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تسجيل مستخدم جديدPseudoscalar Mass and Decay Constant in Lattice QCD with Exact Chiral Symmetry
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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 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 constant are: $ f_K = 152(6)(10) $ MeV, $ f_D = 235(8)(14)$ MeV, and $ f_{D_s} = 266(10)(18) $ MeV [hep-ph/0506266]. The latest experimental result of $ f_{D^+} $ from CLEO [hep-ex/0508057] is in good agreement with our prediction.
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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.
We present the results of a lattice QCD calculation of the pseudoscalar meson decay constants f_K, f_D and f_Ds, performed with N_f=2 dynamical fermions. The simulation is carried out with the tree-level improved Symanzik gauge action and with the tw
isted mass fermionic action at maximal twist. With respect to our previous study (0709.4574 [hep-lat]), here we have analysed data at three values of the lattice spacing (a=0.10 fm, 0.09 fm, 0.07 fm) and performed the continuum limit, and we have included at a=0.09 fm data with a lighter quark mass (m_pi = 260 MeV) and a larger volume (L = 2.7 fm), thus having at each lattice spacing L >= 2.4 fm and m_pi*L >= 3.6. Our result for the kaon decay constant is f_K=(157.5 +- 0.8|_{stat.} +- 3.3|_{syst.}) MeV and for the ratio f_K/f_pi=1.205 +- 0.006|_{stat.} +- 0.025|_{syst.}, in good agreement with the other N_f=2 and N_f=2+1 lattice calculations. For the D and D_s meson decay constants we obtain f_D=(205 +- 7|_{stat.} +- 7|_{syst.}) MeV, in good agreement with the CLEO-c experimental measurement and with other recent N_f=2 and N_f=2+1 lattice calculations, and f_{Ds}=(248 +- 3|_{stat.} +- 8|_{syst.}) MeV that, instead, is 2.3 sigma below the CLEO-c/BABAR experimental average, confirming the present tension between lattice calculations and experimental measurements.
We calculate the form factors of the $K to pi l u$ semileptonic decays in three-flavor lattice QCD, and study their chiral behavior as a function of the momentum transfer and the Nambu-Goldstone boson masses. Chiral symmetry is exactly preserved by
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