Meanings
plural J/psi particles · alternative J/ψ meson · alternative J/psi meson · alternative J/ψ particle · alternative J particle · alternative psion
- particlenatural sciencesA 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).
We denote this resonance as ψ(3105).
1974, J. E. Augustin et al., “Discovery of a Narrow Resonance in e⁺e⁻ Annihilation”, in Physical Review Letters, volume 33, number 23, →DOI, pages 1406–14081 more example
We report the observation of a heavy particle J, with mass m = 3.1 GeV and width approximately zero.
1974, J. J. Aubert et al., “Experimental Observation of a Heavy Particle J”, in Physical Review Letters, volume 33, number 23, →DOI, pages 1404–1406Synonyms: J/psi meson, psion
Synonyms & antonyms
nounA 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).
Origin
A compound of J, ψ (ps) (psi), and 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 (丁) resembles a J, though Ting also cited the symbol for electromagnetic current, j_μ(x), as a reason. * 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.
Full word history & related roots →Translations
Chinese Mandarin J, ψ介子
- J (J/ψ jièzǐ)subatomic particle
- ψ介子 (J/ψ jièzǐ)subatomic particle
French méson J/ψ
- méson J/ψsubatomic particle
German J, ψ-Meson
- Jsubatomic particle
- ψ-Mesonsubatomic particle
Italian mesone J/ψ
- mesone J/ψsubatomic particle
Japanese ジェイプサイ中間子
- ジェイプサイ中間子 (Jeipusai chūkanshi)subatomic particle
Russian J, ψ-мезон
- J (J/ψ-mezon)subatomic particle
- ψ-мезон (J/ψ-mezon)subatomic particle
Spanish mesón J/ψ
- mesón J/ψsubatomic particle
Rhymes & wordplay
Rhymes with J/psi particle
All rhymes →Cite this entry
J/psi particle. (n.d.). In WatkinsX Dictionary. Retrieved November 5, 2026, from https://dictionary.watkinsx.com/word/J%2Fpsi%20particle
“J/psi particle.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/J%2Fpsi%20particle. Accessed November 5, 2026.
WatkinsX Dictionary, s.v. “J/psi particle,” accessed November 5, 2026, https://dictionary.watkinsx.com/word/J%2Fpsi%20particle.
Source: J/psi particle on Wiktionary, CC BY-SA 4.0.