On the rapidity dependence of the average transverse momentum in hadronic collisions

Abstract

The energy and rapidity dependence of the average transverse momentum $⟨p_T⟩$ in $pp$ and $pA$ collisions at RHIC and LHC energies are estimated using the Colour Glass Condensate (CGC) formalism. We update previous predictions for the $p_T$ - spectra using the hybrid formalism of the CGC approach and two phenomenological models for the dipole - target scattering amplitude. We demonstrate that these models are able to describe the RHIC and LHC data for the hadron production in $pp$, $dAu$ and $pPb$ collisions at $p_T\le 20$ GeV. Moreover, we present our predictions for $⟨p_T⟩$ and demonstrate that the ratio $⟨p_T(y)⟩/⟨p_T(y=0)⟩$ decreases with the rapidity and has a behaviour similar to that predicted by hydrodynamical calculations.

Comments: 11 pages, 7 figures; revised version: new results for the average transverse momentum at partonic level added in fig. 4; Results and Discussion section has been improved and enlarged