Probing the profile of bulk matter in p+Pb collisions via directed flow of heavy quarks

TL;DR

This study uses the AMPT model to analyze the directed flow of light and heavy quarks in p+Pb collisions at 5.02 TeV, revealing significant differences in their flow patterns that can probe initial matter distribution.

Contribution

It predicts the directed flow of heavy and light quarks in p+Pb collisions, highlighting the potential to explore initial matter density and collective dynamics.

Findings

Heavy quark $v_1$ is 15 times larger than light quarks in the Pb-going direction.

Light and heavy quark $v_1$ show non-trivial $p_T$ dependence.

Predictions align with existing light-quark flow measurements.

Abstract

The asymmetric initial geometry in p+Pb collisions provide an opportunity to probe the initial matter distribution in these collisions. Using A Multi-Phase Transport (AMPT) model, we have studied the production of light and heavy quark particles in p+Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV. The pseudo-rapidity density (dN/d$\eta$) and elliptic flow ($v_{2}$) of light-quark particles from AMPT reasonably agrees with the measurements by ALICE. We predicted the directed flow of light and heavy quarks in p+Pb collisions. The $v_{1}$ of both light and heavy-quark mesons show a non-trivial $p_{T}$ dependence in p- and Pb-going directions. When integrated over the transverse momentum range 0 $ < p_{T} < $5 GeV/c, the magnitude of heavy quark directed flow ($v_{1}$) is found to be 15 times larger than the light quark species in the Pb-going direction while the same in the p-going direction are comparable. The light and heavy quarks $v_{1}$ may offer the possibility to probe the initial matter density as well as the collective dynamics in p+Pb collisions