Are Neutrinos Their Own Antiparticles?

The discovery of finite neutrino masses has been the highlight of particle physics over the past twenty years.    Somewhat ironically such a discovery, through the observation of the phenomenon of neutrino oscillations, only provides a value for the neutrino mass differences, leaving the absolute magnitude of neutrino masses unknown.    I will describe the efforts in progress to directly measure the neutrino mass scale.    Most of these efforts rely on the quantum nature of neutrinos to be of a novel type, in which the distinction between particles and antiparticles is somewhat blurred.    Therefore a discovery in this field will not only provide a value for the neutrino mass scale but will also introduce to the world another peculiar behavior of these unusual particles.