arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1707.02883nucl-thnucl-ex
收藏

手征动力学的轻核谱

Light-nuclei spectra from chiral dynamics

M. Piarulli, A. Baroni, L. Girlanda, A. Kievsky, A. Lovato, Ewing Lusk, L. E. Marcucci, Steven C. Pieper, R. Schiavilla, M. Viviani, R. B. Wiringa

摘要:

原子核理论的一个主要目标是根据原子核的组成部分--核子,即,质子和中子。这种方法,以下称为核理论的基本模型,是用点状核子来表述的,它作为有效自由度出现,在足够低的能量下,作为从基本夸克和胶子开始的抽取过程的结果,由量子色动力学(QCD)描述。手征有效场论在低能展开的框架下提供了一种系统的方法来解释QCD对称性,特别是手征对称性所施加的约束。在这里,我们表明,在精确到结合能的$\leq\!2\%$的量子蒙特卡罗计算中,两体和三体手征相互作用分别在两个和三个核子扇区中拟合{ \sl only}到束缚态和散射态观测值,导致对质量范围为$A\,$ = $\,$ 4-的原子核的能级和能级排序的预测。12与实验数据非常吻合。我们的研究结果为基本模型的基本假设提供了强有力的支持,并为其系统地应用于这些系统的电弱结构和响应以及更复杂的核铺平了道路。

英文摘要:

A major goal of nuclear theory is to explain the spectra and stability of nuclei in terms of effective many-body interactions amongst the nucleus' constituents-the nucleons, i.e., protons and neutrons. Such an approach, referred to below as the basic model of nuclear theory, is formulated in terms of point-like nucleons, which emerge as effective degrees of freedom, at sufficiently low energy, as a result of a decimation process, starting from the fundamental quarks and gluons, described by Quantum Chromodynamics (QCD). A systematic way to account for the constraints imposed by the symmetries of QCD, in particular chiral symmetry, is provided by chiral effective field theory, in the framework of a low-energy expansion. Here we show, in quantum Monte Carlo calculations accurate to $\leq\!2\%$ of the binding energy, that two- and three-body chiral interactions fitted {\sl only} to bound- and scattering-state observables in, respectively, the two- and three-nucleon sectors, lead to predictions for the energy levels and level ordering of nuclei in the mass range $A\,$=$\,$4-12 in very satisfactory agreement with experimental data. Our findings provide strong support for the fundamental assumptions of the basic model, and pave the way to its systematic application to the electroweak structure and response of these systems as well as to more complex nuclei.

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。

↑