Charm antiquark

Charm quark
Composition Elementary particle
Statistics Fermionic
Generation Second
Interactions Strong, Weak, Electromagnetic force, Gravity
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Charm antiquark (

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Theorized Sheldon Glashow,
John Iliopoulos,
Luciano Maiani (1970)
Discovered Burton Richter et al. (SLAC)
Samuel Ting et al. (BNL)
Mass 1.29+0.05
Decays into Strange quark (~95%), Down quark (~5%)[2][3]
Electric charge +23 e
Color charge Yes
Spin 12
Weak isospin LH: +12, RH: 0
Weak hypercharge LH: +13, RH: +43

The charm quark or c quark (from its symbol, c) is the third most massive of all quarks, a type of elementary particle. Charm quarks are found in hadrons, which are subatomic particles made of quarks. Example of hadrons containing charm quarks include the J/ψ meson (

  1. redirect ), D mesons (
  2. redirect ), charmed Sigma baryons (
  3. redirect ), and other charmed particles.

It, along with the strange quark is part of the second generation of matter, and has an electric charge of +23 e and a bare mass of 1.29+0.05
.[1] Like all quarks, the charm quark is an elementary fermion with spin-12, and experiences all four fundamental interactions: gravitation, electromagnetism, weak interactions, and strong interactions. The antiparticle of the charm quark is the charm antiquark (sometimes called anticharm quark or simply anticharm), which differs from it only in that some of its properties have equal magnitude but opposite sign.

The existence of a fourth quark had been speculated by a number of authors around 1964 (for instance by James Bjorken and Sheldon Glashow[4]), but its prediction is usually credited to Sheldon Glashow, John Iliopoulos and Luciano Maiani in 1970 (see GIM mechanism).[5] The first charmed particle (a particle containing a charm quark) to be discovered was the J/ψ meson. It was discovered by a team at the Stanford Linear Accelerator Center (SLAC), led by Burton Richter,[6] and one at the Brookhaven National Laboratory (BNL), led by Samuel Ting.[7]

The 1974 discovery of the

  1. redirect (and thus the charm quark) ushered in a series of breakthroughs which are collectively known as the November Revolution.

Hadrons containing charm quarks

Main articles: List of baryons and list of mesons

Some of the hadrons containing charm quarks include:

  1. redirect mesons contain a charm quark and a strange quark.
  • There are many charmonium states, for example the
  1. redirect particle. These consist of a charm quark and its antiparticle.
  • Charmed baryons have been observed, and are named in analogy with strange baryons (e.g.
  1. redirect ).

See also


Further reading