Heavy quarkonia in quark-gluon plasma
Heavy quarkonia in quark-gluon plasma
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DOI：
10.1103/physrevc.72.034906
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发表时间：
2004-08
影响因子：
3.1
通讯作者：
C. Wong
中科院分区：
文献类型：
--
作者：
C. Wong
Q在猝灭的QCD中，我们研究了夸克-胶子等离子体中重夸克的结合能和波函数。通过在一个简化的模型中最小化宏势，我们发现从总的内能U1减去胶子内能贡献可以得到合适的色单重态Q-Q势。我们在局域能量密度近似下进行减法，在局域能量密度近似下，胶子能量密度可以通过夸克-胶子等离子体状态方程与局域胶子压强相关联。在这个近似下，我们发现对于T-∼T_c，合适的色单重态Q-Q势近似为F_1，在高温下变为3F_1+1U_1。在这个势模型中，J/ψ在相变温度T_c以上弱结合，在1.62℃以上自发解离，而χ_c和ψ�在夸克-胶子等离子体中是非束缚的。底态ϒ，χb、ϒ�束缚在夸克胶子等离子体中，分别在4.1T、1.18T和1.38T下解离。为了比较，我们也用自由能F1或总内能U1作为Q-Q势来计算其他模型中的重夸克结合能。比较表明，采用新的Q-Q势的模型给出的离解温度与谱函数分析得到的离解温度最接近。我们计算了σ(g+J/ψ→c+‘c)的截面及其逆过程，通过在夸克-胶子等离子体中c和c的重组来确定J/ψ的解离宽度和J/ψ的产生率。
Q in quenched QCD, we study the binding energies and wave functions of heavy quarkonia in a quark-gluon plasma. By minimizing the grand potential in a simplified schematic model, we find that the proper color-singlet Q- ¯ Q potential can be obtained from the total internal energy U1 by subtracting the gluon internal energy contributions. We carry out this subtraction in the local energy-density approximation in which the gluon energy density can be related to the local gluon pressure by the quark-gluon plasma equation of state. We find in this approximation that the proper color-singlet Q- ¯ Q potential is approximately F1 for T ∼ Tc and it changes to 3 F1 + 1 U1 at high temperatures. In this potential model, the J/ ψ is weakly bound above the phase-transition temperature Tc, and it dissociates spontaneously above 1.62Tc, whereas χc and ψ � are unbound in the quark-gluon plasma. The bottomium states ϒ, χb ,a ndϒ � are bound in the quark-gluon plasma and they dissociate at 4.1Tc, 1.18Tc, and 1.38Tc respectively. For comparison, we evaluate the heavy quarkonium binding energies also in other models using the free energy F1 or the total internal energy U1 as the Q- ¯ Q potential. The comparison shows that the model with the new Q- ¯ Q potential proposed here gives dissociation temperatures that agree best with those from spectral function analyses. We evaluate the cross section for σ (g + J/ ψ → c + ¯ c) and its inverse process to determine the J/ ψdissociation width and the rate of J/ ψ production by recombining c and ¯ c in the quark-gluon plasma.