Heavy flavor puzzle at LHC: a serendipitous interplay of jet suppression and fragmentation

TL;DR

The paper explains the heavy flavor puzzle at LHC by showing that the observed similar suppression of charged hadrons and D mesons results from a coincidental interplay of suppression and fragmentation patterns, not identical energy loss.

Contribution

The study introduces a new formalism to analyze jet suppression, revealing that the heavy flavor puzzle arises from specific suppression and fragmentation interplay, not equal parton energy loss.

Findings

The suppression patterns of light hadrons and D mesons are linked through a simple relationship.

The coincidence of suppression and fragmentation patterns simplifies interpretation of experimental data.

Different energy loss mechanisms for light and heavy quarks can produce similar suppression signatures.

Abstract

Both charged hadrons and D mesons are considered to be excellent probes of QCD matter created in ultra relativistic heavy ion collisions. Surprisingly, recent experimental observations at LHC show the same jet suppression for these two probes, which - contrary to pQCD expectations - may suggest similar energy losses for light quarks and gluons in QCD medium. We here use our recently developed energy loss formalism in a finite size dynamical QCD medium to analyze this phenomenon that we denote as the "heavy flavor puzzle at LHC". We show that this puzzle is a consequence of an unusual combination of the suppression and fragmentation patterns, and in fact does not require invoking the same energy loss for light partons. Furthermore, we show that this combination leads to a simple relationship between the suppressions of light hadrons and D mesons and the corresponding bare quark suppressions. Consequently, a coincidental matching of jet suppression and fragmentation allows considerably simplifying the interpretation of the corresponding experimental data.