论文标题
炭状状态的脾气
Gluons in charmoniumlike states
论文作者
论文摘要
通过在晶格上的QCD能量量张量（EMT）的分解来研究炭状状态的质量成分。夸克质量贡献$ \ langle h_m \ rangle $和动量分数$ \ langle x \ langle x \ rangle $ valence charm Quark and angiquark和Angiquark的计算是针对常规$ 1S，1p，1d $ charmonia和Exotic $ 1^{ - +charmoniumliep countation the $ charmonium light conforation the $ charmonium light coundation $ charmonium light conforation $ n _ RBC/UKQCD合作。发现这些状态的$ \ langle h_m \ rangle $彼此接近，大约2.0至2.2 GEV，这意味着这些州之间的质量分裂几乎来自QCD跟踪异常的GLUON贡献。 $ 1^{ - +} $状态的$ \ langle x \ rangle $仅约0.55，而常规charmonia中的$左右约为0.7至0.8。这种差异表明，在$ 1^{ - +} $ charmoniumliumike状态下的光夸克和胶子的比例明显大于常规状态。
The mass components of charmoniumlike states are investigated through the decomposition of QCD energy-momentum tensor (EMT) on lattice. The quark mass contribution $\langle H_m\rangle$ and the momentum fraction $\langle x\rangle$ of valence charm quark and antiquark are calculated for conventional $1S,1P,1D$ charmonia and the exotic $1^{-+}$ charmoniumlike state, based on the $N_f=2+1$ gauge configurations generated by the RBC/UKQCD collaboration. It is found that $\langle H_m\rangle$ is close to each other and around 2.0 to 2.2 GeV for these states, which implies that the mass splittings among these states come almost from the gluon contribution of QCD trace anomaly. The $\langle x\rangle$ of the $1^{-+}$ state is only around 0.55, while that in conventional charmonia is around 0.7 to 0.8. This difference manifests that the proportion of light quarks and gluons in the $1^{-+}$ charmoniumlike state is significantly larger than conventional states.
