Neutrinoless Double Beta Decay and $<\eta >$ Mechanism in the Left-Right Symmetric Model

The neutrinoless double beta ($0\nu \beta \beta$) decay is studied in the framework of left-right symmetric model. The coexistence of left and right handed currents induces rather complicated interactions in the mixing of lepton and hadrons, called $<\lambda >$ mechanism and $<\eta >$ mechanism in addition to the conventional effective neutrino mass $<m_{\nu }>$ mechanism. In this letter we indicate the possible magnification of $<\eta >$ mechanism and importance to survey $0\nu \beta \beta$ decay of different nuclei for specifying New Physics beyond the Standard Model.