Heavy flavor puzzle at RHIC: analysis of the underlying effects

Abstract

Suppressions of light and heavy flavor observables are considered to be excellent probes of QCD matter created in ultra-relativistic heavy ion collisions. Suppression predictions of quark and gluon jets appear to suggest a clear hierarchy according to which neutral pions should be more suppressed than D mesons, which in turn should be more suppressed than single electrons. However, joint comparison of neutral pion (light probe) and non-photonic single electron (heavy probe) suppression data at RHIC unexpectedly showed similar jet suppression for these two probes, which presents the well-known heavy flavor puzzle at RHIC. We here analyze which effects are responsible for this unexpected result, by using the dynamical energy loss formalism. We find that the main effect is a surprising reversal in the suppression hierarchy between neutral pions and D mesons, which is due to the deformation of the suppression patterns of light partons by fragmentation functions. Furthermore, we find that, due to the decay functions, the single electron suppression approaches the D meson suppression. Consequently, we propose that these two effects, taken together, provide a clear intuitive explanation of this longstanding puzzle.

6 pages, 6 figures

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Cited by in corpus (3)

• Evidence of Mass Ordering of Charm and Bottom Quark Energy Loss in Au+Au Collisions at RHIC
• Charm- and Bottom-Quark Production in Au$+$Au Collisions at $\sqrt{s_{{}_{NN}}}$ = 200 GeV
• Understanding mass hierarchy in collisional energy loss through heavy flavor data