Roberge-Weiss transitions at different center symmetry breaking patterns in a Z3-QCD model
Roberge-Weiss transitions at different center symmetry breaking patterns in a Z3-QCD model
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Z3-QCD 模型中不同中心对称破缺模式下的 Roberge-Weiss 跃迁
DOI：
10.1103/physrevd.100.074026
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发表时间：
2019
影响因子：
5
通讯作者：
Zhao Zhang
中科院分区：
文献类型：
--
作者：
Xiu-Fei Li;Zhao Zhang
我们利用Z3-QCD模型研究了Roberge-Weiss(RW)相变与中心对称性破缺的关系。我们采用依赖于味的夸克虚化学势，即(μu，μd，μS)/It=(θ-2πC/3，θ，θ+2πC/3)，C∈[0，1]。当C≠1和/或夸克质量为非简并质量时，RW周期得到了保证，Z3-QCD的中心对称性被明显破坏。对于Nf=3和C≠1，RW相变发生在θ=θRW=(2k+1)π/3(k∈Z)处，并且随着C的减小而变强；当C=1时，当Nf=2+1时，θRW变为2kπ/3，而当Nf=1+2时，RW相变保持在(2k+1)π/3；在这两种情况下，RW相变都随着质量失配的增加而增强。对于其他的C≠0情形，θRW不是π/3的整数倍。我们发现RW相变对C偏离1比质量非简并更敏感，因此C=0的传统RW相变的强度最强。研究了RW终点的性质及其对退禁闭转变的影响。
We study how the Roberge-Weiss (RW) transition depends on the pattern of center symmetry breaking using a Z3-QCD model. We adopt flavor-dependent quark imaginary chemical potentials, namely, (μu,μd,μs)/iT=(θ-2πC/3,θ,θ+2πC/3) with C∈[0,1]. The RW periodicity is guaranteed and the center symmetry of Z3-QCD is explicitly broken when C≠1 and/or quark masses are nondegenerate. For Nf=3 and C≠1, the RW transition occurs at θ=θRW=(2k+1)π/3(k∈Z), which becomes stronger with decrease of C. When C=1, the θRW turns into 2kπ/3 for Nf=2+1, but keeps (2k+1)π/3 for Nf=1+2; in both cases, the RW transitions get stronger with the mass mismatch. For other C≠0 cases, the θRW’s are not integral multiples of π/3. We find that the RW transition is more sensitive to the deviation of C from one compared to the mass nondegeneracy, and thus the strength of the traditional RW transition with C=0 is the strongest. The nature of RW end points and its implications to deconfinement transition are investigated.