Indications of Conical Emission of Charged Hadrons at the BNL Relativistic Heavy Ion Collider

TL;DR

This paper reports evidence of conical emission of charged hadrons in central Au+Au collisions at 200 GeV, observed through three-particle azimuthal correlations, indicating possible shockwave phenomena in quark-gluon plasma.

Contribution

It provides the first indication of conical emission in heavy-ion collisions at RHIC, with a measured emission angle independent of transverse momentum.

Findings

Conical emission observed in central Au+Au collisions.

Emission angle measured at approximately 1.37 degrees.

Dijet structures present in pp, d+Au, and peripheral Au+Au collisions.

Abstract

Three-particle azimuthal correlation measurements with a high transverse momentum trigger particle are reported for pp, d+Au, and Au+Au collisions at 200 GeV by the STAR experiment. Dijet structures are observed in pp, d+Au and peripheral Au+Au collisions. An additional structure is observed in central Au+Au data, signaling conical emission of correlated charged hadrons. The conical emission angle is found to be 1.37 +- 0.02(stat) +0.06-0.07(syst), independent of pt.