Semileptonic decays Λb→Λcl(V)over-barl in light-front dynamics

The semileptonic decays Lambda(b) ---> Lambda(c)l (v) over bar(l) are analyzed within light-front dynamics. The covariant approach to light-front dynamics is used to determine transition form factors on the basis of the matrix elements of the vector and axial-vector currents. The wave functions of heavy baryons are found as solutions to a relativistic two-particle equation in the quark-diquark model. It is found that the transition form factors obtained in this way decrease much more slowly than those deduced in the studies employing model wave functions constructed under the assumption that they factorize in x and k(perpendicular to). As a result, the value obtained in our study for the total width with respect to the decay Lambda(b) --> Lambda(c)l<(nu)over bar>(l) is approximately twice as great as those in the models relying on the factorization ansatz.