Related papers: Three-Scale Factorization Theorem and Effective Fi…
The renormalon calculus is used to calculate the terms of order $\beta_0^{n-1}\alpha_s^n$ in the perturbative expansions of the Wilson coefficients and hard-scattering kernels entering the QCD factorization formula for hadronic B-meson…
In this paper, we studied the charmless $B_{c}\to VV$ ($V$ denotes the light ground $\rm SU(3)$ vector meson) decays within the framework of QCD factorization. In the evaluation, two different schemes for regulating the end-point divergence…
We calculate next to leading order QCD corrections to the direct decays b -> J/Psi + X and b -> eta_c + X. The strong renormalization scale dependence is seen to persist also in this order and in fact the rate is driven to an unphysical…
In this work, based on the assumption of two-quark structure of the scalars, the charmless hadronic $B_c \to SP, SV$ decays(here, $S$, $P$, and $V$ denote the light scalar, pseudoscalar, and vector mesons, respectively) are investigated by…
We consider two SU(3) breaking parameters, $R_1(m_B)$ and $R_2(m_B)$, appearing in a relation between $B^+\to K\pi$ and $B^+\to\pi\pi$ amplitudes, which plays an important role in determining the weak phase $\gamma$. We identify an…
I summarize results and performance of the dynamical theory of charmless hadronic B decays, based on QCD factorization in the heavy quark limit. On the theoretical side, a number of NNLO (alpha_s^2) amplitudes are now available, all showing…
Building upon the Covariant Derivative Expansion, we develop a method to compute effective actions that is able to capture non-perturbative effects induced by strong background fields. We demonstrate the method in scalar QED, by deriving…
The renormalization-scale dependence of the non-factorizable virtual corrections to Higgs boson production in weak boson fusion at next-to-next-to-leading order in perturbative QCD is unusually strong, due to the peculiar nature of these…
We compute the three-loop QCD corrections to the vertex function for the Yukawa coupling of a Higgs boson to a pair of bottom quarks in the limit of vanishing quark masses. This QCD form factor is a crucial ingredient to third-order QCD…
The rare process of $W$ radiative decay into the $B_c$ meson can serve as an interesting play ground for testing two influential perturbative QCD approaches: non-relativistic quantum chromodynamics (NRQCD) and ligh-cone (LC) factorization.…
In this note we investigate a new type of non-commutative field theory based on a constant skew-symmetric three-form parameter. In 3+1 dimensions such a three-form parameter can be viewed as a short-distance regulator which nevertheless…
We have systematically investigated the semi-inclusive B decays $B\to MX$, which are manifestations of the quark decay $b \to Mq$, within a framework inspired by QCD-improved factorization. These decays are theoretically clean and have…
In pure gauge SU(3) near beta = 6, weak and strong coupling expansions break down and the MC method seems to be the only practical alternative. We discuss the possibility of using a modified version of perturbation theory which relies on a…
These notes provide a pedagogical introduction to the theory of non-leptonic heavy-meson decays recently proposed by Beneke, Buchalla, Sachrajda and myself. We provide a rigorous basis for factorization for a large class of non-leptonic…
We develop perturbative QCD factorization theorems for the exclusive semileptonic heavy baryon decay $\Lambda_b \to pl{\bar\nu}$, in which the relevant hadronic form factor is expressed as the convolution of a hard subamplitude with the…
We perform a systematic study of two-meson form factors of the scalar, vector, and anti-symmetric tensor types within the framework of the $U(3)$ resonance chiral theory. The complete perturbative form factors in both the…
Tree-level $n$-point gauge-theory amplitudes with $n-2k$ gluons and $k$ pairs of (massless or massive) particles in the fundamental (or other) representation of the gauge group are invariant under a set of symmetries that act as…
We address the issue of a consistent power counting scheme in manifestly Lorentz-invariant baryon chiral perturbation theory. We discuss the inclusion of vector mesons in the calculation of the nucleon electromagnetic form factors. We…
We study a Lagrangian formalism that avoids double counting in effective field theories where distinct fields are used to describe different infrared momentum regions for the same particle. The formalism leads to extra subtractions in…
We perform the study of perturbative aspects of a three-dimensional supersymmetric Maxwell-Chern-Simons-Proca theory minimally coupled to scalar superfields. Using the superfield formalism, we derive the propagators for both gauge and…