The rate of semitauonic B decays has been consistently above theory expectations since these decays were first measured. Recently significant differences between the forward-backward asymmetry in B -> Denu and B -> Dmunu were also reported. Belle II data are well suited to probe these anomalies. The low-background collision environment along with the possibility of partially or fully...
We present analytical results for higher order corrections to the decay spectrum of inclusive semileptonic heavy hadron weak decays using the heavy quark expansion (HQE). We describe the analytical computation of the spectrum of the leptonic invariant mass for $B \rightarrow X_c \ell \bar{\nu}$ up to terms of order $1/m_b^3$ within the HQE at next-to-leading order (NLO) in $\alpha_s$. The full...
I will describe the first results of a new method to compute inclusive semileptonic decays on the lattice and the future perspectives.
QCD light-cone sum rules (LCSRs) are a method to calculate the relevant hadronic matrix elements in exclusive $b$-quark decays. I focus on the LCSRs with $B$ or $\Lambda_b$ distribution amplitudes. The versatility of this method allows to apply it to a wide variety of decays, especially to those where lattice QCD calculations are not available yet.
In this spirit, I present a first...
The CKM matrix element $V_{ub}$ is both the smallest and least known of all CKM matrix elements; its current value has been determined in many ways, but directly primarily through the exclusive process $B\to\pi\ell\nu$. In this talk, we will present our progress towards a lattice QCD determination of the $V_{ub}$ matrix element from a novel transition - $B\to \rho \ell \nu$. On this ensemble,...
We discuss the Lorentz decomposition of $B \to \gamma^*$ matrix elements in terms of hadronic form factors, which are needed for a theory description of $B^- \to \ell^- \bar{\nu}_\ell \ell' \bar{\ell'}$ decays.
Our approach closely follows the Bardeen–Tung–Tarach procedure and ensures freedom from kinematic singularities, which is needed to apply dispersion relations in the photon momentum....
Lattice QCD computations of a number of physical quantities, including leptonic decay rates, yield sufficiently precise results that electromagnetic corrections need to be implemented to make further progress in determining the parameters of the Standard Model and checking consistency with the corresponding experimental results. After a brief introduction to the framework, I will present the...
In this talk I will report on the calculation of NNLO QCD corrections to the
flavor observables in the mixing of neutral $B$ mesons and discuss their
numerical impact. The physical relevance of this work stems from the fact
that experimental measurements of e.g. the flavor mixing parameter
$\Delta \Gamma_{12}^s$ have already achieved per cent level accuracy,
while theoretical predictions...
