J/psi particle

English J/ψ meson thumb|This image shows that a positive pion (π+) is made up of two tiny particles; an up quark (left) and an anti-down quark (right). Alternative forms en J/ψ meson en J/psi meson en J/ψ particle en J particle en psion obsolete Etymology A compound of en J, grc ψ (psi), and en particle. The particle was discovered independently in 1974 by two research groups, leading to the "November Revolution" in particle physics. The group led by Samuel Ting at Brookhaven National Laboratory proposed the name J, reputedly because the shape of the Chinese character for Ting (zh 丁) resembles a J, though Ting also cited the symbol for electromagnetic current, , as a reason.https://www.nobelprize.org/uploads/2018/06/ting-lecture.pdf The Discovery of the J Particle Samuel Ting Nobel Prize Lecture 1976-12-11 2025-12-16 https://web.archive.org/web/20260609151648/https://www.nobelprize.org/uploads/2018/06/ting-lecture.pdf 9 June 2026 The group led by Burton Richter at SLAC proposed the name ψ (psi). Richter initially preferred "SP" (for the SPEAR accelerator), but chose "psi" as it contained "SP" in reverse order and was the only remaining Greek letter deemed suitable; coincidently, the particle's decay pattern in spark chambers resembled the letter ψ. The compromise name J/ψ was adopted to acknowledge both discoveries. Pronunciation en /ˌdʒeɪ ˈsaɪ ˈpɑːtɪkl̩/ UK en /ˌdʒeɪ ˈsaɪ ˈpɑɹtɪkəl/ /ˌdʒeɪ ˈpsaɪ ˈpɑɹtɪkəl/ US en J ψ par ti cle en ɑː(ɹ)tɪkəl Noun J/ψ particle en particle physics A subatomic particle with an unusually long lifetime (7.2 × 10−21 s) and a large mass (approx. 3.097 GeV/c²); a bound state of a charm quark and an anti-charm quark (the most common form of charmonium). en J/psi meson psion en 1974 J. J. Aubert et al. Experimental Observation of a Heavy Particle J Physical Review Letters 33 23 1404–1406 10.1103/PhysRevLett.33.1404 We report the observation of a heavy particle J, with mass m = 3.1 GeV and width approximately zero. en 1974 J. E. Augustin et al. Discovery of a Narrow Resonance in e+e- Annihilation Physical Review Letters 33 23 1406–1408 10.1103/PhysRevLett.33.1406 We denote this resonance as ψ(3105). Hypernyms en boson charmonium hadron meson quarkonium vector meson Translations subatomic particle Chinese: Mandarin: cmn J/ψ介子 J/ψ jièzǐ French: fr méson J/ψ m German: de J/ψ-Meson n Italian: it mesone J/ψ m Japanese: ja ジェイプサイ中間子 ジェイプサイちゅうかんし, Jeipusai chūkanshi Russian: ru J/ψ-мезон m Spanish: es mesón J/ψ m References Further reading J/psi particle en Subatomic particles Physics Matter