Baryon QCD sum rules in an external isovector-scalar field and baryon isospin mass splittings

Baryon QCD sum rules in an external isovector-scalar field and baryon isospin mass splittings.

Within the QCD sum-rule approach in an external field, we calculate the baryon matrix element of isovector-scalar current, HB = 〈B|uu−dd|B〉/2MB, for octet baryons, which appears in the response of the correlator of baryon interpolating fields to a constant isovector-scalar external field. The sum rules are obtained for a general baryon interpolating field with an appropriate form for the phenom...

Scalar-Meson-Baryon Coupling Constants in QCD Sum Rules

The external-field QCD Sum Rules method is used to evaluate the coupling constants of the light-isoscalar scalar meson (“σ” or ǫ) to the Λ, Σ, and Ξ baryons. It is shown that these coupling constants as calculated from QCD Sum Rules are consistent with SU(3)-flavor relations, which leads to a determination of the F/(F + D) ratio of the scalar octet assuming ideal mixing: we find αs ≡ F/(F + D) ...

Baryon Hyperfine Mass Splittings in Large N QCD

The hyperfine mass splittings of baryons in largeN QCD are proved to be proportional to J. Hyperfine mass splittings are first allowed at order 1/N in the 1/N expansion. UCSD/PTH 93-19 hep-ph/9307244 July 1993

Chirality and Reliability of Baryon QCD Sum Rules

The QCD sum-rule method has been widely used in studying various baryon properties. For a given problem, there are usually more than one sum rules and they do not work equally well. In this paper, we point out that chirality plays an important role in determining the reliability of a baryon sum rule. The contributions of positiveand negative-parity excited baryon states partially cancel each ot...

Vector-meson-baryon coupling constants in QCD sum rules