CERN physicists find evidence of rare particle decay after 42 years
The detection of a beauty quark decay could allow researchers to explore the Zeptoverse, a scale involving distances as small as a zeptometre.
Physicists at CERN have detected evidence of an extremely rare subatomic particle decay following more than 40 years of searching, according to Moneycontrol.
The LHCb collaboration identified a process known as 'Bd to mu mu', where a particle containing a beauty quark and a down antiquark decays into two muons. Scientists predict this specific decay happens only once in every 10 billion beauty-particle decays.
The finding was made using the upgraded Large Hadron Collider beauty (LHCb) experiment. Researchers combined data from 2024 and 2025 with observations recorded between 2011 and 2018, using machine-learning techniques to separate the signal from background events.
The result reached a statistical significance of 3.2 sigma, which is the first evidence of this decay from a single experiment. While the measurement aligns with the Standard Model, a five-sigma significance is typically required to claim a formal discovery.
This research may help scientists investigate the Zeptoverse, a scale of nature involving distances as small as a zeptometre. Studying this scale could reveal unknown particles and fundamental forces that have not yet been detected.
Scientists intend to continue collecting data into the early 2030s. A future upgrade could increase the data collection rate by a factor of 10 to search for previously unknown particles.