Semileptonic Λ b decay to excited Λ c baryons at order Λ QCD
نویسندگان
چکیده
Exclusive semileptonic Λb decays to excited charmed Λc baryons are investigated at order ΛQCD/mQ in the heavy quark effective theory. The differential decay rates are analyzed for the Jπ = 1/2− Λc(2593) and the J π = 3/2− Λc(2625). They receive 1/mc,b corrections at zero recoil that are determined by mass splittings and the leading order Isgur-Wise function. With some assumptions, we find that the branching fraction for Λb decays to these states is 2.5–3.3%. The decay rate to the helicity ±3/2 states, which vanishes for mQ → ∞, remains small at order ΛQCD/mQ since 1/mc corrections do not contribute. Matrix elements of weak currents between a Λb and other excited Λc states are analyzed at zero-recoil to order ΛQCD/mQ. Applications to baryonic heavy quark sum-rules are explored.
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تاریخ انتشار 1998