Related papers: Two-loop evolution equation for the B-meson distri…
We calculate the one-loop QCD corrections for the decay of an off-shell vector boson with vector couplings into two pairs of quarks of equal or unequal flavours keeping all orders in the number of colours. These matrix elements are relevant…
The radiative corrections to the pure leptonic decay $B_c \to \ell\nu_{\ell}$ up-to one-loop order is presented. How to cancel the infrared divergences appearing in the loop calculations, and the radiative decay $B_c \to…
Evolution of structure functions and their moments at low and moderate $Q^2$ is studied in the chiral field theory. Evolution equations based on perturbation expansion in the coupling constant of the effective theory are derived and solved…
The two-body hadronic decays of B mesons into pseudoscalar and axial vector mesons are studied within the framework of QCD factorization. The light-cone distribution amplitudes (LCDAs) for $^3P_1$ and $^1P_1$ axial-vector mesons have been…
Recently, we have derived light-cone sum rules for exclusive B-meson decays into light energetic hadrons from correlation functions within soft-collinear effective theory. In these sum rules the short-distance scale refers to…
We present a small x resummation for the GLAP anomalous dimension and its corresponding dual BFKL kernel, which includes all the available perturbative information and nonperturbative constraints. Specifically, it includes all the…
A main feature of high-energy scattering in QCD is saturation in the number density of gluons. This phenomenon is described by non-linear evolution equations, JIMWLK and BK, which have been derived at leading logarithmic accuracy. In this…
We calculate the complete ${\cal O}(\alpha_s)$ corrections to the quark decay $b\to ccs$ taking full account of the quark masses, but neglecting penguin contributions. For a c to the b quark mass ratio $m_c/m_b= 0.3$ and a strange quark…
We present a new method for solving the BFKL evolution applicable at both leading and next-to-leading logarithmic accuracy, and tailored to the study of QCD multi-jet events at colliders. We utilise this to discuss corrections to the…
We derive the evolution equation for the second order curvature perturbation using standard techniques of cosmological perturbation theory. We do this for different definitions of the gauge invariant curvature perturbation, arising from…
We derive a QCD sum rule for the inverse moment of the $B_s$-meson light-cone distribution amplitude in HQET. Within this method, the $SU(3)_{fl}$ symmetry violation is traced to the strange quark mass and to the difference between strange…
We compute the complete set of two-loop beam functions for the transverse momentum distribution of the leading jet produced in association with an arbitrary colour-singlet system. Our results constitute the last missing ingredient for the…
We report on recent progress on perturbative QCD calculations of certain exclusive rare weak $B$ meson decays involving hard photons. In the limit of a photon energy $E_\gamma$ much larger than $\Lambda_{QCD}$, the amplitudes for such…
We extract the B, D, and D* meson wave functions from the CLEO data of the decays B -> K*\gamma and B -> D^(*)\pi in the perturbative QCD framework. In this formalism, various logarithmic corrections are organized to give the Wilson…
A shape-function independent relation is derived between the partial B->X_u+l+nu decay rate with a cut on P_+=E_X-P_X<Delta and a weighted integral over the normalized B->X_s+gamma photon-energy spectrum. The leading-power contribution to…
Starting from a master equation, we derive the evolution equation for the size distribution of elements in an evolving system, where each element can grow, divide into two, and produce new elements. We then probe general solutions of the…
The computation of direct CP asymmetries in charmless B decays at next-to-next-to-leading order (NNLO) in QCD is of interest to ascertain the short-distance contribution. Here we compute the two-loop penguin contractions of the…
General analyses of $B$-physics processes beyond the Standard Model require accounting for operator mixing in the renormalization-group evolution from the matching scale down to the typical scale of $B$ physics. For this purpose the…
We construct a factorization theorem that allows to systematically include QCD corrections to the contribution of the electromagnetic dipole operator in the effective weak Hamiltonian to the $\bar B_s \to \mu^+\mu^-$ decay amplitude. We…
We consider evolution equations describing the scale dependence of the wave function of a baryon containing an infinitely heavy quark and a pair of light quarks at small transverse separations, which is the QCD analogue of the helium…