The AMoRE experiment in South Korea has reported no evidence of neutrinoless double beta decay (0vßß), but its findings impose strict limits on this elusive subatomic process.

About the AMoRE Experiment

• The AMoRE (Advanced Mo-based Rare Process Experiment) is an international collaboration focused on searching for neutrinoless double beta decay (0νββ) using molybdenum-based crystals.
  • These crystals are cooled to near absolute zero and are  ideal for studying double beta decay.
• This research is crucial in determining whether neutrinos are Majorana particles—a discovery that could reshape our understanding of fundamental physics.

Key Findings of the AMoRE Experiment

• The experiment did not detect evidence of 0vßß.
• However, it set a strict limit: if 0vßß exists, Mo-100 nuclei would take at least 10²⁴ years to decay.
• The results suggest that the neutrino mass is likely below 0.22–0.65 billionths of a proton.
• The findings do not prove that neutrinos are massless but indicate a gap in the Standard Model of Particle Physics.

Understanding Beta Decay

• Beta decay is a process by which unstable atomic nuclei release excess energy to become more stable. 
• This can occur in three forms:
  • Beta-minus decay: A neutron converts into a proton, emitting an electron and an anti-neutrino.
  • Beta-plus decay: A proton converts into a neutron, emitting a positron and a neutrino.
  • Double beta decay: Two neutrons simultaneously convert into two protons, emitting two electrons and two anti-neutrinos.

Neutrinoless Double Beta Decay (0vßß)

• Scientists are searching for a special variant of beta decay—neutrinoless double beta decay (0vßß).
  • In neutrinoless double beta decay (0vßß) only two electrons are emitted, without any anti-neutrinos. 
• This can happen only if neutrinos are their own anti-particles (Majorana particles).

Significance of Detecting Neutrinoless Double Beta Decay (0vßß) 

• It would confirm that neutrinos are Majorana particles.
• Help determine their exact masses.
• Challenge the Standard Model of Particle Physics, which assumes neutrinos are massless.