$Z'$ search in non-minimal Universal Extra Dimensions: two bumps and interference

TL;DR

This paper explores the detection prospects of two closely spaced $Z'$ bosons in non-minimal Universal Extra Dimensions at the LHC, highlighting unique features like dual resonances and large couplings due to extra-dimensional profile overlaps.

Contribution

It introduces the possibility of two nearby $Z'$ resonances and emphasizes the importance of interference effects and proper propagator treatment in analyzing such signals.

Findings

Two $Z'$ candidates can exist close in mass.

Effective couplings to SM fermions can be significantly large.

Interference effects are crucial for accurate resonance analysis.

Abstract

We discuss prospects of the $Z'$ search at the LHC in non-minimal Universal Extra Dimensions with tree-level brane-local terms in five dimensions. In this scenario, we find two major differences from the usual $Z'$ physics: (i) two $Z'$ candidates close-by in mass exist; (ii) the effective couplings to the SM fermions could be very large due to drastic overlapping of their profiles along the extra dimension. To evaluate the actual situation precisely, we reconsider the important issues of resonant processes, i.e., treatment of resonant propagators and including interference effects.