Next - to - leading order Q 2 - evolution of the transversity distribution h 1 ( x , Q 2 )

We present a calculation of the two-loop anomalous dimension for the transversity distribution h1(x,Q ), γ n , in the MS scheme of the dimensional regularization. Due to the chiral-odd nature, h1 does not mix with the gluon distributions, and thus our result is the same for the flavor-singlet and nonsinglet distributions. At small n (moment of h1), γ h(1) n is significantly larger than γ n (the anomalous dimension for the nonsinglet f1), but approaches γ n very quickly at large n, keeping the relation γ h(1) n > γ f(1) n . This feature is in parallel to the relation between the one-loop anomalous dimension for f1 and h1. PACS numbers: 13.85.Qk, 12.38.Bx, 13.88.+e, 14.20.Dh