An Effective Z'

TL;DR

This paper introduces a method to couple Z' gauge bosons to the Standard Model via effective operators, enabling flexible interactions without altering SM structure or introducing anomalies, and explores its implications for recent anomalies and dark matter.

Contribution

It presents a novel approach to coupling Z' bosons through effective operators from simple extensions, avoiding anomalies and non-standard representations.

Findings

Effective Z' models can explain recent anomalies such as the D0 dimuon asymmetry and CDF excesses.

The method allows complete control over Z' couplings without modifying SM couplings.

Implications for dark matter phenomenology are discussed.

Abstract

We describe a method to couple Z' gauge bosons to the standard model (SM), without charging the SM fields under the U(1)', but instead through effective higher dimension operators. This method allows complete control over the tree-level couplings of the Z' and does not require altering the structure of any of the SM couplings, nor does it contain anomalies or require introduction of fields in non-standard SM representations. Moreover, such interactions arise from simple renormalizable extensions of the SM - the addition of vector-like matter that mixes with SM fermions when the U(1)' is broken. We apply effective Z' models as explanations of various recent anomalies: the D0 same-sign dimuon asymmetry, the CDF W+di-jet excess and the CDF top forward-backward asymmetry. In the case of the W+di-jet excess we also discuss several complementary analyses that may shed light on the nature of the discrepancy. We consider the possibility of non-Abelian groups, and discuss implications for the phenomenology of dark matter as well.