出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We discuss the heavy-quark effective theory (HQET) parameters, lE and lH, which correspond to matrix elements representing quark-gluon three-body components in the B-meson wavefunction. We derive the QCD sum rules for lE;H calculating the new higher-order contributions to the operator product expansion for the relevant correlator in the HQET, i.e., the order as radiative corrections to the Wilson coefficients associated with the dimension-5 quark-gluon mixed operator, and the power corrections due to the dimension-6 four-quark operators. We find that the new radiative corrections significantly improve the stability of the corresponding Borel sum rules and lead to the reduction of the values of lE;H. We also discuss the improvement for the sum rules with the resummation of the relevant logarithms of the b-quark mass based on the renormalization group and present update on the values of lE;H.
