29 research outputs found
Dirac operator spectral density and low energy sum rules
The spectral density of euclidean Dirac operator is investigated in partially
quenched QCD with arbitrary quark masses. A representation of scalar and
pseudoscalar correlators in terms of the spectral density is discussed. The
spectral density, obtained from the partially quenched chiral perturbation
theory is shown to be compatible with low energy sum rules, obtained earlier.Comment: 8 pages, latex, published version; NLO QCD correction to the Dirac
operator spectral density is added to the tex
Fivebrane Lagrangian with Loop Corrections in Field-Theory Limit
Equations of motion and the lagrangian are derived explicitely for Dual D=10,
N=1 Supergravity considered as a field theory limit of a Fivebrane. It is used
the mass-shell solution of Heterotic String Bianchi Identites obtained in the
2-dimensional -model two-loop approximation and in the tree-level
Heterotic String approximation. As a result the Dual Supergravity lagrangian is
derived in the one-loop Five-Brane approximation and in the lowest
6-dimensional -model approximaton.Comment: 21 page
Chiral Condensates, Q_7 and Q_8 Matrix Elements and Large-N_c QCD
The correlation function of a current with a current is discussed
within the framework of QCD in the limit of a large number of colours .
Applications to the evaluation of chiral condensates of dimension six and
higher, as well as to the matrix elements of the and electroweak
penguin operators are discussed. A critical comparison with previous
determinations of the same parameters has also been made.Comment: Layout modified, size of first figure correcte