Semi-leptonic Octet Baryon Weak Axial-Vector Form Factors in the Chiral Constituent Quark Model

Abstract

The weak vector and axial-vector form factors have been investigated for the semi-leptonic octet baryon decays in the chiral constituent quark model with configuration mixing (χCQM config ). The effects of SU(3) symmetry breaking and configuration mixing have also been investigated and the results are not only in good agreement with existing experimental data but also show improvement over other phenomenological models.

SU(3) breaking in hyperon transition vector form factors

“…At the relevant values of q 2 max = (M B1 − M B2 ) 2 , indicated by the green vertical band on the figure, it is clear that |f 3 /f 1 | < {0.15, 0.2} (where the two numbers are for the Ξ → Σ and Σ → N transitions respectively) is a conservative bound. This is supported by both quenched lattice simulations [18,19] and quark models [37] which find small values for that ratio over a range of values of q 2 . Taking these bounds, scaled by the appropriate kinematic factors, the contri-bution from f 3 to f 0 is then for each set of simulation pseudoscalar masses negligible compared with the statistical uncertainties of the calculation.…”

Electromagnetic form factors of octet baryons with the nonlocal chiral effective theory

“…Theoretically, though QCD is the fundamental theory to describe strong interactions, it is difficult to study hadron physics using QCD directly. There are many phenomenological models, such as the cloudy bag model [5], the constituent quark model [6], the 1/Nc expansion approach [7], the Nambu-Jona-Lasino (NJL) model [8], the perturbative chiral quark model (PCQM) [9], the extended vector meson dominance model [10], the SU(3) chiral quark model [11], the quark-diquark model [12], and so on. These model calculations are helpful to provide the physical scenario for the hadron structure.…”

Sea quark contributions to nucleon electromagnetic form factors with the nonlocal chiral effective Lagrangian *

“…Though QCD is the fundamental theory to describe strong interactions, it is difficult to study hadron physics using QCD directly. There are many phenomenological models, such as the cloudy bag model [8], the constituent quark model [9], the 1/Nc expansion approach [10], the perturbative chiral quark model [11], the extended vector meson dominance model [12], the SU(3) chiral quark model [13], the quark-diquark model [14], etc. Besides the above phenomenological models, heavy baryon and relativistic chiral perturbation theory have been widely applied to study the hadron spectrum and structure.…”