On the four-quark operator matrix elements for the lifetime of $$\Lambda _{b}$$

Abstract

AbstractHeavy quark expansion can nicely explain the lifetime of $$\Lambda _{b}$$ Λ b . However, there still exist sizable uncertainties from the four-quark operator matrix elements of $$\Lambda _{b}$$ Λ b in $$1/m_{b}^{3}$$ 1 / m b 3 corrections, which describe the spectator effects. In this work, these four-quark operator matrix elements are investigated using full QCD sum rules for the first time. At the QCD level, contributions from up to dimension-6 four-quark operators are considered. Our method for calculating high-dimensional operator matrix elements holds promise for use in resolving the $$\Omega _{c}$$ Ω c lifetime puzzle.