Moments which allow the determination of mb^{1S} and lambda1 with theoretical uncertainties Delta(mb^{1S}) ~ 0.04 GeV and…
Neutral-current semileptonic $B$ decays are plagued by hadronic resonances across the dilepton invariant-mass squared spectrum, $q^2$. For light leptons, $\ell=e,\mu$, these resonances can be avoided with suitable $q^2$ cuts. This strategy…
We present a concise review of the recent theoretical progress concerning the standard model calculation of the inclusive radiative Bbar -> X_s gamma decay. Particular attention is thereby devoted to the calculations of the…