upsilon
(juːpˈsaɪlən, ˈʊpsɪlɒn)
[a. Gr. ὖ ψιλόν ‘slender u’, the adj. having reference to its later sound (y).]
1. The Greek letter υ, υ (originally V, Y) representing the vowel u (see U, V, and Y). Also attrib., = having the form of this letter.
| 1642 Howell For. Trav. xi. (Arb.) 56 In some places of the Morea..they confound these three leters η, ι, υ (Eta, Iota, Upsilon). 1693 Dryden Persius, Sat. iii. 109 note, Pithagoras of Samos made the allusion of the Y, or Greek Upsilon, to Vice and Virtue. 1763 Ann. Reg., Misc. 194/1 The last notes..(pronounced as the Greek upsilon, or the French u). 1799 Townson Tracts & Observ. Nat. Hist. 75 The upsilon Cartilage. 1820 T. S. Hughes Trav. Sicily I. 245 The only people who pronounce the letter upsilon like the Italian u. 1854 Bushnan in Orr's Circ. Sci., Org. Nat. I. 121 The hyoid bone is described as having the shape of the Greek upsilon. |
2. Ent. A species of moth (see quot.).
| 1832 Rennie Brit. Butterfl. & M. 59 The Upsilon (Orthosia Upsilon, Ochsenheimer) appears in July,..the stigmata pale, between which is a black mark resembling a Y or V. |
3. Particle Physics. A meson with a mass of about 9·4 GeV that is thought to consist of a b quark and its antiquark; also upsilon particle. Freq. designated by υ.
| [1976 Daily Tel. 7 Feb. 10/4 Upsilon was discovered by a team of scientists from Columbia University, New York, the Fermi Laboratory and the State University of New York. 1976 D. C. Hom et al. in Physical Rev. Lett. 24 May 1239/2 We suggest the name υ (upsilon) be given either to the resonance at 6 GeV if confirmed or to the onset of high-mass dilepton physics.] 1977 S. W. Herb et al. in Ibid. 1 Aug. 255/2 Following ref. 1 [sc. prec. quot.], a reasonable designation for this enhancement is υ(9·5). 1979 Nature 7 June 482/2 The more recently discovered upsilon T [? read υ]..should provide an even better system for investigating QCD effects as the coupling strength for that very massive quark system is even smaller. 1980 TWA Ambassador Oct. 61/3 Dr. Charles had told me about Truth and Beauty—that is, the quarks given those names—and the discovery in 1977 of the upsilon particle, which seems to be a meson consisting of a beauty quark and a beauty antiquark. |
Hence upˈsilonism, tendency to use the letter u.
| 1879 T. F. Simmons Lay Folks Mass Bk. Introd. p. lvi, The perpetual upsilonism of our West-Midland text E. |