From the
IceCube experiment
, an observatory buried in the ice of
Antarctica
that hunts down the most elusive of particles,
neutrinos
, the confirmation of a 60-year-old theory on the mysterious antineutrinos, the
antimatter
counterpart
of neutrinos.
It is a
rare interaction
, called
resonance
, a phenomenon predicted in
1960
by the Nobel
Sheldon Glashow
.
This is what emerges from the study published in the journal Nature by the IceCube collaboration, a consortium of more than 400 researchers from 53 institutions in 12 countries based at the American University of Wisconsin-Madison.
"The observation of IceCube - says to ANSA one of the authors of the study, Elisa Bernardini, from the University of Padua - provides independent proof of the validity of the Standard Model of particle physics", the architrave to describe how it is Nature in its most intimate constituents.
The IceCube physicists analyzed, in particular, an event starring an
electronic antineutrino
, one of the three families of this type of particles, coming from the cosmos and captured in December 2016 by the thousands of IceCube sensors, in operation since 2011.
According to Glashow's theory, an antineutrino can interact with an electron to give rise to a particle not yet discovered when the theory was proposed, the
W boson
, through a process known as resonance.
“The key - explains Bernardini - is that it is a special neutrino, an
electronic antineutrino
, and that this has a precise energy.
That is, it must reach the value of 6.3 petaelectron volts (PeV) ”, or
6.3 million billion electron volts
, a figure with 15 zeroes.
“Such a high energy - he specifies - cannot be reached by today's particle accelerators, such as the Large Hadron Collider (Lhc) of CERN, or of the next generation.
However, according to current models, astrophysical phenomena can produce neutrinos of such high energies.
The observation of IceCube - he concludes - therefore represents a turning point for neutrino astrophysics.
It is like a fingerprint in the flux of cosmic neutrinos, which will be useful to distinguish between the possible astrophysical mechanisms that produce these evanescent particles ”.