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arXiv 1508.02178hep-lat
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格点量子色动力学对粲偶素和粲奇异介子的势描述

Potential description of charmonium and charmed-strange mesons from lattice QCD

Taichi Kawanai, Shoichi Sasaki

摘要:

利用2+1味格点量子色动力学模拟方法,在最轻π介子质量($M_π\approx 156(7)$ ~MeV)下产生的PACS-CS规范组态,格点截断为$a^{-1}\approx 2.2$ GeV,空间体积为$(3~{\rm fm})^3$,计算了粲偶素和粲奇异介子的自旋-自旋夸克间相互作用势.对于粲夸克,我们使用相对论重夸克(RHQ)作用量和微调的RHQ参数,这紧密地再现了$1S$粲偶素的实验自旋平均质量和超精细分裂。夸克间势和夸克动力学质量是重-重和重-轻介子势描述中的重要组成部分,由等时Bethe-Salpeter(BS)振幅确定。由$1S$粲偶素($η_c$和$J/ψ$介子)的BS波函数得到粲偶素势,由$D_s$和$D_s^{\ast}$重轻介子计算粲奇异势.然后,我们使用由此产生的势和夸克质量作为纯理论输入,以解决非相对论薛定谔方程计算粲偶素和粲奇介子的可达能级没有未知参数。低于$D\bar{D}$和$DK$阈值的所得光谱与公认的实验数据非常一致。

英文摘要:

We present spin-independent and spin-spin interquark potentials for the charmonium and charmed-strange mesons, which are calculated in 2+1 flavor lattice QCD simulations using the PACS-CS gauge configurations generated at the lightest pion mass ($M_π\approx 156(7)$~MeV) with a lattice cutoff of $a^{-1}\approx 2.2$ GeV and a spatial volume of $(3~{\rm fm})^3$. For the charm quark, we use a relativistic heavy quark (RHQ) action with fine tuned RHQ parameters, which closely reproduce both the experimental spin-averaged mass and hyper-fine splitting of the $1S$ charmonium. The interquark potential and the quark kinetic mass, both of which are key ingredients within the potential description of heavy-heavy and heavy-light mesons, are determined from the equal-time Bethe-Salpeter (BS) amplitude. The charmonium potentials are obtained from the BS wave function of $1S$ charmonia ($η_c$ and $J/ψ$ mesons), while the charmed-strange potential are calculated from the $D_s$ and $D_s^{\ast}$ heavy-light mesons. We then use resulting potentials and quark masses as purely theoretical inputs so as to solve the nonrelativistic Schrödinger equation for calculating accessible energy levels of charmonium and charmed-strange mesons without unknown parameters. The resultant spectra below the $D\bar{D}$ and $DK$ thresholds excellently agree with well-established experimental data.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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