Related papers: Threshold Resummation in B --> X_c l nu_l Decays
We propose a method to non-perturbatively calculate the forward-scattering matrix elements relevant to inclusive semi-leptonic B meson decays. Corresponding hadronic structure functions at unphysical kinematics are accessible through…
We propose a method for a QCD based calculation of one-particle inclusive decays of the form B \to \bar D X or B \to \bar D^* X. It is based on the heavy mass limit and a short distance expansion of the amplitudes, which yield a power…
Motivated by recent experimental results we reconsider semileptonic D to P l nu_l and D to V l nu_l decays within a model which combines heavy quark symmetry and properties of the chiral Lagrangian. Using limits of soft collinear effective…
We evaluate the three-loop matching conditions for the dimension-five operators that are relevant for the b -> s gamma decay. Our calculation completes the first out of three steps (matching, mixing and matrix elements) that are necessary…
In spite of undeniable similarities of the applied techniques, somewhat different challenges are encountered when extracting, from QCD sum rules derived from two-point correlators of appropriate interpolating heavy-light quark currents, the…
We compute non-perturbative contributions to b->s l+ l- that are not explicitly suppressed by powers of the b-quark mass. They are proportional to lambda_2 and arise from an interference between the free-quark amplitude and higher order…
In these lectures, I present several important applications of QCD sum rules to the decay processes involving heavy-flavour hadrons. The first lecture is introductory. As a study case, the sum rules for decay constants of the heavy-light…
We calculate, for the first time using unquenched lattice QCD, form factors for the rare decay B -> Kll in and beyond the Standard Model. Our lattice QCD calculation utilizes a nonrelativistic QCD formulation for the b valence quarks, the…
QCD sum rules on the light-cone are derived for the sum $f^+ + f^-$ of the $B\to \pi$ and $D\to \pi$ form factors taking into account contributions up to twist four. Combining the results with the corresponding $f^+$ form factors calculated…
We calculate the two-loop QCD correction to the form factors of on-shell b-quark decay to an energetic massless quark, which constitutes the last missing piece required for an O(alpha_s^2) determination of |V_ub| from inclusive…
We revisit QCD calculations of radiative heavy meson decay form factors by including the subleading power corrections from the twist-two photon distribution amplitude at next-to-leading-order in $\alpha_s$ with the method of the light-cone…
We verify to order alpha_s^4 two previously conjectured relations, valid in four dimensions, between constant terms in threshold resummation (for Deep Inelastic Scattering and the Drell-Yan process) and the second logarithmic derivative of…
We investigate the form factors of $B_c$ meson into $S$-wave charmonium within the nonrelativistic QCD effective theory and obtain the next-to-leading order relativistic corrections to the form factors, where both the $B_c$ meson and the…
Lattice calculation of $B\to D^{(*)}\ell\bar\nu$ decay form factors is now available from multiple lattice collaborations for both zero-recoil limit and non-zero recoil kinematics. Yet, there are a number of challenges we face to better…
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…
In this paper we calculate the weak form factors of the decays $B_c(B)\to Dl\tilde\nu$ by using the chiral current correlator within the framework of the QCD light-cone sum rules (LCSR). The expressions of the form factors only depend on…
Using the most general form of the interpolating current of the heavy spin 1/2, $\Sigma_{b}$ baryon and distribution amplitudes of the nucleon, the transition form factors of the semileptonic $\Sigma_{b}\to Nl\nu$ decay are calculated in…
We revisit QCD factorization of $B\to \pi\pi$ form factors at large dipion masses, by deriving new constraints based on the analyticity properties of these objects. We then propose a parametrization of the form factors, inspired by the…
I derive an all-order resummation formula for the logarithmically enhanced contributions proportional to $\frac{\alpha_s^n}{x \pm \xi} \log (\frac{\xi \pm x}{2\xi})^k$ in the quark coefficient function of deeply-virtual-Compton scattering…
The inclusive decay B --> X_u l nu is of much interest because of its potential to constrain the CKM element |V_ub|. Experimental cuts required to suppress charm background restrict measurements of this decay to the shape-function region,…