(2+1)味格点QCD中物理夸克质量下基于无偏指数重整化的QCD过渡温度与曲率系数
The QCD crossover temperature and curvature coefficient from unbiased exponential resummation at physical quark masses in (2+1)-flavor lattice QCD
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中文总结 AI 辅助
本研究首次将无偏指数重整化方法用于(2+1)味格点QCD的零重子化学势赝临界温度测定，得到与此前结果一致的数值，并验证该方法可作为探测小有限重子密度下QCD过渡的补充手段。
中文摘要 AI 辅助
我们首次将无偏指数重整化方法应用于重子化学势$μ_B$为零时QCD赝临界温度$T_{\rm pc}$的测定。通过重构有限密度下的重子数磁化率$χ_2^B$，我们定义了两个热导数可观测量，其峰值位置给出$T_{\rm pc}^T=160.2(4)(3)$ MeV与$T_{\rm pc}^C=158.1(5)(3)$ MeV。我们还表明，由四阶重子数磁化率$χ_4^B$的峰值得到的赝临界温度$T_{\rm pc}^χ$，与上述测定结果及此前基于泰勒展开的格点QCD结果[Bollweg:2022Pade]一致。此外，我们证明$χ_4^B$与$χ_2^B$的热导数之间的标度关系[Bollweg:2022fqq]，可在对应赝临界温度下给出相互一致的领头阶二阶曲率系数$κ_2^B$估计值。对赝临界温度的$μ_B$依赖性的直接分析，给出了曲率的独立但约束性弱得多的测定结果，其在统计上与基于标度的估计值一致。这些结果证明了无偏指数重整化与预期标度行为的一致性，并确立其作为探测小有限重子密度下QCD过渡的补充方法。
英文摘要
We present the first application of the unbiased exponential resummation method to the determination of the QCD pseudocritical temperature $T_{\rm pc}$ at vanishing baryon chemical potential $μ_B$. By reconstructing the finite-density baryon number susceptibility $χ_2^B$, we define two thermal-derivative observables whose peak positions yield $T_{\rm pc}^T=160.2(4)(3)$ MeV and $T_{\rm pc}^C=158.1(5)(3)$ MeV. We also show that the pseudocritical temperature, $T_{\rm pc}^χ$ obtained from the peak of the fourth-order baryon number susceptibility $χ_4^B$ is consistent with these determinations and with previous lattice-QCD results based on Taylor expansions \cite{Bollweg:2022Pade}. Further, we demonstrate that scaling relations \cite{Bollweg:2022fqq} between $χ_4^B$ and the thermal derivatives of $χ_2^B$ yield mutually consistent estimates of the leading second order curvature coefficient $κ_2^B$ at the corresponding pseudocritical temperatures. A direct analysis of the $μ_B$ dependence of the pseudocritical temperatures provides an independent but substantially less constrained determination of the curvature, which remains statistically consistent with the scaling-based estimates. These results demonstrate the consistency of unbiased exponential resummation with the expected scaling behavior and establish it as a complementary approach for probing the QCD crossover at small finite baryon density.
