Structure Of Single ? Hypernuclei Based On The Relativistic Hartree-fock Theory

Hypernuclei,the nuclear many body systems that contains strangeness-bared baryons?hyper-ons?,provide useful information on the baryon-baryon interactions.Study of hypernuclear physics becomes one of the important international frontier of nuclear physics.With the upgrading and development of radioactive-ion-beam devices,substantial information of hypernuclei has been ac-cumulated especially for single?hypernuclei,including binding energies,separation energies and spin-orbit splitting of hyperon.The theoretical study of these results reveals the complex nature of nuclear forces in medium containing strangeness degrees of freedom.Based on the successful description of nuclear matter and the properties of finite nuclei within the relativistic Hartree-Fock?RHF?theory,RHF theory is then extended to include hyperon-nucleon effective interactions,while the structure of single?hypernuclei is investigated in detail.In this thesis,theoretical formula of?hypernuclei and?hypernuclei are derived with spherical symmetry,and the structure of ground state of single?Hypernuclei is studied.Compared with the relativistic mean field?RMF?theory,the RHF theory includes extra effects from Fock terms.The?N effective interaction is first determined by fitting to the experimental data of binding energies of single?hypernuclei.Then the equilibrium of nuclear dynamics for single?hypernuclei are studied,revealing the effects from Fock terms.It is found that the balance of hypernuclear ground state is mainly dominated by the potential energy of the isospin scalar coupling channel.In fact,for Hartree terms of nucleon channels,the results of PKO-series functionals in RHF give stronger attraction than that of the RMF parameter set PKDD,while the repulsive contribution provided by the Fock terms maintains the equilibrium of nuclear dynamics of the nucleon part.However,because only one hyperon is emerged in a single?hypernuclei,the additional repulsion provided by the Fock term in the energy functional of the hyperon channel is not sufficient to compensate the enhanced attractive contribution from the Hartree term.Then the coupling constant g_??of the hyperon-nucleon effective interaction in RHF must be reduced,compared with RMF,in order to obtain better equilibrium of nuclear dynamics.Furthermore,the Fock-terms related effects of hyperon spin-orbit splittings has been studied.The spin-orbit splittings within RHF functionals are found to be significantly smaller than the RMF ones,originating from smaller spin-orbit coupling potentials given by RHF.Then the evolution of spin-orbit splitting and mean field are studied by changing the hyperon coupling constant.The val-ues of splitting become smaller when the hyperon coupling constant decreases,approaching closer to the empirical value.By analyzing the evolution of selected isotopic chain of hypernuclei,it is found that the features of nucleon shell structure plays an important role,more remarkable in RMF,in both the radius of hypernucleus and the spin-orbit splitting of?hyperon.The conclusions from this thesis are expected to provide essential knowledge theoretically which is related to upcoming hypernuclear experiments,and could provide a more reliable and self-consistent theoretical model to better illustrate the hyperon-nucleon and hyperon-hyperon interactions.