subatomic
111fermion — /ferr mee on /, n. Physics. any particle that obeys the exclusion principle and Fermi Dirac statistics; fermions have spins that are half an odd integer: 1/2, 3/2, 5/2, . ... [1945 50; FERMI + (MES)ON] * * * Any of a group of subatomic particles… …
112lepton — lepton1 /lep ton/, n., pl. lepta / teuh/. 1. an aluminum coin of modern Greece, the 100th part of a drachma. 2. a small copper or bronze coin of ancient Greece. [1715 25; < Gk leptón (nómisma) a small (coin), n. use of neut. of leptós small; see… …
113muon — muonic, adj. /myooh on/, n. Physics. a lepton similar in most respects to the electron except that it is unstable, it may be positively charged, and its mass is approximately 207 times greater; the positively charged muon is the antiparticle of… …
114parity — parity1 /par i tee/, n. 1. equality, as in amount, status, or character. 2. equivalence; correspondence; similarity; analogy. 3. Finance. a. equivalence in value in the currency of another country. b. equivalence in value at a fixed ratio between …
115positron — /poz i tron /, n. Physics. an elementary particle having the same mass and spin as an electron but having a positive charge equal in magnitude to that of the electron s negative charge; the antiparticle of the electron. Also called antielectron,… …
116quantum electrodynamics — Physics. the quantum field theory that deals with the electromagnetic field and its interaction with electrons and positrons. Abbr.: QED [1925 30] * * * ▪ physics quantum field theory of the interactions of charged (electric charge)… …
117string theory — Physics. See under string (def. 3). * * * ▪ physics Introduction in particle physics, a theory that attempts to merge quantum mechanics with Albert Einstein (Einstein, Albert) s general theory of relativity (relativity). The name string… …
118strong force — Physics. 1. the short range attractive force between baryons that holds together the nucleus of the atom. 2. Also called color force. the force between quarks. Cf. gluon, strong interaction. [1965 70] * * * or strong nuclear force Fundamental… …
119supersymmetry — /sooh peuhr sim i tree/, n. Physics. a hypothetical symmetry among groups of particles containing fermions and bosons, esp. in theories of gravity (supergravity) that unify electromagnetism, the weak force, and the strong force with gravity into… …
120symmetry — /sim i tree/, n., pl. symmetries. 1. the correspondence in size, form, and arrangement of parts on opposite sides of a plane, line, or point; regularity of form or arrangement in terms of like, reciprocal, or corresponding parts. 2. the proper or …
