Analyzing radial flow features in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>p</mml:mi></mml:math>-Pb and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>p</mml:mi></mml:math>-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>p</mml:mi></mml:math>collisions at several TeV by studying identified-particle production with the event generator EPOS3

Abstract

Experimental transverse momentum spectra of identified particles in $p$-Pb collisions at 5.02 TeV show many similarities to the corresponding Pb-Pb results, the latter ones usually being interpreted in terms of hydrodynamic flow. We analyze these data using epos3, an event generator based on a $3\mathrm{D}+1$ viscous hydrodynamical evolution starting from flux-tube initial conditions, which are generated in the Gribov-Regge multiple scattering framework. An individual scattering is referred to as Pomeron, identified with a parton ladder, eventually showing up as flux tubes (or strings). Each parton ladder is composed of a perturbative QCD hard process, plus initial- and final-state linear parton emission. Nonlinear effects are considered by using saturation scales ${Q}_{s}$, depending on the energy and the number of participants connected to the Pomeron in question. We compute transverse momentum (${p}_{t}$) spectra of pions, kaons, protons, lambdas, and $\ensuremath{\Xi}$ baryons in $p$-Pb and $p$-$p$ scattering, compared to experimental data and many other models. In this way we show in a quantitative fashion that $p$-Pb data (and even $p$-$p$ ones) show the typical ``flow effect'' of enhanced particle production at intermediate ${p}_{t}$ values, more and more visible with increasing hadron mass.