Minimum Bias and Underlying Event Measurements with ATLAS

TL;DR

This paper reports on ATLAS measurements of minimum bias and underlying events in proton-proton collisions at various energies, highlighting discrepancies with Monte Carlo models and revealing limitations in current phenomenological descriptions.

Contribution

It provides new experimental data on minimum bias and underlying events at multiple energies, and critically compares these to existing Monte Carlo predictions.

Findings

Measurements reveal limitations of current models in describing data

Data at 0.9, 2.36, and 7 TeV show discrepancies with predictions

Results highlight areas for improving phenomenological models

Abstract

A summary of some of the recent minimum bias and underlying event measurements by the ATLAS collaboration is given. The results of several analyses using low-luminosity proton-proton collision data from the LHC taken at center-of-mass energies of sqrt(s) = 0.9, 2.36 and 7 TeV are presented. Data are compared to predictions by several different Monte Carlo event generators. The measurements expose limitations of the phenomenological models in properly describing the measured observables in all regions of phase space.