Impact of extra particles on indirect Z' limits

TL;DR

This paper explores how adding extra particles like vector bosons and scalars can weaken the indirect experimental limits on hypothetical Z' bosons, potentially making them less constrained than current collider bounds.

Contribution

It demonstrates that the indirect limits on Z' bosons can be systematically relaxed through the strategic addition of new particles, challenging previous assumptions about their robustness.

Findings

Adding vector bosons and scalars can weaken indirect Z' limits

The weakened limits can fall below current collider bounds

The robustness of existing limits depends on particle interactions

Abstract

We study the possibility of relaxing the indirect limits on extra neutral vector bosons by their interplay with additional new particles. They can be systematically weakened, even below present direct bounds at colliders, by the addition of more vector bosons and/or scalars designed for this purpose. Otherwise, they appear to be robust.