Related papers: One-loop QCD corrected distribution in B to X+elec…
Manifestly Lorentz-invariant baryon chiral perturbation theory is used to calculate the radiative correction of low energy elastic lepton proton scatterings. Corrections of differential cross section and charge asymmetry are given at chiral…
Nonperturbative corrections up to $m_b^{-2}$ to the heavy lepton energy distributions are investigated in the inclusive semileptonic weak decays of heavy flavors in QCD. In the case of $B$-meson decays, for $b \ra u\tau\bnu$ transitions…
Infrared divergences of QCD scattering amplitudes can be derived from an anomalous dimension matrix, which is also an essential ingredient for the resummation of large logarithms due to soft gluon emissions. We report a recent analytical…
We calculate and discuss the one-loop corrections to the photon sector of QED interacting to a background gravitational field. At high energies the fermion field can be taken as massless and the quantum terms can be obtained by integrating…
We calculate the imaginary part of the retarded two-loop self-energy of a static vector boson in a plasma of quarks and gluons of temperature T, using the imaginary time formalism. We recombine various cuts of the self-energy to generate…
We study the transverse-momentum distribution of hadrons produced in semi-inclusive deep-inelastic scattering. We consider cross sections for various combinations of the polarizations of the initial lepton and nucleon or the produced…
Results are presented for the leading power-suppressed (1/Q) contributions to shape variables in deep inelastic lepton scattering. These are then combined with available leading order perturbative estimates.
The QCD one-loop renormalization is restudied in a mass-dependent subtraction scheme in which the quark mass is not set to vanish and the renormalization point is chosen to be an arbitrary timelike momentum. The correctness of the…
Within the framework of nonrelativistic QCD (NRQCD) factorization, we compute the three-loop QCD corrections to the decay constant of $B_c$. We reconstruct the analytical expressions for the three-loop renormalization constant and the…
We review techniques for more efficient computation of perturbative scattering amplitudes in gauge theory, in particular tree and one-loop multi-parton amplitudes in QCD. We emphasize the advantages of (1) using color and helicity…
This talk brings attention to what is knowable from perturbative QCD theory on two-parton distribution functions in the light of CDF measuruments of the inclusive cross section for double parton scattering.
In this paper we present chiral extrapolation formulas for the generalized form factors connected to the first moments of chiral-even generalized parton distributions. For the description of QCD at low energies we employ the framework of…
A brief report on the QCD factorization approach to exclusive B decays and its applications is presented. In an appendix a subtle issue concerning partial integration in the parameterization of infrared-sensitive power corrections is…
The form factor that yields the light-by-light scattering contribution to the muon anomalous magnetic moment is computed in lattice QCD+QED and QED. A non-perturbative treatment of QED is used and is checked against perturbation theory. The…
The production of lepton pairs at low invariant mass and finite transverse momentum resolves QCD dynamics at the boundary between the perturbative and non-perturbative domains. We investigate the impact of NNLO QCD corrections on these…
We demonstrate a factorization formula for semi-inclusive deep-inelastic scattering with hadrons in the current fragmentation region detected at low transverse momentum. To facilitate the factorization, we introduce the transverse-momentum…
We discuss exclusive charmless B decays within the Standard Model of particle physics. In particular, we consider hadronic two-body decays as B -> pi pi and perform a conceptual analysis of heavy-to-light form factors which encode the…
We present results at one-loop order of perturbation theory for various improvement coefficients in on-shell O($a$) improved lattice QCD. In particular we determine the additive counterterm required for on-shell improvement of the isovector…
We present the O(alpha_s^4) virtual QCD corrections to gluon-gluon scattering due to the interference of tree and two-loop amplitudes. We work in conventional dimensional regularisation and give analytic expressions renormalised in the…
We propose a theoretical framework for analyzing three-body hadronic $B$ meson decays based on the perturbative QCD approach. The crucial nonperturbative input is a two-hadron distribution amplitude for final states, whose involved…