Average Event Properties from LHC to FCC-hh

TL;DR

This paper predicts average soft-QCD event properties for future proton-proton colliders at 14, 27, and 100 TeV using PYTHIA 8.2, providing uncertainty estimates based on current LHC constraints.

Contribution

It offers the first detailed extrapolation of soft-QCD observables to future collider energies with uncertainty analysis using current event generator tunes.

Findings

Predicted total and inelastic cross sections at higher energies.

Estimated track densities and average transverse momentum per event.

Projected jet cross sections at 50 and 100 GeV for future collider conditions.

Abstract

In the context of design studies for future $pp$ colliders, we present a set of predictions for average soft-QCD event properties for $pp$ collisions at $E_\mathrm{CM} = 14$, $27$, and $100$ TeV. The current default Monash 2013 tune of the PYTHIA 8.2 event generator is used as the baseline for the extrapolations, with uncertainties evaluated via variations of cross-section parametrisations, PDFs, MPI energy-scaling parameters, and colour-reconnection modelling, subject to current LHC constraints. The observables included in the study are total and inelastic cross sections, inelastic average energy and track densities per unit pseudorapidity (inside $|\eta|\le 6$), average track $p_\perp$, and jet cross sections for 50- and 100-GeV anti-$k_T$ jets with $\Delta R=0.4$, using aMC@NLO in conjunction with PYTHIA 8 for the latter.