Associated production of $J/\psi$ mesons and photons in the Parton Reggeization Approach and the double parton scattering model

TL;DR

This paper investigates the role of double parton scattering in producing $J/eta$ mesons and photons at the LHC, using the Parton Reggeization Approach and different hadronization models, revealing DPS dominance and model sensitivity.

Contribution

It introduces a detailed analysis of DPS contributions to $J/eta$ and photon production using PRA and compares hadronization models with experimental data.

Findings

DPS contribution exceeds SPS in $J/eta$ and photon production.

Predictions show strong sensitivity to the hadronization model used.

The study provides differential cross sections and correlation spectra at 13 TeV.

Abstract

We study the contribution of double parton scattering (DPS) to the associated production of $J/\psi$ mesons and photons with large transverse momenta in proton-proton collisions. Cross sections are computed within high-energy factorization using the Parton Reggeization Approach (PRA). We used two frameworks for hadronization of the $c\bar c$ pair into charmonium: nonrelativistic QCD (NRQCD) and the improved color evaporation model (ICEM). Hadronization model parameters are fixed using single $J/\psi$ production experimental data from the CMS and ATLAS collaborations at the Large Hadron Collider (LHC). We show that the DPS contribution significantly exceeds the single parton scattering (SPS) contribution and that theoretical predictions are strongly sensitive to the choice of hadronization model. We made predictions for various differential cross sections and correlation spectra for the associated $J/\psi$ and photon production at $\sqrt{s}=13$ TeV.