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Committee for collaboration of Czech Republic

with Joint Institute for Nuclear Research in Dubna Login
Constraining Gluon Distributions in Nuclei Using Dijets in Proton-Proton and Proton-Lead Collisions at root s(NN)=5.02 TeV

Author
Sirunyan A.M. Yerevan Physics Institute, Armenia
Finger Miroslav, prof. Ing. DrSc. Faculty of Mathematics and Physics, Charles University in Prague
Finger Michael, M.Sc. CSc. Faculty of Mathematics and Physics, Charles University in Prague, JINR Dubna
et al.  CMS collaboration

Year
2018

Scientific journal
Physical Review Letters, 121 (6), 062002

Web


Abstract
The pseudorapidity distributions of dijets as functions of their average transverse momentum (p(T)(ave)) are measured in proton-lead (pPb) and proton-proton (pp) collisions. The data samples were collected by the CMS experiment at the CERN LHC, at a nucleon-nucleon center-of-mass energy of 5.02 TeV. A significant modification of the pPb spectra with respect to the pp spectra is observed in all p(T)(ave) intervals investigated. The ratios of the pPb and pp distributions are compared to next-to-leading order perturbative quantum chromodynamics calculations with unbound nucleon and nuclear parton distribution functions (PDFs). These results give the first evidence that the gluon PDF at large Bjorken x in lead ions is strongly suppressed with respect to the PDF in unbound nucleons.

Cite article as:
A. Sirunyan, M. Finger, M. Finger, . et al., "Constraining Gluon Distributions in Nuclei Using Dijets in Proton-Proton and Proton-Lead Collisions at root s(NN)=5.02 TeV", Physical Review Letters, 121 (6), 062002 (2018)