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تسجيل مستخدم جديدHQE parameters from unquenched lattice data on pseudoscalar and vector heavy-light meson masses
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We present a new lattice determination of some of the parameters appearing both in the Operator Product Expansion (OPE) analysis of the inclusive semileptonic $B$-meson decays and in the Heavy Quark Expansion (HQE) of the pseudoscalar (PS) and vector (V) heavy-light meson masses. We perform a lattice QCD (LQCD) computation of PS and V heavy-light meson masses for heavy-quark masses $m_h$ in the range from $m_c^{rm phys}$ to $simeq 4m_b^{rm phys}$. We employed the $N_f = 2+1+1$ gauge configurations of the European Twisted Mass Collaboration (ETMC) at three values of the lattice spacing $a simeq (0.062, 0.082, 0.089)$ fm with pion masses in the range $M_pi simeq (210 - 450)$ MeV. The heavy-quark mass is simulated directly on the lattice up to $simeq 3m_c^{rm phys}$. The interpolation to the physical $m_b^{rm phys}$ is performed using the ETMC ratio method and adopting the kinetic mass scheme. We obtain $m_b^{rm kin}(1~mbox{GeV}) = 4.61 (20)$ GeV ($overline{m}_b(overline{m}_b) = 4.26 (18)$ GeV in the $overline{rm MS}$ scheme). The lattice data are analyzed in terms of the HQE and the matrix elements of dimension-4 and dimension-5 operators are extracted with good precision, namely: $overline{Lambda} = 0.552 (26)$ GeV, $mu_pi^2 = 0.321 (32)$ GeV$^2$ and $mu_G^2(m_b) = 0.253 (25)$ GeV$^2$. The data also allow for an estimate of the dimension-6 operator matrix elements.
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