The production of prompt charged particles in proton-lead collisions and in proton-proton collisions at the nucleon-nucleon center-of-mass energy root s(NN) = 5 TeV is studied at LHCb as a function of pseudorapidity (eta) and transverse momentum (p(T) ) with respect to the proton beam direction. The nuclear modification factor for charged particles is determined as a function of eta between -4.8 < eta < -2.5 (backward region) and 2.0 < eta < 4.8 (forward region), and p(T) between 0.2 < p(T) < 8.0 GeV/c. The results show a suppression of charged particle production in proton-lead collisions relative to proton-proton collisions in the forward region and an enhancement in the backward region for p(T) larger than 1.5 GeV/c. This measurement constrains nuclear PDFs and saturation models at previously unexplored values of the parton momentum fraction down to 10(-6).
Aaij, R., Beteta, C.a., Ackernley, T., Adeva, B., Adinolfi, M., Afsharnia, H., et al. (2022). Measurement of the nuclear modification factor and prompt charged particle production in p-Pb and pp collisions at root s(NN )=5 TeV. PHYSICAL REVIEW LETTERS, 128(14) [10.1103/PhysRevLett.128.142004].
Measurement of the nuclear modification factor and prompt charged particle production in p-Pb and pp collisions at root s(NN )=5 TeV
Archilli, F.;Santovetti, E.Membro del Collaboration Group
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2022-01-01
Abstract
The production of prompt charged particles in proton-lead collisions and in proton-proton collisions at the nucleon-nucleon center-of-mass energy root s(NN) = 5 TeV is studied at LHCb as a function of pseudorapidity (eta) and transverse momentum (p(T) ) with respect to the proton beam direction. The nuclear modification factor for charged particles is determined as a function of eta between -4.8 < eta < -2.5 (backward region) and 2.0 < eta < 4.8 (forward region), and p(T) between 0.2 < p(T) < 8.0 GeV/c. The results show a suppression of charged particle production in proton-lead collisions relative to proton-proton collisions in the forward region and an enhancement in the backward region for p(T) larger than 1.5 GeV/c. This measurement constrains nuclear PDFs and saturation models at previously unexplored values of the parton momentum fraction down to 10(-6).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.