Related papers: Photon TMD
We present the first determination of transverse momentum dependent (TMD) photon densities with the Parton Branching method. The photon distribution is generated perturbatively without intrinsic photon component. The input parameters for…
Parton densities are obtained from a solution of the extended DGLAP-type evolution equation that includes both QCD and electroweak contributions. The equations are solved using the Parton-Branching (PB) approach, and the evolution is…
Collinear and transverse momentum dependent (TMD) parton densities are obtained from fits to precision measurements of deep inelastic scattering (DIS) cross sections at HERA. The parton densities are evolved by DGLAP evolution with…
In the framework of the QCD parton model, we study unpolarized scattering of high energy real photons from a proton target into lepton pairs and a system of hadrons. For a given parametrization of parton distributions in the proton, we…
Photoproduction of a pair of particles with large invariant mass is a natural extension of collinear QCD factorization theorems which have been much studied for deeply virtual Compton scattering and deeply virtual meson production. We…
A consistent description of exclusive photoproduction of mesons at high momentum transfer t relies on a few effective degrees of freedom which can be checked against Lattice calculation or more effective models of QCD.
Photoproduction data collected with the H1 detector at HERA in 1994 are used to study the cross-sections for inclusive charged particle production and the structure of the photon. The differential cross-sections dsigma/dpT2, for |eta| < 1…
The experimental and phenomenological status of high energy photoproduction is reviewed. Topics covered include the structure of the photon, production of jets, heavy flavours and prompt photons, rapidity gaps, energy flow and underlying…
This paper investigates the electromagnetic production of lepton pairs with low transverse momentum in relativistic heavy ion collisions. We estimate the initial photons' transverse momentum contributions by employing models where the…
We study the associated production of real (isolated) or virtual photons (with their subsequent leptonic decay) and hadronic jets in proton-proton collisions at the LHC using the $k_T$-factorization approach of QCD. The consideration is…
A global QCD analysis of the direct photon production process from both fixed target and collider experiments is presented. These data sets now completely cover the parton $x$ range from 0.01 to 0.6, thereby providing a stringent test of…
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…
We present a Monte-Carlo approach to prompt-photon production, where photons and QCD partons are treated democratically. The photon fragmentation function is modelled by an interleaved QCD+QED parton shower. This known technique is improved…
The hadroproduction of lepton pairs with mass Q and finite transverse momentum Q_T is described in perturbative QCD by the same partonic subprocesses as prompt photon production. We demonstrate that, like prompt photon production, lepton…
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…
In this work, we have calculated the photon leading-twist T-even transverse momentum dependent parton distribution functions (TMDs). For these calculations, we have treated photon as a state of quark anti-quark pair and represent the TMDs…
We calculate the photon production cross section arising from the hard scattering of partons in nucleon-nucleon collisions by taking into account the intrinsic parton transverse momentum distribution and the next-to-leading-order…
We calculate the production of high energy photons from Compton and annihilation processes as well as fragmentation off quarks in the parton cascade model. The multiple scattering of partons is seen to lead to a substantial production of…
We investigate the prompt photon photoproduction at HERA within the framework of kt-factorization QCD approach. Our consideration is based on the off-shell matrix elements for the underlying partonic subprocesses. The unintegrated parton…
Photon-photon collisions are investigated in the framework of the two-component Dual Parton Model. The model is shown to agree well to hadron production data from hadron-hadron and photon-hadron collisions. The multiparticle production in…