Theoretical constraints on masses of heavy particles in Left-Right Symmetric Models

TL;DR

This paper analyzes the scalar mass spectra and theoretical constraints in Left-Right symmetric models with TeV-scale particles, focusing on unitarity, vacuum stability, and flavor-changing neutral current bounds, and provides renormalization group evolutions.

Contribution

It offers a comprehensive analysis of scalar mass spectra under theoretical constraints and relates heavy particle masses to the right-handed triplet VEV, including RG evolutions at 1-loop.

Findings

Scalar masses around TeV scale are consistent with unitarity and stability.

Lower bounds on heavy gauge boson masses are derived from scalar mass spectra and FCNC bounds.

Most scalar couplings hit Landau poles near 10^{6.5} GeV, indicating potential theoretical limitations.

Abstract

Left-Right symmetric models with general $g_L \neq g_R$ gauge couplings which include bidoublet and triplet scalar multiplets are studied. Possible scalar mass spectra are outlined by imposing Tree-Unitarity, and Vacuum Stability criteria and also using the bounds on neutral scalar masses $M_{\rm H^{ FCNC}}$ which assure the absence of Flavour Changing Neutral Currents (FCNC). We are focusing on mass spectra relevant for the LHC analysis, i.e., the scalar masses are around TeV scale. As all non-standard heavy particle masses are related to the vacuum expectation value (VEV) of the right-handed triplet ($v_R$), the combined effects of relevant Higgs potential parameters and $M_{\rm H^{ FCNC}}$ regulate the lower limits of heavy gauge boson masses. The complete set of Renormalization Group Evolutions for all couplings are provided at the 1-loop level, including the mixing effects in the Yukawa sector. Most of the scalar couplings suffer from the Landau poles at the intermediate scale $Q \sim 10^{6.5}$ GeV, which in general coincides with violation of the Tree-Unitarity bounds.