北大核科学论坛第319期

报告题目:New Developments in Nuclear Lattice EFT
报告人:  Professor Ulf-G. Meißner (Universität Bonn & Forschungszentrum Jülich)
时间: 2017年5月8日(周一)下午3:30
地点: 北京大学物理学院7802会议室(西217)
报告摘要:
Nuclear lattice effective field theory is a new approach for ab initio calculations of strongly interacting fermion systems. I give an introduction of the underlying concepts and review
the results obtained so far. Then, I discuss in more detail two recent developments. First, the nucleon-nucleon interaction at next-to-next-to-leading order in the chiral expansion is studied as
a function of the lattice spacing a. It is shown that the physics is independent of a when varied in the range from 1…2 fm. Second, I present lattice Monte Carlo calculations based on chiral
effective field theory for the ground states of helium, beryllium, carbon, and oxygen isotopes. By computing model-independent measures that probe three- and four-nucleon correlations at
short distances, the effective number of alpha clusters in any nucleus as well as their shape compared to alpha particles in vacuum can be determined. I also discuss a new computational
approach called the pinhole algorithm, which solves a long-standing deficiency of auxiliary-field Monte Carlo simulations in computing density correlations relative to the center of mass.
Using this algorithm, the proton and neutron density distributions and the geometry of cluster correlations in 12C, 14C, and 16C are computed.
联系人:孟杰(mengj@pku.edu.cn)