Decay Constants of Heavy Pseudoscalar Mesons: Reconciling QCD Sum Rules and Lattice QCD

Wolfgang Lucha; Dmitri Melikhov; Silvano Simula

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arXiv · 1308.3157

Decay Constants of Heavy Pseudoscalar Mesons: Reconciling QCD Sum Rules and Lattice QCD

Wolfgang Lucha·Dmitri Melikhov·Silvano Simula

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Abstract

Exploiting recently proposed novel improvements of the techniques used for extracting from QCD sum rules pivotal hadron characteristics, including their systematic errors, we succeed to achieve a conspicuous agreement of the predictions of QCD sum rules for the decay constants $f_B$ and $f_{B_s}$ of the heavy pseudoscalar mesons $B$ and $B_s,$ which before tended to be slightly too large, with corresponding results from lattice QCD. Adopting for the crucial $b$-quark $\bar{\rm MS}$ mass the value $\bar{m}_b(\bar{m}_b)=(4.247\pm0.034)$ GeV, we get $f_B=(192.0\pm14.6)$ MeV and $f_{B_s}=(228.0\pm19.8)$ MeV; clearly, this may be also viewed as a determination of the $b$-quark mass from sufficiently precise decay constants.

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Wolfgang Lucha, Dmitri Melikhov, Silvano Simula. 2013-08-14. Decay Constants of Heavy Pseudoscalar Mesons: Reconciling QCD Sum Rules and Lattice QCD. https://arxiv.org/abs/1308.3157

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