Global properties of proton-proton collisions at $\sqrt{s}$ = 100 TeV

Abstract

The global properties of the final states produced in hadronic interactions of protons at centre-of-mass energies of future hadron colliders (such as FCC-hh at CERN, and SppC in China), are studied. The predictions of various Monte Carlo (MC) event generators used in collider physics (PYTHIA 6, PYTHIA 8, and PHOJET) and in ultrahigh-energy cosmic-rays studies (EPOS, and QGSJET) are compared. Despite their different underlying modeling of hadronic interactions, their predictions for proton-proton (p-p) collisions at $\sqrt{s}$ = 100 TeV are quite similar. The average of all MC predictions (except PHOJET) for the different observables are: (i) p-p inelastic cross sections ${\sigma }_{\mathrm{inel}}$ = 105 $\pm$ 2 mb; (ii) total charged multiplicity ${\mathrm{N}}_{{}_{\mathrm{ch}}}$ = 150 $\pm$ 20; (iii) charged particle pseudorapidity density at midrapidity $\mathrm{d}{\mathrm{N}}_{\mathrm{ch}}/d\eta {|}_{\eta =0}=9.6\pm 0.2$; (iv) energy density at midrapidity $dE/d\eta {|}_{\eta =0}=13.6\pm 1.5$ GeV, and $dE/d\eta {|}_{\eta =5}=670\pm 70$ GeV at the edge of the central region; and (v) average transverse momenta at midrapidities $<{\mathrm{p}}_{\mathrm{T}}>=0.76\pm 0.07$ GeV/c. At midrapidity, EPOS and QGSJET-II predict larger per-event multiplicity probabilities at very low (${\mathrm{N}}_{\mathrm{ch}}<3$) and very high (${\mathrm{N}}_{\mathrm{ch}}>100$) particle multiplicities, whereas PYTHIA 6 and 8 feature higher yields in the intermediate region ${\mathrm{N}}_{\mathrm{ch}}\approx$ 30--80. These results provide useful information for the estimation of the detector occupancies and energy deposits from pileup collisions at the expected large FCC-hh/SppC luminosities.

Comments: 10 pages, 11 figures. Minor changes. Matches version published in JHEP