COMET (Coherent Muon to Electron Transition) is a nuclear physics experiment in
J-PARC
J-PARC (Japan Proton Accelerator Research Complex) is a high intensity proton accelerator facility. It is a joint project between KEK and JAEA and is located at the Tokai campus of JAEA. J-PARC aims for the frontier in materials and life scienc ...
,
Tokai, Japan. In contrast to the usual
muon
A muon ( ; from the Greek letter mu (μ) used to represent it) is an elementary particle similar to the electron, with an electric charge of −1 '' e'' and a spin of , but with a much greater mass. It is classified as a lepton. As wi ...
decay to an
electron
The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family,
and are generally thought to be elementary particles because they have no kn ...
and
neutrino
A neutrino ( ; denoted by the Greek letter ) is a fermion (an elementary particle with spin of ) that interacts only via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass ...
, COMET seeks to look for neutrinoless muon to electron conversion, where the electron flies away with an energy of 104.8 MeV. Muon to electron conversion is not forbidden in the
Standard Model
The Standard Model of particle physics is the theory describing three of the four known fundamental forces (electromagnetism, electromagnetic, weak interaction, weak and strong interactions - excluding gravity) in the universe and classifying a ...
but the branching ratio is about
considering
neutrino oscillations. In
beyond the Standard Model approaches the muon to electron conversion process can be as high as
e.g. via the
supersymmetric
In a supersymmetric theory the equations for force and the equations for matter are identical. In theoretical and mathematical physics, any theory with this property has the principle of supersymmetry (SUSY). Dozens of supersymmetric theories ...
.
COMET will be using a new beamline connecting the J-PARC main ring and the J-PARC Nuclear and particle Physics Experimental Hall (NP hall).
The current spokesperson is
Kuno Yoshitaka alongside project manager Mihara Satoshi. The collaboration consists of universities coming from 15 countries.
See also
*
Mu2e
Mu2e, or the Muon-to-Electron Conversion Experiment, is a particle physics experiment at Fermilab in the US. The goal of the experiment is to identify physics beyond the Standard Model, namely, the conversion of muons to electrons without the e ...
experiment
References
External links
SINDRUMMECO
Particle experiments
Physics beyond the Standard Model
Science and technology in Japan
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