Nuclear transverse momentum dependent gluon density at low $x$ and inclusive soft hadron production in proton-lead collisions at LHC

A. V. Lipatov; G. I. Lykasov; M. A. Malyshev

Nuclear transverse momentum dependent gluon density at low $x$ and inclusive soft hadron production in proton-lead collisions at LHC

A. V. Lipatov, G. I. Lykasov, M. A. Malyshev

Abstract

We report the results of calculations of inclusive soft hadron production in proton-lead collisions at the LHC in the framework of modified quark-gluon string model (QGSM) extended to $pA$ interactions. Our consideration involves the nuclear modification of previously proposed transverse momentum dependent (TMD, or unintegrated) gluon density in a proton, which provides a self-consistent simultaneous description of numerous HERA and LHC data on $pp$, $ep$ and $γp$ processes. Such nuclear modification is based on well established property of geometrical scaling from nucleons to nuclei. Focusing on the region of small $x$ and low scales, we obtain predictions for transverse momentum spectra of pions and kaons at $p_T \leq 1$~GeV. Our results are compared with recent data reported by the CMS, ATLAS and ALICE Collaborations at $\sqrt s = 5.02$~TeV. We find that the developed approach provides a better description of low-$p_T$ data than the predictions made by other groups.

Nuclear transverse momentum dependent gluon density at low $x$ and inclusive soft hadron production in proton-lead collisions at LHC

Abstract

We report the results of calculations of inclusive soft hadron production in proton-lead collisions at the LHC in the framework of modified quark-gluon string model (QGSM) extended to

interactions. Our consideration involves the nuclear modification of previously proposed transverse momentum dependent (TMD, or unintegrated) gluon density in a proton, which provides a self-consistent simultaneous description of numerous HERA and LHC data on

and

processes. Such nuclear modification is based on well established property of geometrical scaling from nucleons to nuclei. Focusing on the region of small

and low scales, we obtain predictions for transverse momentum spectra of pions and kaons at

~GeV. Our results are compared with recent data reported by the CMS, ATLAS and ALICE Collaborations at

~TeV. We find that the developed approach provides a better description of low-

data than the predictions made by other groups.

Paper Structure (13 equations, 3 figures)

This paper contains 13 equations, 3 figures.

Figures (3)

Figure 1: Quark/diquark (black dash-dotted) and gluon (gray dashed) contributions to the inclusive spectrum of soft charged hadrons calculated at $\sqrt{s} = 2.36$, $5.02$ and $13$ TeV. Sum of all contributions is represented by the green line.
Figure 2: Pions transverse momenta spectra calculated within our approach compared with available LHC data for $p_T < 1$ GeV. The uncertainties of the fit procedure are shown as brown bands. The data of CMS ChargedHadron5-CMS, ATLAS ChargedHadron5-ATLAS and ALICE ChargedHadron5-ALICE were taken at $\sqrt{s}=$ 5.02 TeV and summed over the collision centralities.
Figure 3: Kaons transverse momenta spectra calculated within our approach compared with available LHC data for $p_T < 1$ GeV. The uncertainties of the fit procedure are shown as brown bands. The data of CMS ChargedHadron5-CMS, ATLAS ChargedHadron5-ATLAS and ALICE ChargedHadron5-ALICE were taken at $\sqrt{s}=$ 5.02 TeV and summed over the collision centralities.