Your search

In authors or contributors
  • The Solenoidal Tracker at RHIC (STAR) experiment at the Relativistic Heavy Ion Collider reports new measurements of jet quenching based on the semi-inclusive distribution of charged-particle jets recoiling from direct photon (γdir) and neutral pion (π0) triggers in pp and central Au + Au collisions at √sNN = 200 GeV for triggers in the range 9 < ET trig < 20 GeV. The datasets have integrated luminosities of 3.9 nb−1 for Au + Au and 23 pb−1 for pp collisions. Jets are reconstructed using the anti-kT algorithm with resolution parameters R = 0.2 and 0.5. The large uncorrelated jet background in central Au + Au collisions is corrected using a mixed-event approach, which enables precise charged-particle jet measurements at low transverse momentum pch T,jet and large R. Recoil-jet distributions are reported in the range pch T,jet < 25 GeV/c. Comparison of the distributions measured in pp and Au + Au collisions reveals strong medium-induced jet yield suppression for R = 0.2 with markedly less suppression for R = 0.5. Comparison is also made to theoretical models incorporating jet quenching. These data provide new insight into the mechanisms underlying jet quenching and the angular dependence of medium-induced jet-energy transport and provide new constraints on modeling such effects. © 2025 American Physical Society

  • We report measurements of charmonium sequential suppression in Ru+Ru and Zr+Zr collisions at sNN=200 GeV with the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The inclusive yield ratio of ψ(2S) to J/ψ as a function of transverse momentum is reported, along with the centrality dependence of the double ratio, defined as the ψ(2S) to J/ψ ratio in heavy-ion collisions relative to that in p+p collisions. In the 0-80% centrality class, the double ratio is found to be 0.41±0.10 (stat)±0.03 (syst)±0.02 (ref), lower than unity with a significance of 5.6 standard deviations. This provides experimental evidence that ψ(2S) is significantly more suppressed than J/ψ in heavy-ion collisions at RHIC. This sequential suppression pattern seems to increase from peripheral to central collisions, but with no significant dependence on the transverse momentum. © 2026 American Physical Society.

Last update from database: 4/24/26, 4:15 PM (UTC)

Explore

Department

Resource type

Publication year

Resource language