Measurements of azimuthal anisotropy of nonprompt D$^0$ mesons in PbPb collisions at $\sqrt{s_\mathrm{NN}}$ = 5.02 TeV

TL;DR

This study measures the azimuthal anisotropy of nonprompt D0 mesons in PbPb collisions at 5.02 TeV, revealing mass-dependent interactions of quarks with the quark-gluon plasma, and compares these with prompt meson results.

Contribution

It provides the first detailed comparison of azimuthal anisotropy between prompt and nonprompt D0 mesons, highlighting mass-dependent effects in quark-medium interactions.

Findings

Nonprompt D0 mesons have lower v2 and v3 magnitudes than prompt mesons.

The anisotropy shows weaker dependence on transverse momentum and centrality for nonprompt mesons.

Results agree with models including mass-dependent quark-medium interactions.

Abstract

Measurements of the elliptic ($v_2$) and triangular ($v_3$) azimuthal anisotropy coefficients are presented for D$^0$ mesons produced in b hadron decays (nonprompt D$^0$ mesons) in lead-lead collisions at $\sqrt{s_\mathrm{NN}}$ = 5.02 TeV. The results are compared with previously published charm meson anisotropies measured using prompt D$^0$ mesons. The data were collected with the CMS detector in 2018 with an integrated luminosity of 0.58 nb$^{-1}$. Azimuthal anisotropy is sensitive to the interactions of quarks with the hot and dense medium created in heavy ion collisions. Comparing results for prompt and nonprompt D$^0$ mesons can assist in understanding the mass dependence of these interactions. The nonprompt results show lower magnitudes of $v_2$ and $v_3$ and weaker dependences on the meson transverse momentum and collision centrality than those found for prompt D$^0$ mesons. The results are in agreement with theoretical predictions that include a mass dependence in the interactions of quarks with the medium.