Λ c semileptonic decays in a quark model

Hadronic form factors for semileptonic decay of the Λc are calculated in a nonrelativistic quark model. The full quark model wave functions are employed to numerically calculate the form factors to all relevant orders in (1/mc, 1/ms). The form factors obtained satisfy relationships expected from the heavy quark effective theory (HQET). The differential decay rates and branching fractions are calculated for transitions to the ground state and a number of excited states of Λ. The branching fraction of the semileptonic decay width to the total width of Λc has been calculated and compared with other theoretical estimates and experimental results. The branching fractions for Λc→Λ*l+νl→Σπl+νl and Λc→Λ*l+νl→NK¯l+νl are also calculated. Apart from decays to the ground state Λ(1115), it is found that decays through the Λ(1405) provide a significant portion of the branching fraction Λc→Xslνl. A new estimate for f=B(Λc+→Λl+νl)/B(Λc+→Xsl+νl) is obtained.