ZhETF, Vol. 148,
p. 470 (September 2015)
(English translation - JETP,
Vol. 121, No. 3,
available online at www.springer.com
NUCLEON QCD SUM RULES IN THE INSTANTON MEDIUM
Ryskin M.G., Drukarev E.G., Sadovnikova V.A.
Received: April 3, 2015
We try to find grounds for the standard nucleon QCD sum rules, based on a more detailed description of the QCD vacuum. We calculate the polarization operator of the nucleon current in the instanton medium. The medium (QCD vacuum) is assumed to be a composition of the small-size instantons and some long-wave gluon fluctuations. We solve the corresponding QCD sum rule equations and demonstrate that there is a solution with the value of the nucleon mass close to the physical one if the fraction of the small-size instantons contribution is .