Studies of matter in neutron stars by using lattice quantum chromodynamics

2016 Fiscal Year Final Research Report

• Project/Area Number: 26400279
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Saga University
• Principal Investigator: Kouno Hiroaki 佐賀大学, 工学(系)研究科(研究院), 教授 (80234706)
• Co-Investigator(Renkei-kenkyūsha): Yahiro Masanobu 九州大学, 理学研究科, 教授 (40300537) ; Nakamura Atsushi 大阪大学, 核物理研究センター, 協同研究員 (30130876)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 格子量子色力学 / 中性子星 / バリオン数 / アイソスピン / 虚数化学ポテンシャル / 現象論模型

Outline of Final Research Achievements

Quark matter is expected to exist in neutron stars. Theoretically, quark matter is studied by using the lattice quantum chromodynamics on the 4-dimesional discrete lattice in computer. The method is called "lattice QCD (LQCD)". When there is no unbalance between particle and antiparticle, the method of LQCD is almost established. However, due to the so called "sign problem", LQCD is not feasible when the number of particle is much larger than that of antiparticles. In this research, we have done the LQCD simulations under the situation with the real isospin and imaginary quark (or baryon) number chemical potentials.
The LQCD under the situation does not correspond to the situation in real physical world, but is feasible, since the sign problem is absent. From the results of the simulations, we have tried to get information of the situation which is realized in neutron stars.

Free Research Field

原子核理論（理論核物理）