Relativistic Mean-field Approach For ?,?,and ? Hypernuclei

Since the first?hypernucleus was discovered,the study of hypernuclei has attracted worldwide interest in both experimental observations and theoretical calculations,which has become an important branch of research in nuclear physics.The relativistic mean field model is one of the most successful microscopic methods,not only achieved great success in describing the structural properties of ordinary nuclei in the middle and heavy regions,but also been used to describe the structural properties of hypernuclei.In this paper,we will systematically study the properties of single-?,?,and?hypernuclei within the contain strangeness degree of freedom relativistic mean field theory.The YN coupling constants are properly constrained.This paper is mainly divided into the following three parts:?1?By adding a hyperon to ⁴⁰Ca,the mean-field potentials,single-particle levels and density distributions for hyperons(?,?^0,-,and?^+,0,-)are compared and the impurity effects on the nuclear core are examined.In general,the?and?⁰ hyperons show similar behaviors in bulk properties since both of them are electroneutral and have similar coupling constants;However,?⁰ hyperon owns the shallowest mean-field potential well with the most extended density distribution.The Coulomb interactions play vital roles in the charged?⁺,?^-,and?^-hyperons.As a result,those hyperons have different impurity effects on the nuclear core ⁴⁰Ca.For example,?⁰and?⁺hyperons decrease R_n,?^-and?^-hyperons increase R_n,?and?⁰ hyperons have almost no influences on R_n.?2?Taking ⁴⁰Ca+Y(Y=???^+,0,-and?^0,-)as example,the?YY tensor couplings and the effects on the single-hyperon levels are studied.In general,the?YY tensor couplings obviously influence the spin-orbit splittings but have different effects for different hyperons.In particular,for the?^0,-hyperons,the level ordering is inverted by large?YY tensor potential.?3?Taking ¹⁶O+Y?⁴⁰Ca+Y?⁹⁰Zr+Y?²⁰⁸Pb+Y as example,the mass dependence of the single-hyperon binding energies are discussed.In generally,The binding energy of the hypernuclei is proportional to the change of the mass number,but there are significant differences in numerical values for different hyperons.In addition,for the?⁺hyperon,its single-hyperon the evolution trend of the binding energy is not monotonous,where is a turning point athypernuclei.It is mainly caused by the repulsive Coulomb interaction.