arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2004.01706hep-phnucl-th
收藏

作为自发破缺半经典$SU(2)_L \times SU(2)_R$手征微扰理论液相的核物质：静态手征核子液体

Nuclear matter as a liquid phase of spontaneously broken semi-classical $SU(2)_L \times SU(2)_R$ chiral perturbation theory: Static chiral nucleon liquids

Bryan W. Lynn, Brian J. Coffey, Kellen E. McGee, Glenn D. Starkman

备注：
68 pages, 4 figures, subbmitted to Phys. Rev. C. arXiv admin note: substantial text overlap with arXiv:1811.10784
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

本文研究了基于双无质量夸克QCD手征对称性整体自发破缺的核结构有效场论。对于基态核，EFT使扩展和截断的$Λ_{χSB}\simeq 1 GeV$的逆功率，与分析运营商重整化的所有循环订单。我们推导出了$Λ^0_{χSB}$阶的EFT拉格朗日量。我们发现，质子，中子和π介子的$SU(2)χPT$承认一个半经典的“静态手征核子液体”（静态$χ$ NL）相，并在这种液体中出现“无π介子”$SU(2)χPT$：远红外π介子从静态$χ$ NL去耦，大大简化了饱和核物质（无限液相）和有限微观液滴（基态核素）的推导。静态$χ$ NL完全由偶宇称、总自旋为零、偶$Z$和$N$的核子组成;自旋和动量的局部期望值为零。他们解释了无π介子的$SU(2)χPT$捕获某些核素实验基态性质的能力，这种解释直接来自于具有两个无质量夸克的QCD的整体对称性。平均场静态$χ$ NL非拓扑孤子是$SU(2)χPT$半经典对称性的真解：它们服从所有的CVC和PCAC守恒律，并且它们具有零内压和零外压。核液滴模型和半经验质量公式出现-正确的核密度和饱和和不对称的能量-在一个明确的C-Fermi结构。我们将我们的工作与无介子和晕/团簇EFT中的兼容和互补工作相关联，EFT也完全由核子组成并应用于轻（$A\leq 6$）核，这可能对静态$χNL$提供重要（<12.5%）的校正。

英文摘要：

We study effective field theories (EFT) of nuclear structure based on spontaneously broken global $SU(2)_L\times SU(2)_R$ chiral symmetry of QCD with two massless quarks, i.e. $SU(2)χPT$. For ground-state nuclei, this EFT enables expansion and truncation in inverse powers of $Λ_{χSB}\simeq 1 GeV$, with analytic operators renormalized to all loop orders. We derive the EFT Lagrangian to order $Λ^0_{χSB}$. We show that $SU(2)χPT$ of protons, neutrons and pions admits a semi-classical "Static Chiral Nucleon Liquid" (Static$χ$NL) phase and that "Pion-less" $SU(2)χPT$ emerges in this liquid: far-infrared pions decouple from Static$χ$NL, vastly simplifying the derivation of saturated nuclear matter (the infinite liquid phase) and of finite microscopic liquid drops (ground-state nuclides). Static$χ$NL are made entirely of nucleons with even parity, total spin zero, and even $Z$ and $N$; local expectation values for spin and momenta vanish. They explain the power of pion-less $SU(2)χPT$ to capture experimental ground-state properties of certain nuclides, this explanation following directly from the global symmetries of QCD with two massless quarks. Mean-field Static$χ$NL non-topological solitons are true solutions of $SU(2)χPT$'s semi-classical symmetries: they obey all CVC and PCAC conservation laws and they have zero internal and external pressure. The nuclear liquid-drop model and the semi-empirical mass formula emerge -- with correct nuclear density and saturation and asymmetry energies -- in an explicit Thomas-Fermi construction. We relate our work to compatible and complementary work in pionless and in halo/ cluster EFTs, also composed entirely of nucleons and applied to light ($A\leq 6$) nuclei, which might provide important (<12.5%) corrections to Static$χNL$.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑