February 24, 2023 / Berkeley Lab Nuclear Science Division News ~
Physicists in the STAR Collaboration have recently reported new evidence that production of an exotic state of matter in collisions of gold nuclei at the Relativistic Heavy Ion Collider (RHIC) – an atom-smasher at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory – can be “turned off” by lowering the collision energy. The “off” signal shows up as a sign change (from negative to positive) in data that describe “higher order” characteristics of the distribution of protons produced in these collisions. “This sign change is a robust indication, supported by first-principles calculations, that the formation of a quark-gluon plasma is turned off at RHIC’s lowest collision energy,” said Nu Xu, a senior scientist in Berkeley Lab’s Nuclear Science Division (NSD) and co-author on the study. Their findings, just published in Physical Review Letters, will help physicists map out the conditions of temperature and density under which the exotic matter, known as a quark-gluon plasma (QGP), can exist and identify key features of the phases of nuclear matter.
Read More:
Clear Sign that QGP Production ‘Turns Off’ at Low Energy
Higher order statistical analysis of protons emitted from wide range of gold-gold collision energies shows clear absence of a quark-gluon plasma (QGP) at the lowest energy
February 24, 2023 / Brookhaven National Laboratory Newsroom
Beam Energy Dependence of Fifth- and Sixth-Order Net-Proton Number Fluctuations in
Au + Au Collisions at RHIC
February 24, 2023 / B. E. Aboona et al. (STAR Collaboration) / Physical Review Letters
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PS News Contact: Marsha Fenner (MWFenner@lbl.gov)