Investigation of initial state effects in p+Pb collisions at ATLAS via measurement of both top quark and dijet production

29 Mar 2023, 09:40
Ludwig 1a (Stadthalle)

Ludwig 1a


Talk Early time dynamics and nuclear PDFs Parallel: Early-Time Dynamics & nPDFs


Riccardo Longo


Proton-lead collisions at LHC energies offer unique possibilities to investigate the nuclear modifications of parton distribution functions (PDF) over a wide kinematic range. Several probes can be measured to characterize these effects in different kinematic regimes. The top-quark production is expected to be sensitive to effects at high Bjorken-x values, which are hard to access experimentally using other available probes. Conversely, dijet production can provide constraints on nPDFs over a wide kinematic range that extends down to Bjorken-x~$10^{-4}$. In 2016 the ATLAS experiment collected 164 nb$^{-1}$ of proton-lead collisions at a centre-of-mass energy of 8.16 TeV per nucleon pair. In this talk, we will present two new results obtained from the analysis of this dataset: the first measurement of the inclusive cross-section for top-quark pair production in dilepton and lepton+jets decay modes with electrons and muons, and the measurement of inclusive dijet cross-section. The results are compared to the NLO and NNLO predictions for dijet production and top-quark production using various PDF sets, respectively.


ATLAS Collaboration

Experiment/Theory ATLAS

Primary author

Presentation Materials