The Upsilon meson () is a
quarkonium state (i.e.
flavourless meson
In particle physics, a meson ( or ) is a type of hadronic subatomic particle composed of an equal number of quarks and antiquarks, usually one of each, bound together by the strong interaction. Because mesons are composed of quark subparticles, ...
) formed from a
bottom quark
The bottom quark or b quark, also known as the beauty quark, is a third-generation heavy quark with a charge of − ''e''.
All quarks are described in a similar way by electroweak and quantum chromodynamics, but the bottom quark has exce ...
and its
antiparticle
In particle physics, every type of particle is associated with an antiparticle with the same mass but with opposite physical charges (such as electric charge). For example, the antiparticle of the electron is the positron (also known as an antie ...
. It was discovered by the
E288 experiment
E, or e, is the fifth letter and the second vowel letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''e'' (pronounced ); plur ...
team, headed by
Leon Lederman, at
Fermilab
Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a United States Department of Energy national laboratory specializing in high-energy particle physics. Since 2007, Fermilab has been opera ...
in 1977, and was the first particle containing a bottom quark to be discovered because it is the lightest that can be produced without additional massive particles. It has a
lifetime of and a mass about in the ground state.
See also
*
Oops-Leon, an erroneously-claimed discovery of a similar particle at a lower mass in 1976.
* The particle is the analogous state made from
strange quarks.
* The particle is the analogous state made from
charm quark
The charm quark, charmed 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. Examples of hadrons containin ...
s.
*
List of mesons
:''This list is of all known and predicted scalar, pseudoscalar and vector mesons. See list of particles for a more detailed list of particles found in particle physics.''
This article contains a list of mesons, unstable subatomic particles ...
References
*
*
*
Mesons
Onia
Subatomic particles with spin 1
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