Low energy physics and left-right symmetry. Bounds on the model parameters

Abstract

In any gauge model with spontaneous symmetry breakdown the gauge boson masses and their mixings are not independent quantities. They are interconnected through the vacuum expectation values (VEVs) of the Higgs sector. We discuss the low-energy experiments, namely electron-hadron, neutrino-hadron and neutrino-electron processes in the frame of the Manifest Left-Right Symmetric model and show the impact of these dependencies on the possible heavy gauge boson masses and mixings. At 90 % C.L., we obtain $M_{Z_2} \geq 1475$ GeV for phenomenologically favorable models, without $W_L-W_R$ mixing and $M_{Z_2} \geq 1205$ GeV in the other extreme case when a maximal mixing is possible. If we consider the \lr parameters without any constraints from the Higgs sector these limits get down to 410 GeV. Bounds on the Z_2 mixing angle as well as the W_2 mass and its mixing angle are also given.