text: Note that two RH neutrinos are enough to reconcile with the observed neutrino oscillation 
  
  data, with a prediction of one massless light neutrino. Therefore, without introducing any 
  
  additional new dynamical degrees of freedom, the DM particle arises in the minimal gauged 
  
  U(1)B  L model. 
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  The paper is organized as follows. In the next section, we brieﬂy describe our model. In 
  
  section III, we estimate the thermal relic density of the RH neutrino and identify the model 