Proceedings of RIKEN BNL Research Center Workshop on Baryon Dynamics at RHIC, March 28-30, 2002, Brookhaven National Laboratory.

Gyulassy, M. ; Kharzeev, D. ; Xu, N.

Brookhaven National Laboratory

关键词: Extrapolation;    Charged Particles;    Hydrodynamics;    Gluons;    Anisotropy;   

DOI  :  10.2172/801022
RP-ID  :  BNL--52669
RP-ID  :  AC02-98CH10886
RP-ID  :  801022

美国|英语

来源: UNT Digital Library

【 摘 要 】

One of the striking observations at RHIC is the large valence baryon rapidity density observed at mid rapidity in central Au+Au at 130 A GeV. There are about twice as many valence protons at mid-rapidity than predicted based on extrapolation from p+p collisions. Even more striking PHENIX observed that the high pt spectrum is dominated by baryons and anti-baryons. The STAR measured event anisotropy parameter v2 for lambdas are as high as charged particles at pt {approx} 2.5 GeV/c. These are completely unexpected based on conventional pQCD parton fragmentation phenomenology. One exciting possibility is that these observables reveal the topological gluon field origin of baryon number transport referred to as baryon junctions. Another is that hydrodynamics may apply up to high pt in A+A. There is no consensus on what are the correct mechanisms for producing baryons and hyperons at high pt and large rapidity shifts and the new RHIC data provide a strong motivation to hold a meeting focusing on this class of observables. The possible role of junctions in forming CP violating domain walls and novel nuclear bucky-ball configurations would also be discussed. In this workshop, we focused on all measured baryon distributions at RHIC energies and related theoretical considerations. To facilitate the discussions, results of heavy ion collisions at lower beam energies, results from p+A /p+p/e+e collisions were included. Some suggestions for future measurements have been made at the workshop.