*** Welcome to piglix ***

November Revolution (physics)

J/ψ
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

5.5208×10−27 kg

3.096916 GeV/c2
Electric charge e
Spin 1

5.5208×10−27 kg

The
J/ψ
(J/psi) meson /ˈ ˈs ˈmzɒn/ 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 3.0969 GeV/c2, just above that of the
η
c
(2.9836 GeV/c2), and a mean lifetime of 7.2×10−21 s. This lifetime was about a thousand times longer than expected.


...
Wikipedia

...