中子星对自旋相关轴矢量新相互作用的约束  

Constraints of neutron star on new interaction of spin-dependent axial-vector coupling

作　　者：高朋林 郑皓 孙光爱[2] Gao Peng-Lin;Zheng Hao;Sun Guang-Ai(School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China;Key Laboratory of Neutron Physics, Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics,Mianyang 621900, China)

机构地区：[1]北京科技大学数理学院,北京100083 [2]中国工程物理研究院核物理与化学研究所,中子物理学重点实验室,绵阳621900

出　　处：《物理学报》2019年第18期95-102,共8页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2017YFA0403703);国家自然科学基金(批准号:U1830205)资助的课题~~

摘　　要：众多粒子物理超标准模型中都预言了自旋有关的新相互作用存在.极化的核子间通过交换自旋为1的轴矢量玻色子可以产生额外的吸引力进而改变无穷大核物质状态方程性质.本文在相对论平均场模型的框架下加入额外的轴矢量玻色子后计算发现,当相互作用强度与玻色子质量之比达到gA^2/mZ′^2~O(10GeV^-2)时,低密处无穷大核物质的稳定性和对应的相变行为将发生显著的改变;而当gA^2/mZ′^2>130GeV^-2时核物质将在发生相变前率先到达零压点.对中子星而言这意味着其内核物质将在保持稳定的状态下形成表面而不会发生相变形成壳层结构,这与普遍存在于中子星天文观测中的星震现象矛盾,因此反过来对新相互作用的强度提出了额外的限制.通过与已有的地面实验结果对比,本文发现对于力程为微米到厘米间的新相互作用,中子星对其强度的约束最高可有8个量级的提升.It is predicted in many theories beyond the standard model that the new interaction relevant to spin isexistent. The exchange of an axial vector particle will result in attractive dipole-dipole interaction which can beviewed as an effective magnetic potential that looks quite different from those expected from electromagnetism.In this work, we demonstrate that, instead of the laboratory spin source, stringent constraints can be set onthese attractive spin-spin interactions from polarized nuclear matters within neutron stars which have extremelystrong magnetic fields (up to 1015 G in some cases). By considering such an exotic interaction within theframework of relativistic mean field model, we find that the stability of infinite nuclear matter can be influencedsignificantly when the ratio of coupling strength to boson mass become larger than gA^2 /mZ ′^2 (10GeV^-2).Furthermore, based on the curvature matrix approach, when gA^2/mZ′^2>130GeV^-2 , phase transition inside low-density nuclear matter will no longer take place before the pressure of nuclear matter becomes zero, whichforbids core-crust transition at the inner edge separating the liquid core from the solid crust of neutron stars.Thus bare neutron stars without any crusts are predicted. However, observations of pulsar glitches, i.e., theoccasional disruptions of the extremely regular pulsations from magnetized, rotating neutron stars, imply theexistence of crusts inside these dense objects. This in turn constrains the strength of the exotic interaction. Infact, in the case of dipole-dipole force on a length scale between m to cm, the highest value of these constraintscan be 8 orders of magnitude higher than those from existing laboratory results.

关 键 词：中子星 超标准模型 新相互作用 

分 类 号：O572.24[理学—粒子物理与原子核物理] P145.6[理学—物理]