Measurement of prompt photon production in √SNN = 8.16 TeV p + Pb collisions with ATLAS

Research output: Contribution to journalArticle

  • External authors:
  • Agni Bethani
  • Brian Cox
  • Jonathan Crane
  • Cinzia Da Via
  • Nicholas Dann
  • Alessandra Forti
  • David Lack
  • Jiri Masik
  • Stephen Menary
  • Alexander Oh
  • Emily Orgill
  • Joleen Pater
  • Yvonne Peters
  • Yang Qin
  • Jacob Rawling
  • Nicolas Scharmberg
  • Savanna Shaw
  • Stephen Watts
  • Terence Wyatt
  • The ATLAS Collaboration

Abstract

The inclusive production rates of isolated, prompt photons in p+Pb collisions at √sNN=8.16 TeV are studied with the ATLAS detector at the Large Hadron Collider using a dataset with an integrated luminosity of 165 nb−1 recorded in 2016. The cross-section and nuclear modification factor RpPb are measured as a function of photon transverse energy from 20 GeV to 550 GeV and in three nucleon–nucleon centre-of-mass pseudorapidity regions, (−2.83,−2.02), (−1.84,0.91), and (1.09,1.90). The cross-section and RpPb values are compared with the results of a next-to-leading-order perturbative QCD calculation, with and without nuclear parton distribution function modifications, and with expectations based on a model of the energy loss of partons prior to the hard scattering. The data disfavour a large amount of energy loss and provide new constraints on the parton densities in nuclei.

Bibliographical metadata

Original languageEnglish
Pages (from-to)96-116
Number of pages20
JournalPhysics Letters B
Volume788
Early online date17 Jul 2019
DOIs
Publication statusPublished - 10 Sep 2019