Related papers: Colour-Octet Effects in Radiative $\Upsilon$ Decay…
In this study, we conduct an enhanced investigation of pure annihilation-type charmless hadronic B-decays within the framework of the PQCD approach. Specifically, we account for the quark-loop enhanced contribution to various decay…
Motivated by recent experimental advances in the corresponding measurements, non-leptonic hyperon decays are calculated, for the first time in a relativistic manner, in Chiral Perturbation Theory at next-to-leading order (NLO). On the one…
We show that the colour-singlet contributions to the hadroproduction of J/psi in association with a W boson are sizable, if not dominant over the colour-octet contributions. They are of two kinds, sg -> J/psi + c + W at alpha^3_S alpha and…
Non-Relativistic QCD (NRQCD) has provided a consistent framework for the physics of quarkonia. The colour-octet Fock components predicted by NRQCD have important implications for the phenomenology of quarkonium production in experiments. We…
Within the Color Glass Condensate effective theory, we reconsider the next-to-leading order (NLO) calculation of the single inclusive particle production at forward rapidities in proton-nucleus collisions at high energy. Focusing on quark…
The question how well nonrelativistic QCD (NRQCD) factorization can describe quarkonium production has been subject to debate since its invention. We review our recent reanalysis of a classic next-to-leading order color octet (CO) long…
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 apply the QCD factorization approach to exclusive, radiative B meson decays in the region of small invariant photon mass. We calculate factorizable and non-factorizable corrections to leading order in the heavy quark mass expansion and…
We revisit inclusive J/psi and Upsilon photoproduction at lepton-hadron colliders, namely in the limit when the exchanged photon is quasi real. Our computation includes the next-to-leading-order (NLO) alpha_s corrections to the…
We study two-body exclusive decays of the form B -> D^(*) L (L = \pi, \rho) in the heavy quark limit. We perform a renormalon analysis of such processes to determine the order at which nonperturbative factorization-breaking power…
New predictions regarding the role of color flow in high energy Quantum Chromodynamics (QCD) processes have emerged in the last decade. In particular, the role of color flow is now being explored through many different observables; one such…
We calculate the order alpha_s^2 and order alpha_s^3 QCD contributions to colour-singlet exchange in the leading log s approximation. We implement the resulting amplitude at the hadronic level and thus construct the QCD pomeron and odderon…
We consider QCD radiative corrections to $W^+W^-b {\bar b}$ production with leptonic decays and massive bottom quarks at the LHC. We perform an exact next-to-leading order (NLO) calculation within the $q_T$-subtraction formalism and…
We present the first calculation of direct photon production at next-to-next-to leading order (NNLO) accuracy in QCD. For this process, although the final state cuts mandate only the presence of a single electroweak boson, the underlying…
In the framework of the nonrelativistic quantum chromodynamics factorization formalism, we study the processes of $\psi(nS)$ and $\Upsilon(nS)$ decay into a lepton pair or a charm pair associated with two jets up to the next-to-leading…
The photon -- induced interactions, present in $ep$, $eA$, $pp$, $pA$, $AA$ and $e^+ e^-$ collisions, are expressed within the color dipole approach in terms of the photon wave function, which describes the transition of the photon into a…
We investigate the effect of high order radiative corrections in unpolarized electron proton elastic scattering and compare with the calculations at lowest order, which are usually applied to experimental data. Particular attention is…
By employing the perturbative QCD(pQCD) factorization approach, we calculated the partial next-to-leading order (NLO) contributions to $B_s \to P P$ decays ($P= \pi, K, \etap $), coming from the QCD vertex corrections, the quark-loops and…
We study the nonleptonic decays of $B\to PP$ in the modified perturbative QCD approach, where $P$ stands for pseudoscalar mesons. Transverse momenta of partons and the Sudakov factor are included, which help to suppress the contributions of…
A next-to-leading order correction to the high-energy factorization limit of radiation spectrum from an ultrarelativistic electron scattering in an external field is evaluated. Generally, it does not express through scattering…