格点有效场论中轻核性质的重整化群不变性  

Renormalization group invariance of light nuclei in lattice effective field theory

作　　者：邓宝阁 马远卓 吕炳楠 DENG Bao-Ge;MA Yuan-Zhuo;LU Bing-Nan(Institute of Theoretical Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Facility for Rare Isotope Beams,Michigan State University,East Lansing 48824,USA;Graduate School of China Academy of Engineering Physics,Beijing 100193,China)

机构地区：[1]中国科学院理论物理研究所,北京100190 [2]中国科学院大学物理学院,北京100049 [3]密歇根州立大学稀有同位素束设施,美国东兰辛48824 [4]中国工程物理研究院研究生院,北京100193

出　　处：《中国科学：物理学、力学、天文学》2024年第9期101-111,共11页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(编号:12275259);国家自然科学基金委员会-中国工程物理研究院NSAF联合基金(编号:U2330401)资助。

摘　　要：格点有效场论是原子核第一性原理计算的重要方法之一.它将手征有效场论与蒙特卡罗方法结合,从单核子自由度出发严格求解原子核多体问题.实际计算中,人们需要对手征有效核力进行正规化,引入有限的动量截断以消除发散.原则上最终计算结果应不依赖于人为设定的截断尺度,换言之,有效场论计算应具有重整化群不变性.但与此预期相反,近年来很多使用手征有效核力的计算中,发现结果较敏感地依赖于动量截断.本文将结合近年来发展的微扰量子蒙卡方法,基于格点有效场论,研究动量截断对^(3)H,^(4)He与^(16)O基态性质的影响.针对不同的动量截断构造了对应的手征核力,系统计算了这些原子核的基态能量、基态电荷分布与均方根半径.我们发现相比常用的非定域正规化方案,本文所使用的格点正规化方案能够很好地消除结果的动量截断依赖性.The nuclear lattice effective field theory(NLEFT) is an important method for nuclear ab initio calculations. The NLEFT combines the chiral effective field theory and the Monte Carlo method to exactly solve the nuclear many-body problem starting from the single nucleon degree of freedom. In numerical calculations of NLEFT, we should regularize the chiral effective nuclear force and introduce a finite momentum cutoff to eliminate unphysical divergences. In principle, the results of NLEFT should not depend on this cutoff scale. In other words, the effective field theory calculations should respect renormalization group invariance. By contrast, in recent years, many calculations using chiral effective nuclear forces have found that the results are sensitive to the momentum cutoff. In this article, we will employ the perturbative quantum Monte Carlo method and study the influence of the momentum cutoff on the ground-state properties of ^(3)H,^(4)He,and ^(16)O. We construct chiral nuclear forces corresponding to different momentum cutoffs and systematically calculate the ground-state energy, ground-state charge distribution, and root-mean-square radius of these nuclei. We find that the lattice regularization scheme is advantageous in eliminating the momentum cutoff dependencies of the results than the commonly used nonlocal regularization schemes.

关 键 词：格点有效场论 核结合能 电荷半径 电荷密度分布 重整化群不变性 

分 类 号：O571[理学—粒子物理与原子核物理]