A novel determination of the Bc lifetime

To reduce the current theory uncertainties a novel way to determine the B(c )lifetime, tau B-c, is proposed. Taking the difference of the B-c, and B and D meson decay rates eliminates the leading contributions from the calculation, which exhibit large scale and scheme dependence. The uncertainties in the proposed determination of tau B-c are analyzed and improvements are proposed. The method predicts a value of tau B-c in tension with the experimental determination. Several explanations are considered, including underestimation of uncertainties, duality violation and new physics. We discuss quantitative evidence that our method is vitiated by duality violation in the large mass OPE used to calculate nonleptonic decay rates of B and D mesons. (C) 2022 The Authors. Published by Elsevier B.V.

Automated summary

A novel method is proposed in this paper to reduce the current theory uncertainties in determining the lifetime of B(c) meson, tau B-c. The method eliminates the leading contributions from calculations by taking the difference of B-c, B, and D meson decay rates, which are known to have significant scale and scheme dependence. The uncertainties in the proposed determination of tau B-c are analyzed, and improvements are suggested. The predicted value of tau B-c from the method is found to be in tension with experimental determination, and several explanations, including underestimation of uncertainties, duality violation, and new physics, are considered. The paper also discusses quantitative evidence suggesting that the method is affected by duality violation in the large mass operator product expansion used for calculating nonleptonic decay rates of B and D mesons.