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We determine the masses and decay constants of pseudoscalar mesons $ D $, $ D_s $, and $ K $ in quenched lattice QCD with exact chiral symmetry. For 100 gauge configurations generated with single-plaquette action at $ beta = 6.1 $ on the $ 20^3 times 40 $ lattice, we compute point-to-point quark propagators for 30 quark masses in the range $ 0.03 le m_q a le 0.80 $, and measure the time-correlation functions of pseudoscalar and vector mesons. The inverse lattice spacing $ a^{-1} $ is determined with the experimental input of $ f_pi $, while the strange quark bare mass $ m_s a = 0.08 $, and the charm quark bare mass $ m_c a = 0.80 $ are fixed such that the masses of the corresponding vector mesons are in good agreement with $ phi(1020) $ and $ J/psi(3097) $ respectively. Our results of pseudoscalar-meson decay constants are $ f_K = 152(6)(10) $ MeV, $ f_D = 235(8)(14)$ MeV, and $ f_{D_s} = 266(10)(18) $ MeV.
The masses and decay constants of pseudoscalar mesons $ D $, $ D_s $, and $ K $ are determined in quenched lattice QCD with exact chiral symmetry. For 100 gauge configurations generated with single-plaquette action at $ beta = 6.1 $ on the $ 20^3 tim
Finite energy QCD sum rules with Legendre polynomial integration kernels are used to determine the heavy meson decay constant $f_{B_c}$, and revisit $f_B$ and $f_{B_s}$. Results exhibit excellent stability in a wide range of values of the integration
Using a $3.19~mathrm{fb}^{-1}$ data sample collected at an $e^+e^-$ center-of-mass energy of $E_{rm cm}=4.178$ GeV with the BESIII detector, we measure the branching fraction of the leptonic decay $D_s^+tomu^+ u_mu$ to be $mathcal{B}_{D_s^+tomu^+ u_m
A calculation of the ratio of leptonic decay constants f_{K^+}/f_{pi^+} makes possible a precise determination of the ratio of CKM matrix elements |V_{us}|/|V_{ud}| in the Standard Model, and places a stringent constraint on the scale of new physics
We report results of our recent works [1,2] where we where the correlations between the c,b-quark running masses{m}_{c,b}, the gluon condensate<alpha_s G^2> and the QCD coupling alpha_s in the MS-scheme from an analysis of the charmonium and bottomiu