The decay constants f D and fDs $$ {f}_{D_s} $$ in the continuum limit of N f = 2 + 1 domain wall lattice QCD

Abstract

Abstract We present results for the decay constants of the D and D s mesons computed in lattice QCD with N f = 2 + 1 dynamical flavours. The simulations are based on RBC/UKQCD’s domain wall ensembles with both physical and unphysical light-quark masses and lattice spacings in the range 0.11-0.07 fm. We employ the domain wall discretisation for all valence quarks. The results in the continuum limit are f D = 208.7(2.8)stat(− 1.8+ 2.1)sysMeV and fDs=246.41.3stat−1.9+1.3sysMeV $$ {f}_{D_s}=246.4{(1.3)}_{\mathrm{stat}}{\left({}_{-1.9}^{+1.3}\right)}_{\mathrm{sys}}\mathrm{M}\mathrm{e}\mathrm{V} $$ and fDs=fD=1.66777stat−43+57sys $$ {f}_{D_s}={f}_D=1.667{(77)}_{\mathrm{stat}}{\left({}_{-43}^{+57}\right)}_{\mathrm{sys}} $$. Using these results in a Standard Model analysis we compute the predictions |V cd | = 0.2185(50)exp(− 37+ 35)lat and |V cs | = 1.011(16)exp(− 9+ 4)lat for the CKM matrix elements.

Keywords

• Heavy Quark Physics
• Lattice QCD
• Lattice Quantum Field Theory
• Quark Masses and SM Parameters