Composition |
c c |
---|---|
Statistics | Bosonic |
Interactions | Strong, weak, electromagnetic force, gravity |
Symbol | J/ψ |
Antiparticle | Self |
Discovered |
SLAC: Burton Richter et al. (1974) BNL: Samuel Ting et al. (1974) |
Mass |
×10−27 kg 5.5208 |
Electric charge | 0 e |
Spin | 1 |
×10−27 kg 5.5208
The
J/ψ
(J/psi) meson /ˈdʒeɪ ˈsaɪ ˈmiːzɒn/ or psion is a subatomic particle, a flavor-neutral meson consisting of a charm quark and a charm antiquark. Mesons formed by a bound state of a charm quark and a charm anti-quark are generally known as "charmonium". The
J/ψ
is most common form of charmonium, due to its low rest mass. The
J/ψ
has a rest mass of GeV/c2, just above that of the 3.0969
η
c (GeV/c2), and a 2.9836 mean lifetime of ×10−21 s. This lifetime was about a thousand times longer than expected. 7.2