Color confinement due to spontaneous breaking of magnetic $U(1)_m^8$

TL;DR

This paper investigates the role of magnetic monopoles in color confinement within SU(3) QCD, demonstrating that monopole condensation occurs independently of quark mass and suggesting a continuum limit for monopole behavior.

Contribution

It provides a detailed analysis of Abelian monopoles in SU(3) QCD, including their density, effective action, and behavior under block spin transformations, highlighting their potential role in confinement.

Findings

Monopole condensation occurs due to entropy dominance.

Monopole density and action scale with the blocking parameter, indicating a continuum limit.

Monopole behavior appears independent of quark mass, implying irrelevance to chiral symmetry breaking.

Abstract

The violation of non-Abelian Bianchi identity is equal to 8 Abelian monopole currents of the Dirac type satisfying Abelian conservation rules kinematically. There exist magnetic $U(1)_m^8$ symmetries in non-Abelian $SU(3)$ QCD. When the magnetic $U(1)_m^8$ symmetries are broken spontaneously, only states which are invariant under all $U(1)_e$ subgroups of $SU(3)$ can exist as a physical state. Such states are $SU(3)$ singlets. The QCD vacuum in the confinement phase is characterized by one long percolating monopole loop running over the whole lattice volume in both quenched and full QCD. The long loop in full QCD is on average a few times longer in comparison with that in quenched QCD case. Surprisingly, the monopole behaviors in full QCD seem independent of the bare quark mass suggesting irrelevance of Abelian monopoles to the chiral symmetry breaking mechanism. Existence of such Abelian magnetic monopoles in the continuum limit is studied in detail in $SU(3)$ by means of a block spin transformation of monopoles and the inverse Monte-Carlo method. The monopole density $\rho$ and the infrared effective monopole action $S(k)$ of $n$ blocked monopoles are determined for $a(\beta)=(0.04\sim 2)$fm and $n=1\sim 12$ blockings on $48^4$ lattice in quenched QCD and for $a(\beta)=0.0846(7)$fm and $n=1\sim 24$ on $96^4$ in full QCD at $m_\pi=146$MeV. Originally $\rho$ and $S(k)$ are a two-point function of $a(\beta)$ and the number of times of the blocking transformation $n$. However, both are found to be a function of $b=na(\beta)$ alone in the quenched QCD which suggests the existence of the continuum limit. In the full QCD, the renormalization flow is observed similarly but the scaling is not yet proved. The distributions of the long loops show that monopole condensation occurs due to the entropy dominance over the energy for all $b$ considered.