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Width difference in the $B_s$-$\bar{B}_s$ system with lattice NRQCD

S. Hashimoto·K-I. Ishikawa·T. Onogi·N. Yamada
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Abstract

We compute the matrix element of the four-quark operator $\Op_S$ = $\bar{b}(1-γ_5) s \bar{b} (1-γ_5) s$ in the $B_s-\bar{B}_s$ mixing on the lattice using NRQCD, which gives a leading contribution in the calculation of the width difference $ΔΓ_s$ in the $1/m_b$ expansion. Using the next-to-leading formula of Beneke \textit{et al.}, we obtain $(ΔΓ/Γ)_s$ = 0.151(37)(36)(17), where the the first error reflects the uncertainty of $f_{B_s}$ = 245(30) MeV, the second error comes from our calculation of the matrix element of $\Op_S$, and the third represents unknown $1/m_b$ correction.

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S. Hashimoto, K-I. Ishikawa, T. Onogi, N. Yamada. 2000-04-22. Width difference in the $B_s$-$\bar{B}_s$ system with lattice NRQCD. https://doi.org/10.1103/physrevd.62.034504

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