Hadronic matrix elements of gluon operators in the instanton vacuum

dc.creatorDiakonov, D. I.
dc.creatorPolyakov, M. V.
dc.creatorWeiss, C.
dc.date1995-10-05
dc.date1996-02-06
dc.date.accessioned2026-07-07T10:58:12Z
dc.date.available2026-07-07T10:58:12Z
dc.descriptionWe propose a method to evaluate hadronic matrix elements of QCD gluon operators in the instanton vacuum. We construct the ground state of the interacting instanton ensemble for non-zero $\vartheta$--angle using a variational principle. A method to study the $\vartheta$--dependence of observables on the lattice is suggested. We then derive the effective fermion action, which allows to calculate hadronic correlation functions in a $1/N_c$--expansion (Nambu--Jona-Lasinio type effective fermion theory). Gluon operators are systematically represented as effective fermion operators. Physical matrix elements are obtained after integrating the correlation functions over fluctuations of the numbers of instantons. The influence of the fermion determinant on the topological susceptibility is taken into account. Our effective description gives matrix elements fully consistent with the trace and $U(1)_A$ anomalies. The approach allows to consistently evaluate the nucleon matrix elements of various gluon and mixed quark--gluon operators in a chiral soliton picture of the nucleon.
dc.description40 pp. The discussion of the value of g_A^0 and of ref.[36] has been updated. A trivial error in formulas of section 5 has been corrected. This is the final version to appear in Nucl. Phys. B
dc.identifierhttps://arxiv.org/abs/hep-ph/9510232
dc.identifierhttp://arxiv.org/abs/hep-ph/9510232
dc.identifierNucl.Phys.B461:539-580,1996
dc.identifierdoi:10.1016/0550-3213(95)00675-3
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/187016
dc.subjectHigh Energy Physics - Phenomenology
dc.subjectHigh Energy Physics - Lattice
dc.titleHadronic matrix elements of gluon operators in the instanton vacuum
dc.typetext

Files

Collections