Surprising Long-Range Correlations Found in Proton-lead Collisions at the LHC

Dragos Velicanu, Massachusetts Institute of Technology

Photo of Dragos Velicanu

This poster will discuss the recent results showing surprisingly strong long-range correlations between charged particles produced in ultra-relativistic proton-lead collisions with the CMS experiment at the Large Hadron Collider (LHC). Proton-nucleus collisions have been used as references for nucleus-nucleus collisions where the qualitative and quantitative differences observed in experiment indicate the observable differences between matter heated to ultrahot temperatures, referred to as a quark-gluon plasma, and independent collisions between the pieces of the nucleus without the heating effect. Up to now long-range azimuthal correlations have only been observed in nucleus-nucleus collisions and not in proton-nucleus collisions, and have been regarded as one of the compelling pieces of evidence that a quark-gluon plasma is only formed when large, hot systems collide and have a chance to thermalize. However, I will show how the proton-nucleus collisions recently recorded at the LHC exhibit a long-range correlation both qualitatively and quantitatively similar to those observed in nucleus-nucleus collisions and discuss the implications of this.

Abstract Author(s): Dragos Velicanu