Table of Contents
What is the J particle?
J/ψ mesons (pronounced jeɪ/saɪ, English jay/sigh) are subatomic particles made of one charm quark and one charm antiquark. Mesons are a family of composite particles which are made of one quark and one antiquark. It was discovered by Burton Richter.
Who discovered the J psi particle?
Burton Richter
J/psi meson
| Composition | c c |
|---|---|
| Discovered | SLAC: Burton Richter et al. (1974) BNL: Samuel Ting et al. (1974) |
| Types | 1 |
| Mass | 5.5208×10−27 kg 3.096916 GeV/c2 |
| Decays into | 3 g or γ +2 g or γ |
How was the J PSI discovered?
On November 10, 1974, SLAC’s Burton Richter and colleagues found evidence for a particle they called the Ψ (the Greek letter Psi). Both were the same particle and papers from both groups were published in Physical Review Letters on 2 December, 1974, as the first evidence for what is now known as the J/Ψ.
Why are free quarks not observed?
A free quark is not observed because by the time the separation is on an observable scale, the energy is far above the pair production energy for quark-antiquark pairs. For the U and D quarks the masses are 10s of MeV so pair production would occur for distances much less than a fermi.
What is the mass of a muon?
| muon mass | |
|---|---|
| Numerical value | 1.883 531 627 x 10-28 kg |
| Standard uncertainty | 0.000 000 042 x 10-28 kg |
| Relative standard uncertainty | 2.2 x 10-8 |
| Concise form | 1.883 531 627(42) x 10-28 kg |
What particle has 3.1 GeV mass?
J/psi particle, type of meson consisting of a charmed quark and a charmed antiquark. It has a mass of 3.1 GeV/c2, which is about 3.5 times larger than the mass of a proton.
Can a single quark exist on its own?
Other particles — electrons, neutrinos, photons and more — can exist on their own. But quarks never will.
Is a muon like an electron?
muon, elementary subatomic particle similar to the electron but 207 times heavier. It has two forms, the negatively charged muon and its positively charged antiparticle. The muon was discovered as a constituent of cosmic-ray particle “showers” in 1936 by the American physicists Carl D.
Where do muons exist?
Muon sources About 10,000 muons reach every square meter of the earth’s surface a minute; these charged particles form as by-products of cosmic rays colliding with molecules in the upper atmosphere.
How many baryons exist?
Baryons need 3 quarks to maintain color neutrality (1 red, 1 blue, 1 green) and with 6 types of quarks, that’s 216 possible combinations, but the top quark doesn’t form any baryons, so that leaves 75 possible Baryons – which is the number listed in the list of Baryons.
Can you have 3 up quarks?
Yes. Three up quarks form a particle, while three down quarks form a particle.