We compute the baryonic screening masses of the nucleon and of its negative parity partner in thermal QCD with massless quarks for a wide range of temperatures, from GeV up to ∼160 GeV. The computation is performed by Monte Carlo simulations of lattice QCD with -improved Wilson fermions by exploiting a recently proposed strategy to study non-perturbatively QCD at very high temperature. Very large spatial extensions are considered in order to have negligible finite volume effects. For each temperature we have simulated 3 or 4 values of the lattice spacing, so as to perform the continuum limit extrapolation with confidence at a few permille accuracy. The degeneracy of the positive and negative parity-state screening masses, expected from Ward identities associated to non-singlet axial transformations, provides further evidence for the restoration of chiral symmetry in the high temperature regime of QCD. In the entire range of temperatures explored, the baryonic masses deviate from the free theory result, , by 4–8%. The contribution due to the interactions is clearly visible up to the highest temperature considered, and cannot be explained by the expected leading behavior in the QCD coupling constant over the entire range of temperatures explored.

中文翻译：

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高温 QCD 中的重子屏蔽质量


我们使用无质量夸克在热 QCD 中计算核子及其负宇称伙伴的重子屏蔽质量，温度范围从 GeV 到~160 GeV。通过利用最近提出的研究非常高温下非微扰 QCD 的策略，通过使用改进的威尔逊费米子对晶格 QCD 进行蒙特卡罗模拟来执行计算。考虑非常大的空间延伸，以便可以忽略有限体积效应。对于每个温度，我们模拟了 3 或 4 个晶格间距值，以便以几分之一的精度充满信心地执行连续极限外推。根据与非单线轴变换相关的沃德恒等式预计，正负宇称态屏蔽质量的简并性为 QCD 高温状态下手性对称性的恢复提供了进一步的证据。在探索的整个温度范围内，重子质量与自由理论结果 的偏差为 4-8%。在所考虑的最高温度下，由于相互作用而产生的贡献是清晰可见的，并且不能通过在整个探索的温度范围内 QCD 耦合常数的预期主导行为来解释。