THE PION-NUCLEON COUPLING CONSTANT IN QCD SUM RULES

摘要

The pion-nucleon coupling constant g(pi N) is studied on the basis of the QCD sum rules. Both the Borel sum rules and the finite energy sum rules for g(pi N) are used to examine the effects of higher dimensional operators (up to dimension 7) and alpha(s) corrections in the operator product expansion. Agreement with the experimental number is reached only when S-pi/S-N is greater than one, where S-pi (S-N) is the continuum threshold for the g(pi N) (nucleon) sum rule. [References: 21]