Is neutrino its own antiparticle?

Neutrino is a neutral spin ½ particle, discovered through nuclear beta decay, that interacts only through the weak interaction. It is now well established that neutrinos have mass. The mass and nature of neutrinos play an important role in theories beyond the Standard Model. Whether neutrino is its own anti-particle, as proposed by Majorana, is still an open question. At present, neutrinoless double beta decay (0νββ) is perhaps the only experiment that can reveal the true nature of the neutrinos. Given its significance, there is a widespread interest in the quest for 0νββ employing different techniques. This article presents a brief overview of 0νββ experiments and highlights the indigenous effort to search for 0νββ in ¹²⁴Sn using a cryogenic bolometer at the India - based Neutrino Observatory. (author)