upsilon meson

subatomic particle

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July 14, 2026

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The upsilon is a type of meson, which is a subatomic particle composed of a quark and an antiquark. Mesons are sensitive to the strong force that binds quarks together. The upsilon particle has a mass approximately 10 times that of a proton and is electrically neutral. Its discovery, along with the J/psi particle, provided evidence for the existence of heavier quarks, such as the bottom quark. These discoveries were crucial in developing the Standard Model of particle physics.1234

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meson
…of another heavy meson, called upsilon, revealed the existence of the bottom quark and its accompanying antiquark and gave rise to speculation about the existence of a companion particle, the top quark. This sixth quark type, or “flavour,” was discovered in 1995. Conclusive proof of its existence culminated the search…
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…of another heavy meson, called upsilon, revealed the existence of the bottom quark and its accompanying antiquark and gave rise to speculation about the existence of a companion particle, the top quark. This sixth quark type, or “flavour,” was discovered in 1995. Conclusive proof of its existence culminated the search…
Read More

Fermi National Accelerator Laboratory
…the first evidence for the upsilon meson, which revealed the existence of the bottom quark. The bottom quark, the fifth quark to be detected, is a member of the third and heaviest pair of quarks. The companion particle of this pair is the top quark, which is the sixth and…
Read More
…the first evidence for the upsilon meson, which revealed the existence of the bottom quark. The bottom quark, the fifth quark to be detected, is a member of the third and heaviest pair of quarks. The companion particle of this pair is the top quark, which is the sixth and…
Read More