Speaker
Norikazu Yamada
(KEK)
Description
We propose a subvolume method to study the $\theta$ dependence of the free
energy density of the four-dimensional SU($N$) Yang-Mills theory on the lattice.
As an attempt, the method is first applied to SU(2) Yang-Mills theory at
$T=1.2\,T_c$ to understand the systematics of the method. We then proceed to
the calculation of the vacuum energy density and obtain the $\theta$ dependence,
at least, to $\theta\sim\pi$. The numerical results combined with the theoretical
requirements provide the evidence for the spontaneous CP violation at $\theta = \pi$,
which is in accordance with the large $N$ prediction and in contrast to the CP$^1$
model in two dimensions.
Primary authors
Norikazu Yamada
(KEK)
Prof.
Masahito Yamazaki
(Kavli IPMU, University of Tokyo)
Ryutaro Matsudo
(Chiba University)
Prof.
Ryuichiro Kitano
(KEK)
