A Study Of SU(3) Baryons In Covariant Chiral Effective Theory

Although quantum chromodynamics(QCD)is generally accepted as the fundamental theory for describing strong interactions,quark confinement makes it difficult to use the theory for analytical calculation in the low and medium energy regions directly.For this reason,people have developed Lattice QCD for non-perturbation calculation.At present,the quark mass larger than the physical value is needed in the numerical calculation,and the results need to be further extrapolated to the region of the physical value.Therefore,the self-consistent analytic results is still needed.This made the chiral perturbation theory which is a low-energy efficient field theory of QCD get well-known and achieve great success in the study of meson systems.However,due to the scale of the baryon mass is very large,when this theory was applied to the baryon system,it broke the chiral power counting rules.For this reason,many methods have been tried to restore the chiral power counting rules,such as the expansion of heavy baryons,but it was found that the expansion cannot give convergence results in some cases.Since then,multiple attempts have been made by introducing a lot of complex regularization under the covariant framework to guarantee the chiral power counting rules.Several years ago,under the covariant form,our team found the terms that break the rules are all localized and can be directly subtracted without introducing extra operations.In this paper,under the frame of covariant chiral efficiency theory,we first calculated some one-loop diagrams describing the structure of single nucleon and nucleon-nucleon scattering,which proves that our scheme is completely feasible.We call it extended minimal subtraction scheme,or (?) for short.Compared with other methods,this scheme is more concise,and no need to introduce extra operations,it can not only maintains the analytic property of loop diagrams,but also will not lead to excessive subtraction.In the SU(3)system,we calculated the one-loop diagrams correction to the axial vector and mass of octet baryons by the virtual octet baryons,and found that the scheme is still applicable.In particular,when we considered the contribution of decuplet baryons to the octet baryon masses,some "abnormal" results appeared,but when we further expanded these "abnormal" terms,we found that they still belong to the relativistic correction.At same time,when we discussed the correction of the octet baryon mass,we also carried out further numerical analysis of the results.It is found that the chiral contribution is dominant,which is consistent with the results of other literatures.However,in addition to the chiral contribution,our calculations also retain relativistic correction terms,which are meaningful to revise baryon masses accurately.