Euler-Mahonian polynomials for C_a wr S_n

In a recent paper, Regev and Roichman introduced the <_L order and the L-descent number statistic, des_L, on the group of colored permutations, C_a \wr S_n. Here we define the L-reverse major index statistic, rmaj_L, on the same group and study the distribution of des_L and the bi-statistic (des_L, rmaj_L). We obtain new wreath-product analogues of the Eulerian and q-Euler-Mahonian polynomials, and a generalization of Carlitz's identity.