22 August 2019 – A new study published today reveals the mass of the lightest neutrino, an abundant ‘ghost’ particle found throughout the universe, has been calculated to be at least six million times lighter than the mass of an electron.
It is already known that there are three different types of neutrinos with different masses, but until now little was known about the mass of the lightest neutrino.
This new research, which was part-funded by STFC, was led by Dr Arthur Loureiro of University College London (UCL). He said: “As neutrinos are abundant but tiny and elusive, we needed every piece of knowledge available to calculate their mass and our method could be applied to other big questions puzzling cosmologists and particle physicists alike.”
Being able to understand neutrinos and how they get their mass could help to answer questions including how the universe is held together, why it is expanding and what dark matter is made of.
The concept that neutrinos have mass is a relatively new one, with the discovery in 1998 earning a Nobel Prize for Physics. Even so, the Standard Model used by modern physics has yet to be updated to assign neutrinos a mass.
The international research team, including UCL, have now been able to give an upper limit for the mass of the lightest neutrino for the first time. The particle could technically have no mass as a lower limit is yet to be determined.
To calculate the neutrino’s mass, the team collected data from various cosmological and astronomical sources to create a way to mathematically model the neutrino mass, and used the UCL supercomputer to digest the numbers – using more than half a million computing hours to process the data, equivalent to almost 60 years on a single processor.
For the full press release, visit the UCL website.
Last updated: 27 August 2019