Chiral Baryon Fields in the QCD Sum Rule

We study the structure of local baryon fields using the method of QCD sum rule. We only consider the single baryon fields and calculate their operator product expansions. We find that the octet baryon fields belonging to the chiral representations [(3,3*)+(3*,3)] and [(8,1)+(1,8)] and the decuplet baryon fields belonging to the chiral representations [(3,6)+(6,3)] lead to the baryon masses which are consistent with the experimental data of ground baryon masses. We also calculate their decay constants, check our normalizations for baryon fields in PRD81:054002(2010) and find that they are well-defined.Comment: 12 pages, 6 figure, 1 table, accepted by EPJ

Nucleon axial coupling constants and QCD sum rules

QCD sum rules are used to obtain the isovector and isoscalar'' axial vector coupling constants, g{sub A} and g{sub A}{sup S}. We find g{sub A} = 1.26 {plus minus} 0.08, g{sub A}{sup S} = 0.13 {plus minus} 0.08 with sum results for g{sub A}{minus}1 and g{sub A} + g{sub A}{sup S}. These sum rules also show that in the limit of chiral symmetry restoration, g{sub A} {yields} 1 and g{sub A}{sup S} {yields} {minus}1

Weak quasielastic electroproduction of hyperons with polarization observables

With the availability of high luminosity electron beam at the accelerators, there is now the possibility of studying weak quasielastic hyperon production off the proton, i.e. $e^-p \to \nu_e Y(Y=\Lambda,\Sigma^0)$, which will enable the determination of the nucleon-hyperon vector and axial-vector transition form factors at high $Q^2$ in the strangeness sector and provide test of the Cabibbo model, G-invariance, CVC, PCAC hypotheses and SU(3) symmetry. In this work, we have studied the total cross section, differential cross section as well as the longitudinal and perpendicular components of polarization of the final hyperons ($\Lambda$ and $\Sigma^0$ produced in these reactions) and presented numerical results for these observables and their sensitivity to the transition form factors.Comment: 14 pages, 10 figures, 2 table