Flavor-changing phenomenology in a $U(1)$ model

TL;DR

This paper explores a $U(1)$ extension of the standard model that introduces flavor-changing neutral currents, explains neutrino masses, and accounts for recent $W$-boson mass deviations, with detailed phenomenological analysis.

Contribution

It proposes a novel family-nonuniversal $U(1)$ model that naturally explains neutrino masses and recent $W$-boson measurements, and analyzes its flavor-changing effects.

Findings

The model predicts significant FCNC effects in meson mixing and decays.

It accounts for small neutrino masses through the new gauge structure.

The model explains the $W$-boson mass deviation observed recently.

Abstract

We investigate a family-nonuniversal Abelian extension of hypercharge, which significantly alters the phenomenological features of the standard model. Anomaly cancellation requires that the third quark family transforms differently from the first two quark families. Additionally, it acquires that three right-handed neutrinos are presented. This model generates naturally small neutrino masses and a $W$-boson mass deviation appropriate to recent measurements. Additionally, the model introduces flavor-changing neutral currents (FCNCs) of quarks coupled to the new gauge boson $Z'$ and new Higgs fields. These FCNCs significantly modify the neutral-meson mixing amplitudes and rare meson decays, which are studied in detail. We also address flavor changing processes in the charged lepton sector.