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The Investigations Of Properties Of Single ?_c~+ Hypernuclei And Symmetry Energy Effect Within Quark Mean-field Model

Posted on:2021-03-30Degree:MasterType:Thesis
Country:ChinaCandidate:L Z WuFull Text:PDF
GTID:2370330611494907Subject:Theoretical Physics
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The quark mean-field?QMF?model is applied to study the properties of s-ingle?c+hypernuclei and the effect of symmetry energy on properties of nuclear many-body system.In QMF model,the baryon is composed of three constituent quarks,which are confined by central harmonic oscillator potentials.The strong interaction between baryons is described via meson exchange between quarks.Furthermore the effects of?pion and gluon corrections on baryon mass are con-sidered.We firstly study the ground-state properties of single?c+hypernuclei,within the degree of freedom of charm quark.In QMF model,the?c+hyperon is constituted by three constituent quarks,u,d,c.The strengthes of confinement potential for u and d quarks are determined by fitting the nucleon mass and radius in free space,and those for c quark are determined by fitting the experimental masses of free charmed baryons,?c+,?c+,and?cc++.The properties of single?c+hypernuclei are generated by the?c+N potential,which depends on the coupling strength between?meson and?c+hyperon,g??c+,in the QMF model,since the scalar components of?c+N already are obtained from quark level.In the present work,two different schemes are adopted to determine g??c+because of the lack of relevant experimental data about?c+N potential.When the naive quark counting rules are adopted,i.e.,g??c+=2/3g?N,the massive single?c+hypernuclei can be bond,whose binding energy decreases with mass number increasing due to the repulsive contribution of coulomb interaction between?c+hyperons and protons.When the result from latest lattice?c+N potential is applied to determine g??c+,there are only up to A<50 for single?c+hypernuclei existing.In addition,the cross coupling term of?meson and?meson is introduced in the QMF model,by fitting the isoscalar ground-state properties of double magic nuclei and adjusting isovector coupling parameters about quark,hadron and meson.The parameters with different symmetry energy slope are obtained in order to investigate the ef-fect of symmetry energy on properties of nuclear many-body system.It is found that there is a strong correlation between the slope of symmetry energy and the neutron skin thickness of neutron-rich nuclei.The large symmetry energy slope can depress the neutron density distribution of nuclei.The binding energy of pure neutron nuclear matter is significantly affected by the symmetry energy s-lope.Furthermore,the maximum mass and corresponding radius of neutron star are less influenced by the symmetry energy slope,while the radius of medium mass neutron star are strongly dependent on the symmetry enenrgy slope.There is strongly linear correlation between the radius of 1.4M?neutron star and the symmetry energy slope,R1.4=11.80+0.02134L.In addition,a power correla-tion between tidal deformability and radius of 1.4M?neutron star is found as,?1.4=9.21×10-3×R1.44.38.
Keywords/Search Tags:quark mean field model, single ?_c~+ hypernuclei, the effect of symmetry energy, neutron stars
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