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Sensitivity of heavy-quark dipolar flow to its initial spatial distributions in Cu+Au collisions

Ankit Kumar Panda*

Tribhuban Parida†

  • *Contact author: ankitkumarpanda932@gmail.com
  • †Contact author: tribhu.451@gmail.com
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Phys. Rev. C 114, 034909 – Published 11 September, 2026

DOI: https://doi.org/10.1103/nrkh-pmwk

Abstract

We investigate charm-quark dynamics in asymmetric Cu+Au collisions at top energies available at the BNL Relativistic Heavy Ion Collider using a Langevin approach embedded in a realistic hydrodynamic background. The intrinsic asymmetry of the colliding nuclei leads to a spatially lopsided initial energy-density profile, which generates a dipolar flow structure in the transverse plane even at midrapidity. As charm quarks propagate through this medium, they acquire a finite directed flow, v1. We find that the pT-integrated heavy-quark v1 is approximately an order of magnitude larger than that of charged hadrons. In addition, the pT-differential v1 exhibits strong sensitivity to the initial spatial distribution of heavy quarks, highlighting the potential impact of preequilibrium modifications of the heavy-quark phase-space distribution on final-state anisotropies. Beyond geometric effects, v1 also provides direct sensitivity to medium interactions through the temperature-dependent drag coefficient. Its pronounced dependence on this transport input indicates that precision measurements of heavy-flavor directed flow could place meaningful constraints on heavy-quark transport coefficients, thereby improving Langevin-based descriptions and predictive power for heavy-flavor observables in heavy-ion collisions.

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Outline

Information

Phys. Rev. C 114, 034909– Published 11 September, 2026
  • Received 30 May 2026
  • Revised 7 August 2026
  • Accepted 28 August 2026
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