Light-front $\phi_2^4$ theory with sector-dependent mass

TL;DR

This paper explores sector-dependent bare mass in light-front $_2^4$ theory, analyzing its impact on nonperturbative calculations and critical behavior, with findings indicating limited effects on the lightest state and critical coupling.

Contribution

It introduces sector-dependent bare mass into light-front $_2^4$ theory to improve nonperturbative calculation convergence and examines its effects on critical phenomena.

Findings

Higher Fock sectors have larger probability.

Mass of the lightest state is not significantly affected.

Critical coupling remains largely unchanged.

Abstract

As an extension of recent work on two-dimensional light-front $\phi^4$ theory, we implement Fock-sector dependence for the bare mass. Such dependence should have important consequences for the convergence of nonperturbative calculations with respect to the level of Fock-space truncation. The truncation forces the self-energy corrections to be sector-dependent; in particular, the highest sector has no self-energy correction. Thus, the bare mass can be considered sector dependent as well. We find that, although higher Fock sectors have a larger probability, the mass of the lightest state and the value of the critical coupling are not significantly affected. This implies that coherent states or the light-front coupled-cluster method may be required to properly represent critical behavior.