Updated Parameter Limits of the Left-Right Symmetric Model

Abstract

Bounds of the neutral current sector parameters of the left-right symmetric model are investigated taking into account the low-energy data, LEP-data and CDF-result for the top mass $m_t=174\pm 10^{+13}_{-12}$. It is found that in the case of the minimal scalar sector with a left- and a right-handed triplet and a bidoublet Higgses the mass of the heavy neutral gauge boson $M_{Z'}$ should be larger than 1.2 TeV, assuming equal left- and right-handed gauge couplings and a negligible VEV of the left-handed triplet. For larger values of the ratio $g_L/g_R$ smaller values of $M_{Z'}$ are allowed.