Cold-nuclear-matter effcts on heavy-quark production in d+Au collisions at sqrt(s_NN)=200 GeV

TL;DR

This study measures heavy-flavor electron production in d+Au and p+p collisions at 200 GeV, revealing cold nuclear matter effects like enhancement consistent with the Cronin effect, and comparing these to light-flavor mesons to understand nuclear modifications.

Contribution

It provides the first evidence of mass-dependent cold-nuclear-matter effects on heavy-flavor production at RHIC energies, extending the understanding of nuclear modifications to heavy mesons.

Findings

Evidence of enhancement in heavy-flavor electrons in central d+Au collisions.

Extension of the Cronin effect to heavy-D-meson family.

Differences in cold-nuclear-matter effects between light and heavy mesons.

Abstract

The PHENIX experiment has measured electrons and positrons at midrapidity from the decays of hadrons containing charm and bottom quarks produced in d+Au and p+p collisions at sqrt(s_NN)=200 GeV at the Relativistic Heavy Ion Collider, in the transverse-momentum range 0.85 < pT < 8.5 GeV/c. In central d+Au collisions, the nuclear modification factor R_dA at 1.5 < pT < 5 GeV/c displays evidence of enhancement of these electrons, relative to those produced in p+p collisions, and shows that the mass-dependent Cronin enhancement observed at RHIC extends to the heavy-D-meson family. A comparison with the neutral-pion data suggests that the difference in cold-nuclear-matter effects on light- and heavy-flavor mesons could contribute to the observed differences between the pi0 and heavy-flavor-electron nuclear modification factor R_AA.