Ultracentral Collisions of Small and Deformed Systems at RHIC

Douglas Wertepny, Jacquelyn Noronha-Hostler, Matthew Sievert, Skandaprasad Rao, Noah Paladino

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


We study a range of collision systems involving deformed ions and compare the elliptic and triangular flow harmonics produced in a hydrodynamics scenario versus a color glass condensate (CGC) scenario. For the hydrodynamics scenario, we generate initial conditions using TRENTO and work within a linear response approximation to obtain the final flow harmonics. For the CGC scenario, we use the explicit calculation of two-gluon correlations taken in the high-pT “(semi)dilute-(semi)dilute” regime to express the flow harmonics in terms of the density profile of the collision. We consider ultracentral collisions of deformed ions as a testbed for these comparisons because the difference between tip-on-tip and side-on-side collisions modifies the multiplicity dependence in both scenarios, even at zero impact parameter. We find significant qualitative differences in the multiplicity dependence obtained in the initial conditions+hydrodynamics scenario and the CGC scenario, allowing these collisions of deformed ions to be used as a powerful discriminator between models. We also find that sub-nucleonic fluctuations have a systematic effect on the elliptic and triangular flow harmonics which are most discriminating in 0–1% ultracentral symmetric collisions of small deformed ions and in 0–10% d197Au collisions. The collision systems we consider are 238U238U, d197Au, 9Be197Au, 9Be9Be, 3He3He, and 3He197Au.

Original languageEnglish
Article number121839
JournalNuclear Physics A
StatePublished - 1 Jan 2021

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


Dive into the research topics of 'Ultracentral Collisions of Small and Deformed Systems at RHIC'. Together they form a unique fingerprint.

Cite this