Topological term and nonperuturbative fluctuations
Project/Area Number  10640276 
Research Category 
GrantinAid for Scientific Research (C).

Section  一般 
Research Field 
素粒子・核・宇宙線

Research Institution  Saga University 
Principal Investigator 
YONEYAMA Hiroshi Saga University, Faculty of Science and Technology, Professor, 理工学部, 教授 (50210795)

CoInvestigator(Kenkyūbuntansha) 
IMACHI Masahiro Yamagata University, Faculty of Science, Professor, 理学部, 教授 (70037208)

Project Fiscal Year 
1998 – 1999

Project Status 
Completed(Fiscal Year 1999)

Budget Amount *help 
¥2,900,000 (Direct Cost : ¥2,900,000)
Fiscal Year 1999 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1998 : ¥2,300,000 (Direct Cost : ¥2,300,000)

Keywords  Lattice field theory / Topological term / Phase Structure / Monte Carlo simulation / Topology / Topological charge / Fixed point action / 格子上の場の理論 / トポロジー / トポロジカル項 / 数値シミュレーション / 相構造 / 固定点作用 / トポロジカル電荷 / テータ項 / スケーリング / CP(N1)模型 / strong CP 
Research Abstract 
Topology is expected to play an important role in the dynamics of QCD. It is an important issue to study nonperturbatively a topological term. In this research, we study CP (N1) model with topological term by means of Monte Carlo simulations. In order to perform simulations for the complex Bo1tzmann weight, we adopt a method by which topological charge distribution P (Q) is measured. This method produces in some cases the flattening behaviors of the free energy as a function of theta. We find that the flattening is attributed to errors in calculating P (Q). We also compute the CP (N1) model with fixed point action in order to study the continuum feature. For CP (3) case, P (Q), free energy and correlation lengths show very nice scaling behaviors.

Report
(4results)
Research Output
(4results)