Rapp R, Shuryak E V
Department of Physics and Astronomy, State University of New York, Stony Brook, New York 11794-3800.
Phys Rev Lett. 2001 Apr 2;86(14):2980-3. doi: 10.1103/PhysRevLett.86.2980.
We argue that the observed antiproton production in heavy-ion collisions at CERN-SPS energies can be understood if (contrary to most sequential scattering approaches) the backward direction in the process pP<-->n(pi) (with n = 5-6) is consistently accounted for within a thermal framework. Employing the standard picture of subsequent chemical and thermal freezeout, which induces an oversaturation of pion number with associated chemical potentials of mu(pi) approximately 60-80 MeV, enhances the backward reaction substantially. The resulting rates turn out to be large enough to maintain an antiproton abundance at thermal freezeout in accordance with the measured p/p ratio in Pb(158A GeV)+Pb collisions.
我们认为，如果（与大多数顺序散射方法相反）在热框架内一致地考虑过程pP<-->n(π)（n = 5 - 6）中的向后方向，那么在欧洲核子研究组织超级质子同步加速器（CERN - SPS）能量下重离子碰撞中观测到的反质子产生就能得到理解。采用随后化学和热冻结的标准图景，这会导致π介子数过饱和以及相关的化学势μ(π)约为60 - 80兆电子伏特，这会显著增强向后反应。结果表明，由此产生的速率足够大，能够根据在铅（158A吉电子伏特）+铅碰撞中测量的p/p比率，在热冻结时维持反质子丰度。
