Charm quark

Charm quark
Composition Elementary particle
Statistics Fermionic
Generation Second
Interactions Strong, Weak, Electromagnetic force, Gravity
Symbol c
Antiparticle Charm antiquark (c)
Theorized Sheldon Glashow,
John Iliopoulos,
Luciano Maiani (1970)
Discovered Burton Richter et al. (SLAC)
(1974)
Samuel Ting et al. (BNL)
(1974)
Mass 1.29+0.05
−0.11
 GeV/c2
[1]
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 (J/ψ), D mesons (D), charmed Sigma baryons (Σ
c
), 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
−0.11
 GeV/c2
.[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 J/ψ (and thus the charm quark) ushered in a series of breakthroughs which are collectively known as the November Revolution.

Contents

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.
  • D
    s
    mesons contain a charm quark and a strange quark.
  • There are many charmonium states, for example the J/ψ 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. Λ+
    c
    ).

See also

Notes

  1. ^ a b K. Nakamura et al. (Particle Data Group) (2011). "PDGLive Particle Summary 'Quarks (u, d, s, c, b, t, b', t', Free)'". Particle Data Group. http://pdg.lbl.gov/2011/tables/rpp2011-sum-quarks.pdf. Retrieved 2011-08-08. 
  2. ^ Carl Rod Nave. "Transformation of Quark Flavors by the Weak Interaction". http://hyperphysics.phy-astr.gsu.edu/hbase/particles/qrkdec.html. Retrieved 2010-12-06. "The c quark has about 5% probability of decaying into a d quark instead of an s quark." 
  3. ^ K. Nakamura et al. (2010). "Review of Particles Physics: The CKM Quark-Mixing Matrix". J. Phys. G 37 (75021): 150. http://pdg.lbl.gov/2010/reviews/rpp2010-rev-ckm-matrix.pdf. 
  4. ^ B.J. Bjorken, S.L. Glashow (1964). "Elementary particles and SU(4)". Physics Letters 11 (3): 255–257. Bibcode 1964PhL....11..255B. doi:10.1016/0031-9163(64)90433-0. 
  5. ^ S.L. Glashow, J. Iliopoulos, L. Maiani (1970). "Weak Interactions with Lepton–Hadron Symmetry". Physical Review D 2 (7): 1285–1292. Bibcode 1970PhRvD...2.1285G. doi:10.1103/PhysRevD.2.1285. 
  6. ^ J.-E. Augustin et al. (1974). "Discovery of a Narrow Resonance in e+e Annihilation". Physical Review Letters 33 (23): 1406. Bibcode 1974PhRvL..33.1406A. doi:10.1103/PhysRevLett.33.1406. 
  7. ^ J.J. Aubert et al. (1974). "Experimental Observation of a Heavy Particle J". Physical Review Letters 33 (23): 1404. Bibcode 1974PhRvL..33.1404A. doi:10.1103/PhysRevLett.33.1404. 

Further reading



Wikimedia Foundation. 2010.

Look at other dictionaries:

  • charm quark — n. Particle Physics CHARMED QUARK * * * …   Universalium

  • charm quark — n. Particle Physics CHARMED QUARK …   English World dictionary

  • Charm-Quark — Ein Proton, bestehend aus zwei up Quarks und einem down Quark Quarks (kwɔrk, kwɑːk oder kwɑːrk) sind die elementaren Bestandteile (Elementarteilchen), aus denen man sich …   Deutsch Wikipedia

  • Charm Quark — Ein Proton, bestehend aus zwei up Quarks und einem down Quark Quarks (kwɔrk, kwɑːk oder kwɑːrk) sind die elementaren Bestandteile (Elementarteilchen), aus denen man sich …   Deutsch Wikipedia

  • Charm-Quark — žavusis kvarkas statusas T sritis fizika atitikmenys: angl. charm quark; charmed quark vok. Charm Quark, n rus. очарованный кварк, m pranc. quark charme, m …   Fizikos terminų žodynas

  • charm quark — žavusis kvarkas statusas T sritis fizika atitikmenys: angl. charm quark; charmed quark vok. Charm Quark, n rus. очарованный кварк, m pranc. quark charme, m …   Fizikos terminų žodynas

  • charm quark — noun a quark with an electric charge of +2/3 and a mass 2900 times that of an electron and a charm of +1 • Hypernyms: ↑quark …   Useful english dictionary

  • charm quark — noun A quark having a fractional electric charge of +2/3 and a mass about 1150 to 1350 MeV. Symbol: c …   Wiktionary

  • Anti-Charm-Quark — Ein Proton, bestehend aus zwei up Quarks und einem down Quark Quarks (kwɔrk, kwɑːk oder kwɑːrk) sind die elementaren Bestandteile (Elementarteilchen), aus denen man sich …   Deutsch Wikipedia

  • anti-charm quark — noun the antiquark corresponding to the charm quark …   Wiktionary


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.