Theoretical constraints on masses of heavy particles in Left-Right symmetric models

Abstract

Left-Right symmetric models with general gL≠gR 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 MHFCNC 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 (vR), the combined effects of relevant Higgs potential parameters and MHFCNC 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∼106.5 GeV, which in general coincides with violation of the Tree-Unitarity bounds.

Keywords

• Unitarity
• Vacuum stability
• FCNC
• RGEs
• Left-Right symmetry