Implications of the muon anomalous magnetic moment in a Doublet Left-Right Symmetric Model

TL;DR

This paper calculates one-loop contributions to the muon g-2 in a Doublet Left-Right Symmetric Model, constraining new particle masses based on experimental bounds and gauge coupling assumptions.

Contribution

It provides a comprehensive one-loop analysis of muon g-2 in the DLRSM, including extended gauge bosons, scalars, and heavy neutrinos, with bounds on their masses.

Findings

Lower bounds on $W'$ and $Z'$ masses are established based on muon g-2 constraints.

Excluding $v_R o 1$ TeV is incompatible with the muon g-2 experimental bounds.

Relaxing gauge coupling equality tightens the bounds on new gauge boson masses.

Abstract

We compute the complete set of one-loop contributions to the muon anomalous magnetic moment, $a_{\mu}=(g-2)_{\mu}/2$, in the Doublet Left-Right Symmetric Model (DLRSM), based on the gauge group $SU(2)_{L}\otimes SU(2)_{R}\otimes U(1)_{B-L}$ with neutrino masses generated via the inverse seesaw (ISS) mechanism. We evaluate all four one-loop topologies VFF, SFF, FVV, and FSS arising from the extended gauge bosons ($W^{\prime}$, $Z^{\prime}$), the new scalar sector ($H_{3}^{0}$, $A_{1}^{0}$, $H_{R}^{\pm}$, $H_{L}^{\pm}$), and the heavy neutrino spectrum generated by the ISS mechanism, using the Casas--Ibarra parametrization to express the neutrino mixing in terms of physical observables. Imposing the experimental bound on $\Delta a_{\mu}$, we establish that $v_{R}\lesssim1$ TeV is excluded, implying lower bounds $m_{W^{\prime}}\gtrsim325$ GeV, $m_{Z^{\prime}}\gtrsim385$ GeV, and $m_{N}\gtrsim700$ GeV under the manifest left-right symmetry condition $g_{R}=g_{L}$. Relaxing this condition to $g_{R}\neq g_{L}$ strengthens the gauge boson bounds to $m_{W^{\prime}}\gtrsim1625$ GeV and $m_{Z^{\prime}}\gtrsim1650$ GeV.