论文标题
$ n_f = 3+1 $ qcd的比例设置
Scale setting for $N_f=3+1$ QCD
论文作者
论文摘要
我们介绍了一组新的量规配置的比例设置，该量规配置使用$ n_f = 3+1 $ Wilson Quarks，其在巨大的O（$ A $）改进方案中具有非扰动的三叶草系数。这三个光夸克是堕落的，其质量的总和等于其在性质上的价值，并且魅力夸克具有物理质量。我们在时间方向上使用开放的边界条件，以避免在小晶格间距处进行拓扑结冰的问题，并扭曲质量重新加权，以提高模拟的稳定性。低能魅力的魅力的解耦使我们能够通过测量低能量$ t_0^\ star/a^2 $的值来设置量表，这是我们的群众点的流量比例$ t_0 $，并将其与$ n_f = 2+1 $的物理单位进行比较。我们介绍算法设置和调整过程的详细信息，并用两个晶格间距a = 0.054 fm和a = 0.043 fm给出合奏的裸参数。我们讨论有限的体积效应和晶格伪像，并为炭谱呈现物理效果。尤其是$η_c$和$ j/ψ$介子之间的超细分裂与其物理价值非常吻合。
We present the scale setting for a new set of gauge configurations generated with $N_f=3+1$ Wilson quarks with a non-perturbatively determined clover coefficient in a massive O($a$) improvement scheme. The three light quarks are degenerate, with the sum of their masses being equal to its value in nature and the charm quark has its physical mass. We use open boundary conditions in time direction to avoid the problem of topological freezing at small lattice spacings and twisted-mass reweighting for improved stability of the simulations. The decoupling of charm at low energy allows us to set the scale by measuring the value of the low-energy quantity $t_0^\star/a^2$, which is the flow scale $t_0$ at our mass point, and comparing it to an $N_f=2+1$ result in physical units. We present the details of the algorithmic setup and tuning procedure and give the bare parameters of ensembles with two lattice spacings a=0.054 fm and a=0.043 fm. We discuss finite volume effects and lattice artifacts and present physical results for the charmonium spectrum. In particular the hyperfine splitting between the $η_c$ and $J/ψ$ mesons agrees very well with its physical value.
