Charm quark
From Freepedia
The charm quark is a second-generation quark with a charge of +(2/3)e. It is the third most massive of the quarks, at 1.3 GeV (a bit more than the mass of the proton). It was predicted in 1970 by Sheldon Glashow, John Iliopoulos, and Luciano Maiani, and first observed in 1974, with the discovery of the J/ψ charm particle at the SLAC by a group led by Nobel Prize-winning and American physicist Burton Richter.
Hadrons containing charm quarks
Some of the hadrons containing charm quarks include:
- D mesons contain a charm quark (or its antiparticle) and an up or down quark.
- Ds mesons contain a charm quark and a strange quark.
- There are many charmonium states, for example the J/ψ. These consist of a charm quark and its antiparticle.
- Charmed baryons have been observed, and are named in analogy with strange baryons (e.g. Λc+).
| edit | |
| Fermions: Quarks | Leptons | |
| Quarks: Up | Down | Strange | Charm | Bottom | Top | |
| Leptons: Electron | Muon | Tau | Neutrinos | |
| Gauge bosons: Photon | W+, W- and Z0 bosons | Gluons | |
| Not yet observed: Higgs boson | Graviton | Other hypothetical particles | |
