One explanation for the deficit is that some of the electron antineutrinos
have transformed into an undetectable, lightweight sterile neutrino, about one-millionth the mass of an electron, says Luk.
If neutrinos and their antimatter equivalent, antineutrinos
, oscillate differently, this could provide the explanation.
Neutrinos had been detected but only in the form of antineutrinos
produced by nuclear fission reactors (see 1956).
The beam consists of mostly muon neutrinos of energy around 2.5 GeV and expects a total exposure of 1.47 x [10.sup.21] POT running 3.5 years in neutrino mode and 3.5 years in antineutrino
If a difference were to be found between the rates of oscillations of separate neutrino and antineutrino
beams, that would be proof of the imbalance between matter and antimatter.
"KamLAND was specifically designed to study antineutrinos
. We are able to discriminate them from background noise and detect them with very high sensitivity," added Freedman, a member of Berkeley Lab's Nuclear Science Division and a professor in the Department of Physics at the University of California at Berkeley, leads U.S.
Scientists have long theorized that a "neutrinoless" version - wherein two antineutrinos
(or neutrinos) annihilate each other - also exists.
Each second, more than 10 scptillion ([10.sup.25]) antineutrinos
race away from Earth and into space.
In the l - [[bar.[nu]].sub.l] center-of-mass frame, the four momenta of lepton and antineutrino
pair are given as
For scientists still looking for these particles, the 5 MeV antineutrino
anomaly detected by the NEOS experiment, (http://physicsworld.com/cws/article/news/2016/feb/18/chinese-lab-confirms-antineutrino-anomalies) among others, is, for now, the only hope.
The most important features of neutron decay are described by the formula of Jackson, Treiman, and Wyld , which gives the neutron decay probability as a function of the emitted ([p.sub.e]) and antineutrino
([p.sub.v]) momenta, and the direction of the initial neutron's spin vector ([sigma]):