Baryon Spectral-Function Sum Rules

Sum rules for charmed baryon masses.

The measured masses of the three charge states of the charmed Σc baryon are found to be in disagreement with a sum rule based on the quark model, but relying on no detailed assumptions about the form of the interaction. This poses a significant problem for the charmed baryon sector of the quark model. Other relations among charmed baryon masses are also discussed. PACS numbers: 12.40.Yx., 14.20...

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

Determination of pion-baryon coupling constants from QCD sum rules.

We evaluate the πNN , πΣΣ and πΣΛ coupling constants using QCD sum rules based on pion-to-vacuum matrix elements of correlators of two interpolating baryon fields. The parts of the correlators with Dirac structure k/γ5 are used, keeping all terms up to dimension 5 in the OPE and including continuum contributions on the phenomenological side. The ratios of these sum rules to baryon mass sum rule...

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) ...