Related papers: Beyond the Narrow-Width Limit for Off-Shell and Bo…
We study excited baryon decay widths in large N_c QCD. It was suggested previously that some spin-flavor mixed-symmetric baryon states have strong couplings of O(N_c^{-1/2}) to nucleons [implying narrow widths of O(1/N_c)], as opposed to…
We consider the resummation of soft-gluon effects in heavy quark to heavy quark decays, namely the processes Q1 -> Q2 + (non QCD partons), where Q1 and Q2 are two different heavy quarks. We construct a new factorization scheme for threshold…
We derive the general structure of the hadronic tensor required to describe deep-inelastic scattering from an off-shell nucleon within a covariant formalism. Of the large number of possible off-shell structure functions we find that only…
This paper explores the effects of finite width in processes of pair production of a heavy eXtra Quark (XQ) with charge 2/3 and its subsequent decay into a Dark Matter (DM) candidate -- either scalar or vector -- and Standard Model (SM)…
I give a brief outline of the theoretical framework for the modern treatment of the strong interaction effects in heavy quark decays, based on first principles of QCD. This model-independent approach is required to meet the precision of…
The semi-inclusive decay processes of a top quark into a charged pseudo-scalar meson and a jet are studied within the framework of QCD factorization. The leading power of the decay matrix elements can be factorized into heavy-to-light quark…
We study $B\to \phi K$ and $B\to \phi X_s$ decays in the heavy quark limit using perturbative QCD. The next leading order corrections introduce substantial modifications to the naive factorization results (more than 50%). The branching…
We report on a recent calculation of the top decay rate up to order \alpha_s^2. It is based on asymptotic expansions of the off-shell top propagator, followed by a Pad\'e approximation in order to reach the physically relevant point…
Scalar and pseudo-scalar resonances decaying to top quarks are common predictions in several scenarios beyond the standard model (SM) and are extensively searched for by LHC experiments. Challenges on the experimental side require…
We analyze the decay $D_s\to \phi \pi$ with QCD factorization in the heavy quark limit. The nonfactorizable contributions, including hard spectator contribution are discussed and numerical results are presented. Our predictions on the…
We review selected topics in the field of nonleptonic and rare B meson decays. We concentrate in particular on exclusive channels, discussing recent developments based on the concepts of factorization in QCD and the heavy-quark limit.
We report new measurements and calculations of the non-resonant inelastic x-ray scattering (NRIXS) from Mg and Al for a wide range of momentum transfers, q. Extended oscillations in the dynamic structure factor S(q,w) due to scattering from…
Identification of boosted, hadronically-decaying top quarks is a problem of central importance for physics goals of the Large Hadron Collider. We present a theoretical analysis of top quark tagging, establishing zeroth-order, minimal…
This paper explores the effects of both finite width and interference (with background) in the pair production and decay of extra heavy quarks with charge 2/3 at the Large Hadron Collider (LHC). This dynamics is normally ignored in standard…
We present an improved method for handling off-shell effects in deep inelastic nuclear scattering. With a firm understanding of the effects of the nuclear wave function, including these off-shell corrections as well as binding and…
We show that maximally twisted mass fermions can be employed to regularize on the lattice the fully unquenched QCD+QED theory with vanishing $\theta$-term. We discuss how the critical mass of the up and down quarks can be conveniently…
We construct predictions for top quark pair differential distributions at hadron colliders that combine state-of-the-art NNLO QCD calculations with double resummation at NNLL' accuracy of threshold logarithms arising from soft gluon…
We compute the supersymmetric QCD corrections to the decay distribution of polarized top quarks for the semileptonic decay mode $t(\uparrow)\to b l^+\nu_l$. As a byproduct, we reinvestigate the SUSY-QCD corrections to the total decay width…
J/psi production in top quark rare decays is investigated under the framework of NRQCD factorization formalism. Various production channels are studied, and we find that the contributions from the color-singlet quark fragmentation and the…
We present a systematic comparison of different approaches for the modeling of $t\bar{t}\gamma$ final states with leptonic decays at the LHC. On the one hand, we consider a complete calculation at NLO QCD accuracy which includes all…