Higgs Effect Without Lunch

TL;DR

This paper explores how effective lower-dimensional physics can emerge from higher-dimensional models through nontrivial wavefunction dependence, leading to unconventional gauge symmetry breaking patterns, exemplified by a 5D scalar electrodynamics setup.

Contribution

It introduces a novel mechanism of gauge symmetry breaking arising from coordinate-dependent wavefunctions in non-truncation dimensional reductions, with a concrete 5D scalar electrodynamics example.

Findings

Unusual gauge symmetry breaking patterns can occur without traditional truncations.

Wavefunction factors depending on transverse coordinates influence gauge mode masses.

The mechanism is analogous to effects seen in gravitational braneworld models.

Abstract

Reduction in effective spacetime dimensionality can occur in field-theory models more general than the widely studied dimensional reductions based on technically consistent truncations. Situations where wavefunction factors depend nontrivially on coordinates transverse to the effective lower dimension can give rise to unusual patterns of gauge symmetry breaking. Leading-order gauge modes can be left massless, but naturally occurring Stueckelberg modes can couple importantly at quartic order and higher, thus generating a "covert" pattern of gauge symmetry breaking. Such a situation is illustrated in a five-dimensional model of scalar electrodynamics in which one spatial dimension is taken to be an interval with Dirichlet/Robin boundary conditions on opposing ends. This simple model illuminates a mechanism which also has been found in gravitational braneworld scenarios.