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Chiral corrections and lattice QCD results for fBs/fBd and (Delta ms/Delta md)

Damir Becirevic·Svjetlana Fajfer·Sasa Prelovsek·Jure Zupan
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Abstract

It has been argued recently that the inclusion of the chiral logarithms in extrapolation of the lattice data can shift the value of the hadronic parameter xi = (fBs sqrt(B_{Bs}))/(fBd sqrt(B_{Bd})), from 1.16(6) to 1.32(10) and even higher. If true, that would considerably change the theoretical estimate for the ratio of oscillation frequencies in the neutral Bs- and Bd-systems, and would affect the standard CKM unitarity triangle analysis. In this letter we show that (fBs/fBd) \approx (fK/fpi), and thus the uncertainty due to the missing chiral logs is smaller than previously thought. By combining the NLO chiral expansion with the static heavy quark limit we obtain xi = 1.22(8).

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Damir Becirevic, Svjetlana Fajfer, Sasa Prelovsek, Jure Zupan. 2003-09-14. Chiral corrections and lattice QCD results for fBs/fBd and (Delta ms/Delta md). https://doi.org/10.1016/s0370-2693(03)00653-1

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