International collaboration on the vacuum structure of full QCD using large-scale parallel computers

点击翻译按钮获取中文摘要

The following results have been obtained mainly from Monte-Carlo simulation studies using SR8000 at KEK and SX7 at RIKEN :(1)DIK group study of finite-tenperature full QCD :International collaboration with DESY and ITEP groups. The phase transition temperature is determined on lattices of 16^3X8 and 24^3X10 using an 0(alpha) improved clover fermion action with Nf=2 light quarks. Using the previos data at Nt=4 and Mt=6,we have obtained for the first time the phase transition temperature in the chiral and the continuum limits, although the quark mass used is not light enough. We are continuing the simulations at lighter quark masses using a new BlueGene maschine at KEK.(2)Gauge invariance of the confinement mechanism :Confinement is a physical phenomenon and so there must be a gauge-invariant mechanism explaining confinement. Up to now abelian projection methods using some non-local gauges can explain the confinement beautifully as the dual Meissner effect.Using SX7 at Riken and performing an extensive Monte-Carlo simulations, we have found even in Landau gauge, the abelian dual Meissner effect works good. However in the gauge, there are no abelian monopoles, but instead the magnetic displacement currents squeezes the electric field.This kind of picture is expected to work in general and so we are doing simulations in various local gauges (known as a bad gauge) to check the expectation.