Аннотация:

Our research project aims to demonstrate the impacts of monopoles and instanton creations on color confinement, chiral symmetry breaking, and observables that experiments can detect. Monopoles cause color confinement through condensations in the QCD vacuum, and instantons induce chiral symmetry breaking. The monopoles and instantons are closely tied to one another and interact among quarks and gluons in the QCD vacuum. To reveal the relations and interactions among them, we perform simulations of lattice gauge theory.

First, we add a pair of monopole and anti-monopole to the gauge field configurations by applying the monopole creation operator to the vacuum. We vary the magnetic charges of the monopole and anti-monopole to increase the number of monopoles and anti-monopoles and confirm that the additional monopoles and anti-monopoles create instantons and anti-instantons.

We then calculate the observables using the configurations and the eigenvalues and eigenvectors of the overlap Dirac operator that preserves the exact chiral symmetry in lattice gauge theory. We have revealed the quantitative relations by increasing the number density of the instantons and anti-instantons as follows: the chiral condensate which is defined as a negative value decreases. The light quark masses and masses and decay constants of pion and kaon increase. We have found the catalytic effect in which the lifetime of the charged pion becomes shorter than the experimental outcome [1]. Furthermore, we have demonstrated that the finite lattice volume and the discretization do not influence our outcomes [2]. We have shown the preliminary results that the eta-prime meson mass becomes heavy with an increasing number of instantons and anti-instantons [3].

In this seminar, I will give a talk on the results that were recently obtained in my research project.

Литература:

[1] M. Hasegawa, Monopole and instanton effects in QCD, JHEP 09 (2020) 113.
[2] M. Hasegawa, Color confinement, chiral symmetry breaking, and catalytic effect induced by monopole and instanton creations, [arXiv: 2203.11357] (submitted to the EPJC in March 2022).
[3] M. Hasegawa, Instanton effects on chiral symmetry breaking and hadron spectroscopy, PoS (LATTICE 2021) 397 [arXiv: 2201.00431].