Triple parton scatterings in high-energy proton-proton collisions

TL;DR

This paper develops a framework for calculating triple parton scattering cross sections in high-energy proton-proton collisions, relating it to single-parton cross sections and estimating its impact at LHC and FCC energies.

Contribution

It introduces a generic expression for triple parton scattering cross sections and estimates their significance at future collider energies, including the effective cross section parameter.

Findings

The effective cross section for TPS is approximately 12.5 mb.

At 100 TeV, about 15% of pp collisions produce three charm pairs.

Triple charm production becomes significant at high energies.

Abstract

A generic expression to compute triple parton scattering (TPS) cross sections in high-energy proton-proton (pp) collisions is presented as a function of the corresponding single-parton cross sections and the transverse parton distribution in the proton encoded in an effective parameter $\sigma_{\rm eff,TPS}$. The value of $\sigma_{\rm eff,TPS}$ is closely related to the similar effective cross section that characterizes double-parton scatterings, and amounts to $\sigma_{\rm eff,TPS} = 12.5 \pm 4.5$ mb. Estimates for triple charm ($\rm c\overline{c}$) and bottom ($\rm b\overline{b}$) production in pp collisions at LHC and FCC energies are presented based on next-to-next-to-leading order perturbative calculations for single $\rm c\overline{c},\rm b\overline{b}$ cross sections. At $\sqrt{s}\approx$ 100 TeV, about 15% of the pp collisions produce three $\rm c\overline{c}$ pairs from three different parton-parton scatterings.