Vector leptoquark contributions to lepton dipole moments

TL;DR

This paper investigates how TeV-scale vector leptoquarks can influence lepton dipole moments, analyzing parameter spaces against experimental data and LHC bounds, and identifying specific leptoquarks that can explain muon magnetic moment anomalies.

Contribution

It provides a detailed analysis of vector leptoquark parameter spaces, considering LHC constraints and their ability to explain lepton dipole moment anomalies, highlighting the roles of U_1 and V_2 leptoquarks.

Findings

U_1 and V_2 leptoquarks can explain muon g-2 anomaly.

Significant parameter space is excluded by current LHC data.

Current muon EDM measurements do not constrain leptoquark couplings.

Abstract

Leptoquarks (LQs) can contribute to the magnetic and electric dipole moments of charged leptons, which the current experiments have measured with good accuracy. We revisit the parameter spaces of TeV-scale vector LQs that contribute to these observables and study how these models fare against the LHC bounds. We show that significant portions of the parameter space are excluded when the current LHC data is utilised effectively. We find that only $U_1$ and $V_2$ can explain the observed positive shift in $(a_\mu^{\rm exp} - a_\mu^{\rm SM})$ through a lepton chirality-flipping contribution with $\mathcal O(1)$ LQ-quark-lepton coupling. We also see how these two LQs can fit the electron dipole moment and atomic parity violation measurements. We find that the current electric dipole moment measurements of the muon cannot restrain the LQ-quark-lepton couplings within perturbative regions.