Jet and missing transverse momentum reconstruction in ATLAS at the LHC

Particle jets and the missing transverse momentum (E_T^miss) 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 E_T^miss 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 E_T^miss 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.