Upsilon meson

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Upsilon (
ϒ
)
Upsilon peak.jpg
A plot of the invariant mass of muon pairs, from the Upsilon particle discovery paper. The peak at about 9.5 GeV is due to the contribution of the Upsilon meson.
Composition
b

b
Statistics Bosonic
Symbol
ϒ
Antiparticle Self
Discovered E288 experiment
Mass 9.46030(26) GeV/c2
Electric charge 0 e
Spin 1

The Upsilon meson (
ϒ
) is a quarkonium state (i.e. flavourless meson) formed from a bottom quark and its antiparticle. It was discovered by the E288 experiment team, headed by Leon Lederman, at Fermilab 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 1.21×10−20 s and a mass about 9.46 GeV/c2 in the ground state.

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