Related papers: Constraints on the Gluon Density from Lepton Pair …
The hadroproduction of lepton pairs with mass $Q$ and transverse momentum $Q_T$ can be described in perturbative QCD by the same partonic subprocesses as prompt photon production. We demonstrate that, like prompt photon production, lepton…
The hadroproduction of lepton pairs with mass $Q$ and finite transverse momentum $Q_T$ is dominated by quark-gluon scattering in the region $Q_T > Q/2$. This feature provides a new independent method for constraining the gluon density with…
Massive lepton-pair production, the Drell-Yan process, should be a good source of independent constraints on the gluon density, free from the experimental and theoretical complications of photon isolation that beset studies of prompt photon…
We discuss the transverse momentum distribution for the production of massive lepton-pairs in hadron reactions at fixed target and collider energies within the context of next-to-leading order perturbative quantum chromodynamics. For values…
We demonstrate that not only the production of virtual photons decaying into low-mass lepton pairs, but also the one of weak bosons at large transverse momenta is dominated by quark-gluon scattering. Measurements of these processes at the…
We analyze the capability of prompt photon production in pp and pp(bar) collisions to constrain the gluon distribution of the proton, considering data from fixed-target experiments as well as collider measurements. Combined fits are…
We study the transverse momentum distribution of low-mass lepton pairs produced in hadronic scattering, using the perturbative QCD factorization approach. We argue that the distribution at large transverse momentum, $Q_T \gg Q$, with the…
We investigate lepton-pair production in hard exclusive hadron-hadron collisions. We consider a double handbag (DH) mechanism in which the process amplitude factorizes in hard subprocesses, qq -> qq gamma* and qg -> qg gamma*, and in soft…
We argue that the collinear factorization of the fragmentation functions in high energy hadron and nuclei collisions breaks down at transverse momenta kT < Qs/g due to high parton densities in the colliding hadrons and/or nuclei. We…
We calculate the transverse momentum distribution for the production of massive lepton-pairs in longitudinally polarized proton-proton reactions at collider energies within the context of perturbative quantum chromodynamics. For values of…
We study the production of transversely polarized Lambda hyperons in high-energy collisions of protons with large nuclei. The large gluon density of the target at saturation provides an intrinsic semi-hard scale which should naturally allow…
The Common Muon Proton Apparatus for Structure and Spectroscopy (COMPASS) at CERN with its use of beams of naturally polarized muons scattered of a polarized deuteron target, provides an environment of hard scattering between quasi-real…
The study of azimuthal correlations in particle production at forward rapidities in proton-nucleus collisions provides direct information about high gluon density effects, like gluon saturation, in the nuclear wavefunction. In the…
The amplitude for production of a single photon associated with quark pair in the fusion of two off-shell gluons is calculated. The matrix element found is applied to the inclusive prompt photon hadroproduction at high energies in the…
The production rate and kinematic distributions of isolated photon pairs produced in hadron interactions are studied. The effects of the initial-state multiple soft-gluon emission to the scattering subprocesses q-qbar, qg, and gg to gamma…
We compute the contributions to continuum photon pair production at hadron colliders from processes initiated by gluon-gluon and gluon-quark scattering into two photons through a four-leg virtual quark loop. Complete two-loop cross sections…
In this article, we investigate the potential of low-mass lepton pair production in proton-ion collisions at the LHC to constrain nuclear modifications of parton densities. Similarly to prompt photon production, the transverse momentum…
We propose a new formula for extracting the polarized gluon distribution from the large-$p_T$ light hadron pair production for semi-inclusive processes in polarized deep inelastic scattering. In general, a large-$p_T$ hadron pair is…
We use perturbative QCD, beyond the leading $\ln Q^2$ approximation, to show how measurements of diffractive $J/\psi$ production at HERA can provide a sensitive probe of the gluon density of the proton at small values of Bjorken $x$. We…
We consider the photoproduction of two hadrons in polarized lepton-nucleon collisions in the framework of perturbative QCD at the next-to-leading order accuracy. After illustrating how to obtain the experimentally relevant observables, a…