$P_5'$ Anomaly for Top: $tZ'$ Production at LHC

TL;DR

This paper investigates the potential for discovering a $Z'$ boson linked to the $P_5'$ anomaly through top-associated production processes at the LHC, highlighting new production channels and their experimental prospects.

Contribution

It introduces novel top-associated production channels for a $Z'$ boson related to the $P_5'$ anomaly, including $cg o tZ'$ and $car c o Z'$, within a $L_ - L_ au$ model with vector-like quarks.

Findings

Potential to probe $Z'$ with current LHC Run 2 data.

Discovery prospects extend to HL-LHC.

New production channels enhance search strategies.

Abstract

The $P_5'$ anomaly uncovered by the LHCb experiment in $B \to K^*\mu\mu$ angular observables has motivated a possible $Z'$ boson that couples to left-handed $b \to s$ transitions, where a model would be gauged $L_\mu - L_\tau$ symmetry, but direct search for such a $Z'$ is not promising. Less constrained is an analogous $Z'$ coupling to right-handed $t \to c$ transitions. Motivated by this, we study $cg \to tZ'$ associated production at LHC, both for a generic model, and in $L_\mu - L_\tau$ with a vector-like U quark. We also study $c\bar c \to Z'$ production that exists within the model. Both processes can be probed already with LHC Run 2 data, all the way up to the HL-LHC with discovery potential.