- Tetraquark
In
particle physics a tetraquark is a hypotheticalmeson composed of four valencequarks . In principle, a tetraquark state may be allowed inQuantum chromodynamics , the modern theory ofstrong interactions . However, there has been no confirmed report of a tetraquark state to date. Any established tetraquark state would be an example of anexotic hadron which lies outside thequark model classification.In 2003 a particle temporarily called "
X(3872) ", by theBelle experiment inJapan , was suggested as a tetraquark candidate. The name "X" is a temporary name, indicating that there are still some questions about its properties to be tested. The number following is the mass of the particle inMeV .In 2004 the DsJ(2632) state, seen in the SELEX experiment, was suggested as a possible tetraquark candidate.
ee also
*
Pentaquark
*Quark model
*Hadron ,exotic hadron
*Quantum chromodynamics ,color confinement References and external links
* [http://belle.kek.jp The Belle experiment]
** [http://www.kek.jp/press/2003/belle4e.html Belle press release]
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