The Upsilon meson (
) 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.
|Interactions||Strong, weak, Electromagnetic, Gravity|
|Discovered||E288 experiment (1977)|
|Mean lifetime||1.21×10−20 s|
|Electric charge||0 e|
- D.C. Hom; et al. (1977). "Observation of a Dimuon Resonance at 9.5 Gev in 400-GeV Proton-Nucleus Collisions" (PDF). Physical Review Letters. 39: 252–255. Bibcode:1977PhRvL..39..252H. doi:10.1103/PhysRevLett.39.252.
- J. Yoh (1998). "The Discovery of the b Quark at Fermilab in 1977: The Experiment Coordinator's Story" (PDF). AIP Conference Proceedings. 424: 29–42.
- S. Eidelman et al. (Particle Data Group) (2004). "Review of Particle Physics –
meson" (PDF). Physics Letters B. 592: 1. arXiv:astro-ph/0406663. Bibcode:2004PhLB..592....1P. doi:10.1016/j.physletb.2004.06.001.