Since the very early days of discovery of radioactivity in atomic nuclei, the neutrino
has played a vital role. In particular, the neutrino: an evasive, electrically neutral, spin 1/2
particle, initially assumed to be massless, led to the understanding of the beta decay, weak
interaction process which violates parity. Today, the neutrino has opened up fresh avenues
beyond the standard model of particles physics. Over the last decade or so, studies on the
atmospheric and solar neutrino oscillation data, have established that neutrinos have a very
tiny mass. This leads us to one of the key questions, namely, whether the neutrino has a
distinct antiparticle (Dirac) or is its own antiparticle (Majorana)? The nuclear double beta
decay is very rare, second order weak interaction process and occurs when single beta decay
is forbidden. Both, the nuclear beta decay and double beta decay can provide the information
on the mass of the neutrinos. At present, neutrino-less double beta decay is perhaps the only
experiment that can tell us whether the neutrino is a Dirac or a Majorana particle. Given the
significance of the 0nu2beta, there is a widespread interest for these rare event studies employing
a variety of novel techniques. This talk will briefly review the current experiments and
present some of the future proposals expected to achieve very high sensitivity.
With the upcoming INO underground laboratory in India, a multi-institutional effort to
carry out an underground neutrino-less double beta decay (0nu2beta) experiment was initiated. A
crucial criterion for detector design is high energy resolution for a precision measurement of
the sum energy of two electrons emitted in 0nu2beta decay. The low temperature bolometric
detectors are ideally suited for this purpose. It was decided to focus on the feasibility of a Sn
cryogenic bolometric detector operating at 10 mK, for the study of 0nu2beta in 124Sn. The
preliminary R&D efforts for this experiment are being done at TIFR and the setup comprising
a cryogen-free, high capacity, 3He−4He dilution refrigerator. The experiment is highly
interdisciplinary spanning nuclear and particle physics and condensed matter physics, and
requires an expertise in a variety of techniques and tools, such ultra-low temperature,
metallurgy and material science, isotope separation, semi-conducting materials and device
fabrication, digital signal processing, etc. This talk will highlight the challenges in the R&D
efforts towards the development of the cryogenic Sn bolometer for the study of 0nu2beta in 124Sn.