Comparison between simulated and observed LHC beam backgrounds in the ATLAS experiment at $E_{\text{beam}}$ = 4 TeV

Abstract

Results of dedicated Monte Carlo simulations of beam-induced background (BIB) in the ATLAS experiment at the Large Hadron Collider (LHC) are presented and compared with data recorded in 2012. During normal physics operation this background arises mainly from scattering of the 4 TeV protons on residual gas in the beam pipe. Methods of reconstructing the BIB signals in the ATLAS detector, developed and implemented in the simulation chain based on the FLUKA Monte Carlo simulation package, are described. The interaction rates are determined from the residual gas pressure distribution in the LHC ring in order to set an absolute scale on the predicted rates of BIB so that they can be compared quantitatively with data. Through these comparisons the origins of the BIB leading to different observables in the ATLAS detectors are analysed. The level of agreement between simulation results and BIB measurements by ATLAS in 2012 demonstrates that a good understanding of the origin of BIB has been reached.

arXiv comment44 pages in total, author list starting on page 28, 14 figures, 4 tables, published in JINST, figures available on https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/DAPR-2017-01

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Cited by in corpus (4)

• Search for long-lived neutral particles produced in $pp$ collisions at $\sqrt{s}=13$ TeV decaying into displaced hadronic jets in the ATLAS inner detector and muon spectrometer
• Measurement of photonuclear jet production in ultra-peripheral Pb+Pb collisions at $\sqrt{s_{\text{NN}}}=5.02$ TeV with the ATLAS detector
• Search for magnetic monopole pair production in ultraperipheral Pb+Pb collisions at $\sqrt{s_{{}_{\text{NN}}}}=5.36$ TeV with the ATLAS detector at the LHC
• Beam-induced backgrounds measured in the ATLAS detector during local gas injection into the LHC beam vacuum