SemileptonicBdecays to excited charmed mesons
Citations Over TimeTop 10% of 1998 papers
Abstract
Exclusive semileptonic $B$ decays into excited charmed mesons are investigated at order ${\ensuremath{\Lambda}}_{\mathrm{QCD}}{/m}_{Q}$ 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, ${\ensuremath{\Lambda}}_{\mathrm{QCD}}{/m}_{Q}$ 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 ${\ensuremath{\Lambda}}_{\mathrm{QCD}}{/m}_{Q}$ corrections with some model dependence away from zero recoil and including order ${\ensuremath{\alpha}}_{s}$ 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 ${\ensuremath{\Lambda}}_{\mathrm{QCD}}{/m}_{Q}.$ These amplitudes vanish at leading order, and can be written at order ${\ensuremath{\Lambda}}_{\mathrm{QCD}}{/m}_{Q}$ in terms of local matrix elements. Applications to $B$ decay sum rules and factorization are presented.