SemileptonicBdecays to excited charmed mesons

Abstract

Exclusive semileptonic B decays into excited charmed mesons are investigated at order ⌳ QCD /m Q in the heavy quark effective theory. Differential decay rates for each helicity state of the four lightest excited D mesons ͑D 1 , D 2 * , D 0 * , and D 1 *͒ are examined. At zero recoil, ⌳ QCD /m Q corrections to the matrix elements of the weak currents can be written in terms of the leading Isgur-Wise functions for the corresponding transition and meson mass splittings. A model independent prediction is found for the slope parameter of the decay rate into helicity zero D 1 at zero recoil. The differential decay rates are predicted, including ⌳ QCD /m Q corrections with some model dependence away from zero recoil and including order ␣ s corrections. Ratios of various exclusive branching ratios are computed. Matrix elements of the weak currents between B mesons and other excited charmed mesons are discussed at zero recoil to order ⌳ QCD /m Q . These amplitudes vanish at leading order, and can be written at order ⌳ QCD /m Q in terms of local matrix elements. Applications to B decay sum rules and factorization are presented. ͓S0556-2821͑98͒02901-4͔

B physics at the Z0resonance

“…The decay rates and form factors predicted by the calculation of Leibovich et al [30] have been used, with the free parameters of the calculation constrained by experimental measurements of the ratio R * * = Γ(B → D * 2 ℓν)/Γ(B → D 1 ℓν) = 0.37 ± 0.16 [7]. A recent preliminary DELPHI analysis [31] has searched for mass structure in B → D * + π − ℓν,B → D 0 π + ℓν andB → D + π − ℓν decays, by combining charged pions with exclusively reconstructed D ( * ) ℓ combinations.…”

Bounds on the derivatives of the Isgur–Wise function from sum rules in the heavy quark limit of QCD

“…Therefore, the functions τ (1) 1/2 (w) and τ (1) 3/2 (w) correspond, respectively, to the functions ζ(w) and τ (w) defined by Leibovich et al [4]. But in all this paper we will keep the general notation τ (ℓ)(n) ℓ+1/2 (w), τ (ℓ)(n) ℓ−1/2 (w).…”

Sum rules in the heavy quark limit of QCD

“…Since the formulation of Bjorken sum rule [1], other sum rules (SR) have been derived involving leading and subleading quantities in the heavy quark expansion [2,3,4,5]. The recent Uraltsev SR [5] at leading order came as a big surprise, leading to the rigorous lower bound for the elastic Isgur-Wise function ρ 2 ≥ 3/4 2 .…”