UPTON, NY-Particles emerging from even the lowest energy collisions of small deuterons with large heavy nuclei at the Relativistic Heavy Ion Collider-a U.S. Department of Energy Office of Science User Facility for nuclear physics research at DOE’s Brookhaven National Laboratory-exhibit behavior scientists associate with the formation of a soup of quarks and gluons, the fundamental building blocks of nearly all visible matter.
These results from RHIC’s PHENIX experiment suggest that these small-scale collisions might be producing tiny, short-lived specks of matter that mimics what the early universe was like nearly 14 billion years ago, just after the Big Bang.
The new findings-correlations in the way particles emerge from the collisions that are consistent with what physicists have observed in the more energetic large-ion collisions-add to a growing body of evidence from RHIC and Europe’s Large Hadron Collider that QGP may be created in smaller systems as well.
One of the earliest signs that RHIC’s collisions of two gold ions were creating QGP came in the form of “Collective flow” of particles. Over a period of about five weeks in 2016, the PHENIX team explored collisions of deuterons with gold ions at four different energies.
“Thanks to the versatility of RHIC and the ability of the staff in Brookhaven’s Collider-Accelerator Department to quickly switch and tune the machine for different collision energies, PHENIX was able to record more than 1.5 billion collisions in this short period of time,” Velkovska said.
For the paper submitted to PRC, Darren McGlinchey, a PHENIX collaborator from Los Alamos National Laboratory, led an analysis of how particles emerged along the elliptical plane of the collisions as a function of their momentum, how central the collisions were, and how many particles were produced.