Study of doubly heavy baryon lifetimes

A bstract We study the lifetimes and inclusive semileptonic decay widths of doubly heavy baryons within the framework of heavy quark expansion. Our analysis includes next-to-leading-order corrections to the dimension-3, -5, and -6 operators, together with the leading dimension-7 contributions, while the nonperturbative matrix elements are evaluated in a bag model with translationally improved baryon wave functions. We obtain (τ_Ξcc⁺⁺,τ_Ξcc⁺,τ_Ωcc⁺)=(2.67-0.94+0.95,0.47-0.08+0.09,1.79-0.62+0.64)× 10⁻¹³s τ Ξ cc + + τ Ξ cc + τ Ω cc + = 2.67 − 0.94 + 0.95 0.47 − 0.08 + 0.09 1.79 − 0.62 + 0.64 × 10 − 13 s and (τ_Ξbb⁰,τ_Ξbb⁻,τ_Ωbb⁻)=(0.75-0.11+0.13,0.92-0.15+0.15,0.93-0.15+0.15)× 10⁻¹²s τ Ξ bb 0 τ Ξ bb − τ Ω bb − = 0.75 − 0.11 + 0.13 0.92 − 0.15 + 0.15 0.93 − 0.15 + 0.15 × 10 − 12 s . The lifetime hierarchy patterns are found to be τ (Ξcc⁺⁺)>τ (Ωcc⁺)>τ (Ξcc⁺) τ Ξ cc + + > τ Ω cc + > τ Ξ cc +