Production of two $c \bar c$ pairs in gluon-gluon scattering in high energy proton-proton collisions

TL;DR

This paper calculates the production cross sections for two charm-anticharm pairs in high-energy proton-proton collisions, comparing single-parton and double-parton scattering contributions, and finds DPS dominates at energies above 5 TeV.

Contribution

It provides the first detailed calculation of SPS cross sections for double $c ar c$ production in high-energy collisions, including differential distributions and comparison with DPS results.

Findings

SPS contribution is much smaller than DPS at energies above 5 TeV.

Differential distributions in rapidity, transverse momentum, and invariant mass are presented.

The study highlights the dominance of DPS over SPS in double charm production at high energies.

Abstract

We calculate cross sections for $g g \to Q \bar Q Q \bar Q$ in the high-energy approximation in the mixed (longitudinal momentum fraction, impact parameter) and momentum space representations. Besides the total cross section as a function of subsystem energy also differential distributions (in quark rapidity, transverse momentum, $Q Q$, $Q \bar Q$ invariant mass) are presented. The elementary cross section is used to calculate production of $(c \bar c) (c \bar c)$ in single-parton scattering (SPS) in proton-proton collisions. We present integrated cross section as a function of proton-proton center of mass energy as well as differential distribution in $M_{(c \bar c)(c \bar c)}$. The results are compared with corresponding results for double-parton scattering (DPS) discussed recently in the literature. We find that the considered SPS contribution to $(c \bar c)(c \bar c)$ production is at high energy ($\sqrt{s} >$ 5 TeV) much smaller than that for DPS contribution.