On a lattice with 2+1-flavor dynamical domain-wall fermions at the physical pion mass, we calculate the decay constants of $D_{s}^{(*)}$, $D^{(*)}$ and $ϕ$. The lattice size is $48^3\times96$, which corresponds to a spatial extension of $\sim5.5$ fm with the lattice spacing $a\approx 0.114$ fm. For the valence light, strange and charm quarks, we use overlap fermions at several mass points close to their physical values. Our results at the physical point are $f_D=213(5)$ MeV, $f_{D_s}=249(7)$ MeV, $f_{D^*}=234(6)$ MeV, $f_{D_s^*}=274(7)$ MeV, and $f_ϕ=241(9)$ MeV. The couplings of $D^*$ and $D_s^*$ to the tensor current ($f_V^T$) can be derived, respectively, from the ratios $f_{D^*}^T/f_{D^*}=0.91(4)$ and $f_{D_s^*}^T/f_{D_s^*}=0.92(4)$, which are the first lattice QCD results. We also obtain the ratios $f_{D^*}/f_D=1.10(3)$ and $f_{D_s^*}/f_{D_s}=1.10(4)$, which reflect the size of heavy quark symmetry breaking in charmed mesons. The ratios $f_{D_s}/f_{D}=1.16(3)$ and $f_{D_s^*}/f_{D^*}=1.17(3)$ can be taken as a measure of SU(3) flavor symmetry breaking.
Estimate of the charmed 0-- hybrid meson spectrum from quenched lattice QCD
我们从猝灭的格点量子色动力学计算了奇异量子数JPC=1-+，0+-和0--的粲杂化介子cbar c g的基态质量.由于从噪声中提取高胶子激发的困难，格点模拟从未提供过0-杂化介子谱。我们在各向异性晶格上采用了改进的规范和费米子作用，这大大减少了晶格伪影，并产生了非常好的信号。数据外推到连续极限，有限尺寸效应在井控制下。对于1+和0+杂化介子，其基态质量分别为4.405（38）GeV和4.714（52）GeV.我们首次从格点量子色动力学预言0-的基态质量为5.883（146）GeV。
