Bilepton contributions to the neutrinoless double beta decay in the   economical 3-3-1 model
  Possible contributions of the bilepton to the neutrinoless double beta $(\beta\beta)_{0\nu}$ decay in the economical 3-3-1 model are discussed. We show that the $(\beta\beta)_{0\nu}$ decay in this model is due to both sources--Majorana $<M_{\nu}>_{L}$ and Dirac $<M_{\nu}>_{D}$ neutrino masses. If the mixing angle between charged gauge bosons, the standard model $W$ and bilepton $Y$, is in range of the ratio of neutrino masses $<M_{\nu}>_{L}/< M_{\nu}>_{D}$, both the Majorana and Dirac masses simultaneously give contributions dominant to the decay. As results, constraints on the bilepton mass are also given. 
Dang Van Soa, Phung Van Dong, Trinh Thi Huong and Hoang Ngoc Long