PT Journal
AU ATLAS Collaboration (Aaboud, Mea
   Alvarez Piqueras, D
   Aparisi Pozo, JA
   Bailey, AJ
   Barranco Navarro, L
   Cabrera Urban, S
   Castillo, FL
   Castillo Gimenez, V
   Cerda Alberich, L
   Costa, MJ
   Escobar, C
   Estrada Pastor, O
   Ferrer, A
   Fiorini, L
   Fullana Torregrosa, E
   Fuster, J
   Garcia, C
   Garcia Navarro, JE
   Gonzalez de la Hoz, S
   Higon-Rodriguez, E
   Jimenez Pena, J
   Lacasta, C
   Lozano Bahilo, JJ
   Madaffari, D
   Mamuzic, J
   Marti-Garcia, S
   Melini, D
   Miñano, M
   Mitsou, VA
   Rodriguez Bosca, S
   Rodriguez Rodriguez, D
   Ruiz-Martinez, A
   Salt, J
   Santra, A
   Soldevila, U
   Sanchez, J
   Valero, A
   Valls Ferrer, JA
   Vos, M
TI Measurement of prompt photon production in root s(NN)=8.16 TeV p Pb collisions with ATLAS
SO Physics Letters B
JI Phys. Lett. B
PY 2019
BP 230
EP 252
VL 796
DI 10.1016/j.physletb.2019.07.031
LA English
AB The inclusive production rates of isolated, prompt photons in p Pb collisions at root s(NN) = 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 R-p pb 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 R-p pb 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.
ER