The Λb lifetime in the light front quark model

Abstract

The enhancement of the Λb decay width relative to B decay due to the difference in Fermi motion effects in Λband B is calculated in the light front quark model with the simplifying assumption that Λbconsists of a heavy quark and a light scalar diquark. In order to explain the large deviation from unity in the experimental result for τ(Λb)/τ(B), it is necessary that the diquark be light and the ratio of the squares of the Λb and B wave functions at the origin be ≲1.