AMoRE Experiment Sets New Benchmark in Neutrinoless Double Beta Decay Research

The latest phase of the AMoRE (Advanced Mo-based Rare Process Experiment) project has yielded significant findings in the search for neutrinoless double beta decay, a process that could redefine understanding of fundamental particle physics. Conducted at the Yangyang Underground Laboratory in Korea, the study involved the use of molybdate scintillating crystals at extremely low temperatures to detect this elusive nuclear event. While no clear evidence was observed, the research has set a new upper limit on the decay halflife of molybdenum-100, refining the parameters for future experiments in the field.

New Constraints Established

According to the study published in Physical Review Letters, the AMoRE collaboration utilised multiple kilograms of molybdenum-100, a radioactive isotope, in the form of scintillating crystals. The experiment aimed to detect whether two neutrons in a nucleus could decay into two protons without emitting neutrinos, a phenomenon that would confirm the neutrino and antineutrino as identical particles. Detection of this process is considered crucial for exploring matter-antimatter asymmetry in the universe.

In an interview with Phys.org, Yoomin Oh, corresponding author of the study, explained that the neutrino is one of the elementary particles in the Standard Model. It was ‘invented’ by Wolfgang Pauli about a hundred years ago and discovered a couple of decades later than that. He added that while neutrinos are among the most abundant particles, their properties, including mass, remain largely unknown.

Next Phase: AMoRE-II at Yemilab

AMoRE-I achieved the highest sensitivity ever recorded for detecting neutrinoless double beta decay in molybdenum-100, but no definitive signal was found. This outcome has refined the experimental approach, with the next phase, AMoRE-II, currently being developed at Yemilab, a newly constructed underground research facility in Korea.

The upcoming phase will involve a significantly larger quantity of molybdenum-based crystal detectors and an upgraded low-temperature detection system. The AMoRE collaboration aims to achieve an even lower background environment, enhancing the sensitivity of the experiment. Data collection for AMoRE-II is expected to begin within the next year, with researchers hoping to uncover new insights into the nature of neutrinos.