Related papers: Photon TMD
The accurate description of the internal structure of hadrons is a very challenging task. In order to compare the predictions with the highly-accurate experimental data, it is necessary to control any possible source of theoretical…
We update our extraction of parton-to-charged hadron fragmentation functions at next-to-leading order accuracy in QCD, focusing on the wealth of data collected at the Large Hadron Collider over the past decade. We obtain an accurate…
We investigate different methods to incorporate the effect of photons in hard processes. We compare two different approaches used for calculating cross sections for two-photon $p p \to l^+ l^- X$ process. In one of the approaches photon is…
We present a calculation of the generalized parton distributions of the photon when there is non-zero momentum transfer both in the transverse and longitudinal directions. We consider only the contributions when the photon helicity is not…
The discussion on the production of prompt photons with pT of a few GeV in the tagged process ep -> e gamma X with small Q^2 (DIC process) at the HERA collider is presented. Photons produced in the forward (proton) direction are mainly…
A dark photon is predicted by several well-motivated Standard Model extensions and UV completions. Here the most general effective field theory up to dimension-six operators describing the interactions of a massless dark photon with all…
The double-differential inclusive di-jet cross section in photoproduction processes is measured with the H1 detector at HERA. The cross section is determined as a function of the average transverse jet energy E_T^jets for ranges of the…
We present a complete next-to-leading order QCD calculation for single-inclusive large-pT hadron production in longitudinally polarized lepton-nucleon collisions, consistently including ``direct'' and ``resolved'' photon contributions. This…
Production of lepton pairs in gamma p -> e-e+ p reaction is studied at photon energies up to 1 GeV. We show that even if lepton charge is not measured there are extensive kinematical regimes where the nuclear process dominates over the…
We describe a new way to access the chiral odd transversity parton distribution in the proton through the photoproduction of lepton pairs on transversely polarized target. The basic ingredient is the interference of the Bethe Heitler or…
Structures which appear to move at or near the velocity of light contain singular points. Energy generated by the motion accumulates at these points into ever-narrowing peaks. In this paper we show that energy is generated by a curious…
This work introduces a novel, nonparametric pixel-based framework for the Bayesian inference and imaging of transverse momentum dependent (TMD) parton distributions. The methodology is built upon a fully differentiable framework that…
The matrix element squared for Compton scattering of a heavy photon on a longitudinally polarized electron is calculated. The gauge-invariant tensor structure of the heavy photon polarization is considered, assuming that all kinematical…
We develop the analysis of diphoton exclusive photoproduction in the kinematics where a collinear QCD factorization framework applies, namely nearly forward large invariant mass diphoton production. We work at the leading twist level and at…
We reconsider the prompt photon photoproduction at HERA in the framework of the $k_T$-factorization QCD approach. The proposed method is based on the ${\cal O}(\alpha^2\alpha_s)$ amplitudes for $\gamma q\to\gamma gq$ and $\gamma…
The prompt photon production in hadronic collisions has a long history of providing information on the substructure of hadrons and testing the perturbative techniques of QCD. Some valuable information about the parton densities in the…
The QCD phenomenology of prompt photon production from e-p to p-p/p-pbar and A-A collisions is reviewed. The use of prompt photons as a probe of (i) parton distribution functions (in a proton or in nuclei) as well as (ii) fragmentation…
Heavy quarks are copiously produced in two-photon collisions at $e^+e^-$ colliders. The theoretical predictions including QCD radiative corrections are compared to recent experimental data on $\gamma\gamma$ production of charm quarks at…
Cross section of the processes of neutral pion production as well as pairs of charged fermions and bosons in peripherical interaction of leptons, photons are calculated in main logarithmical approximation. We investigate the phase volumes…
An earlier developed $k_T$-factorization framework to calculate the associated prompt photon and hadronic jets production cross sections at high energies is extended now to the electron-proton deep inelastic scattering. The proposed method…