Measurements of differential cross sections for inclusive very forward
jet production in proton-lead collisions as a function of jet energy
are presented. The data were collected with the CMS experiment at the
LHC in the laboratory pseudorapidity range 6 : 6 < < 5 : 2.
Asymmetric beam energies of 4TeV for protons and 1.58TeV per nucleon for
Pb nuclei were used, corresponding to a center-of-mass energy per
nucleon pair of p sNN = 5 : 02TeV. Collisions with either the proton (p+
Pb) or the ion (Pb+ p) traveling towards the negative hemisphere are
studied. The jet cross sections are unfolded to stable-particle level
cross sections with pT & 3 GeV, and compared to predictions from
various Monte Carlo event generators. In addition, the cross section
ratio of p+ Pb and Pb+ p data is presented. The results are discussed in
terms of the saturation of gluon densities at low fractional parton
momenta. None of the models under consideration describes all the data
over the full jet-energy range and for all beam con fi gurations.
Discrepancies between the di ff erential cross sections in data and
model predictions of more than two orders of magnitude are observed.
- 114 Physical sciences
- Forward physics
- Hadron-Hadron scattering (experiments)
- Heavy-ion collision
- COLOR GLASS CONDENSATE
- NONLINEAR GLUON EVOLUTION