Two-loop Anomalous Dimensions of Heavy Baryon Currents in Heavy Quark Effective Theory

Abstract

We present results on the two-loop anomalous dimensions of the heavy baryon HQET currents $J=(q^{T}C\Gamma \tau q){\Gamma }^{\prime }Q$ with arbitrary Dirac matrices $\Gamma$ and ${\Gamma }^{\prime }$. From our general result we obtain the two-loop anomalous dimensions for currents with quantum numbers of the ground state heavy baryons ${\Lambda }_Q$, ${\Sigma }_Q$ and ${\Sigma }_Q^{\ast }$. As a by-product of our calculation and as an additional check we rederive the known two-loop anomalous dimensions of mesonic scalar, pseudoscalar, vector, axial vector and tensor currents $(J=\bar{q}\Gamma q)$ in massless QCD as well as in HQET.

Comments: 21 pages, LaTeX, 2 figures are included in PostScript format