论文标题
Lattice QCD + QED的Charmonium Properties：超精细分裂，$ J/ψ$ Leptonic宽度，Charm Quark Mass和$A_μ^C $
Charmonium properties from lattice QCD + QED: hyperfine splitting, $J/ψ$ leptonic width, charm quark mass and $a_μ^c$
论文作者
论文摘要
我们已经执行了第一个$ N_F = 2+1+1 $晶格QCD计算地面charmonium Meson的属性（质量和衰减常数）。我们的计算使用HISQ操作来生成Quark-line连接的两点相关功能在MILC GLUON场配置上，其中包括$ u/d $ Quark群众，将$ c $ quark质量从$ m_ {j/ψ}调整为$ c $ quark质量，包括$ c $ c $ quark Quark Quark Quark Quark Quark Quark Quark Quark Quark Quark Quark的效果。我们获得$ m_ {j/ψ} -m_ {η_c} $（连接）= 120.3（1.1）MEV，并将实验的差异解释为对其衰减的$ m_ {η_c} $的影响，从晶格计算中缺少。这使我们能够确定$Δm_{η_c}^{\ Mathrm {annihiln}} $ =+7.3（1.2）MEV，首次给出其值。我们的结果$ f_ {j/ψ} = $ 0.4104（17）GEV，给出$γ（j/ψ\ rightarrow e^+e^ - ）$ = 5.637（49）keV，但现在比实验更准确。同时，我们改进了$ c $ quark质量的确定，包括Quenched Qed的影响$ \ overline {M} _C（3 \，\ Mathrm {gev}）$ = 0.9841（51）GEV。我们还使用了矢量charmonium电流 - 电流相关器的时间表来改善$ c $ quark HVP对MUON异常磁矩的贡献的晶格QCD结果。我们获得了$a_μ^c = 14.638（47）\ times 10^{ - 10} $，比使用从$ r（e^+e^ - \ rightArrow \ mathrm {hadrons}上提取的一些实验数据中提取的矩提取的矩提取的矩，该值比得出的值高2.5 $σ$。 $a_μ^c $的此值包括我们确定QED对此数量的效果的确定，$ΔA_μ^C = 0.0313（28）\ times 10^{ - 10} $。
We have performed the first $n_f = 2+1+1$ lattice QCD computations of the properties (masses and decay constants) of ground-state charmonium mesons. Our calculation uses the HISQ action to generate quark-line connected two-point correlation functions on MILC gluon field configurations that include $u/d$ quark masses going down to the physical point, tuning the $c$ quark mass from $M_{J/ψ}$ and including the effect of the $c$ quark's electric charge through quenched QED. We obtain $M_{J/ψ}-M_{η_c}$ (connected) = 120.3(1.1) MeV and interpret the difference with experiment as the impact on $M_{η_c}$ of its decay to gluons, missing from the lattice calculation. This allows us to determine $ΔM_{η_c}^{\mathrm{annihiln}}$ =+7.3(1.2) MeV, giving its value for the first time. Our result of $f_{J/ψ}=$ 0.4104(17) GeV, gives $Γ(J/ψ\rightarrow e^+e^-)$=5.637(49) keV, in agreement with, but now more accurate than experiment. At the same time we have improved the determination of the $c$ quark mass, including the impact of quenched QED to give $\overline{m}_c(3\,\mathrm{GeV})$ = 0.9841(51) GeV. We have also used the time-moments of the vector charmonium current-current correlators to improve the lattice QCD result for the $c$ quark HVP contribution to the anomalous magnetic moment of the muon. We obtain $a_μ^c = 14.638(47) \times 10^{-10}$, which is 2.5$σ$ higher than the value derived using moments extracted from some sets of experimental data on $R(e^+e^- \rightarrow \mathrm{hadrons})$. This value for $a_μ^c$ includes our determination of the effect of QED on this quantity, $δa_μ^c = 0.0313(28) \times 10^{-10}$.
