p-p((p)over-bar) cross section of isolated single photon production in the kt factorization and different angular ordering unintegrated parton distributions frameworks

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) over bar) 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 DO (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 subprocesses, (ii) the possible double-counting between the 2 -> 2 and 2 -> 3 subprocesses, 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.

Automated summary

In this study, differential cross sections of prompt single-photon production are calculated using various parton distribution functions, successfully predicting and analyzing compared to experimental data and other theoretical predictions. Extensive discussions and comparisons are made regarding the behavior of contributing partonic subprocesses and sensitivity of results to different angular ordering constraints.