The P-P(\={P}) cross-section of isolated single-photon production in the $k_t$-factorization and different angular ordering unintegrated parton distributions frameworks

TL;DR

This study calculates prompt single-photon production cross-sections in high-energy proton-proton collisions using $k_t$-factorization with various unintegrated parton distributions, comparing results with experimental data and other models.

Contribution

It introduces a detailed analysis of prompt photon production using different angular ordering UPDF frameworks at NLO, comparing with experimental data and other theoretical approaches.

Findings

Calculated cross-sections agree well with experimental data.

Different UPDF schemes show varying contributions to the cross-sections.

The study discusses potential double-counting and angular ordering effects.

Abstract

In the present work, it is intended to calculate and study the single and double differential cross-sections of the prompt single-photon production as a function of produced single-photon transverse momentum and rapidity, in the high-energy P-P(\={P}) colliders, such as LHC and TEVATRON. The differential cross-sections of prompt single-photon production are calculated in the $k_t$-factorization frameworks using various angular ordering unintegrated parton distribution functions (UPDF), namely the Kimber et al. and Martin et al. procedures. These scheme-dependent UPDF are generated in the leading and next-to-leading order levels to predict and analyze the different partonic contributions to the above cross-sections. The above two procedures utilize the phenomenological parton distribution functions (PDF) libraries of Martin et al., i.e., MMHT2014. It is shown that the calculated prompt single-photon production differential cross-sections in the above frameworks are relatively successful in generating satisfactory results compared to the experimental data of different collaborations, i.e., CDF (2017), ATLAS (2017), CMS (2011) and D0 (2006), as well as the other theoretical predictions such as collinear factorization Monte Carlo calculations (the JETPHOX, SHERPA, PYTHIA, and MCFM methods). Also, for a closer precision, the differential cross-section for the NLO gluon-gluon , quark-gluon and quark-(anti)quark processes are calculated. An extensive discussion and comparison are made regarding (i) the behavior of the contributing partonic sub-processes, (ii) the possible double-counting between the $2\to 2$ and $2\to 3$ sub-processes, i.e., gluons-fusion, in our calculated prompt single-photon production differential cross-sections and (iii) the sensibility check of our results to the different angular ordering constraints.