L=1 Mesons and the Four-Quark Condensate in QCD Sum Rules

摘要

We systematically study the L=1 meson spectrum in the context of QCD sum rules for bilinear quark currents of dimension three. We improve the sum rules by including the alpha /sub s/ corrections correctly and take into account the running of the coupling constant. A correct prediction for the B(1/sup +-/) meson can be obtained provided there is a sizeable departure of the value of the four-quark condensate <0vertical strokeanti qlambda/sup a/qanti qlambda/sup a/qvertical stroke0> from its factorized value using the vacuum dominance assumption. For the condensates <0vertical strokeanti q gamma /sub mu /lambda/sup a/qanti q gamma /sub mu /lambda/sup a/qvertical stroke0> and <0vertical strokeanti qsigma/sub mu nu /lambda/sup a/qanti qsigma/sub mu nu /lambda/sup a/qvertical stroke0> no such deviation is observed. (ERA citation 12:023849)