Jet and missing transverse momentum reconstruction in ATLAS at the LHC

Abstract

Particle jets and the missing transverse momentum (ETmiss) generated by the proton–proton collisions at the Large Hadron Collider (LHC) at CERN are important components of the final state reconstruction with the ATLAS detector. Both jet and ETmiss reconstruction during LHC Run 2 (2015–2018), where the protons were collided with a centre-of-mass energy of √s = 13 TeV, faced significant challenges due to the high beam intensities that introduced the highest level of pile-up so far. Selected results from the evaluation of the jet and ETmiss reconstruction performances are presented. Notably, the achieved precision of the jet energy measurement is about 1% over a large fraction of the accessible phase space for both narrow and wide jets, thus preserving the precision reached in previous LHC operations with significantly lower pile-up.