Chameleon Vector Bosons

TL;DR

This paper introduces a chameleon mechanism for vector bosons, where their effective range and strength depend on environmental factors, potentially weakening astrophysical constraints and allowing for detectable long-range forces under certain conditions.

Contribution

It demonstrates how a light charged scalar can induce a chameleon effect in vector bosons, altering their apparent range and strength based on source density and proximity, which is a novel screening mechanism.

Findings

Chameleonic vector bosons can evade certain astrophysical constraints.

Casimir measurements limit strong B-L forces above 0.1 microns.

A long-range B-L force could exist with an effective range less than a micron near Earth.

Abstract

We show that for a force mediated by a vector particle coupled to a conserved U(1) charge, the apparent range and strength can depend on the size and density of the source, and the proximity to other sources. This "chameleon" effect is due to screening from a light charged scalar. Such screening can weaken astrophysical constraints on new gauge bosons. As an example we consider the constraints on chameleonic gauged B-L. We show that although Casimir measurements greatly constrain any B-L force much stronger than gravity with range longer than 0.1 microns, there remains an experimental window for a long range chameleonic B-L force. Such a force could be much stronger than gravity, and long or infinite range in vacuum, but have an effective range near the surface of the earth which is less than a micron.