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meson

(Encyclopedia)meson mēˈzŏn [key] [Gr.,=middle (i.e., middleweight)], class of elementary particles whose masses are generally between those of the lepton class of lighter particles and those of the baryon class ...

elementary particles

(Encyclopedia)CE5 elementary particles, the most basic physical constituents of the universe. The first subatomic particle to be discovered was the electron, identified in 1897 by J. J. Thomson. After the...

antiparticle

(Encyclopedia)antiparticle, elementary particle corresponding to an ordinary particle such as the proton, neutron, or electron, but having the opposite electrical charge and magnetic moment. Every elementary partic...

transmutation of elements

(Encyclopedia)transmutation of elements, conversion of one chemical element into another. The expression has both historical and contemporary significance. The transmutation of certain metals into gold by means of ...

polonium

(Encyclopedia)polonium pəlōˈnēəm [key], radioactive chemical element; symbol Po; at. no. 84; mass no. of most stable isotope 209; m.p. 254℃; b.p. 962℃; sp. gr. about 9.4; valence +2 or +4. Polonium is an e...

cosmic rays

(Encyclopedia)cosmic rays, charged particles moving at nearly the speed of light reaching the earth from outer space. Primary cosmic rays consist mostly of protons (nuclei of hydrogen atoms), some alpha particles (...

tunneling

(Encyclopedia)tunneling, quantum-mechanical effect by which a particle can penetrate a barrier into a region of space that would be forbidden by ordinary classical mechanics. Tunneling is a direct result of the wav...

Fermilab

(Encyclopedia)Fermilab: see Fermi National Accelerator Laboratory. ...

Higgs boson, Higgs field, and Higgs particle

(Encyclopedia)Higgs boson, Higgs field, and Higgs particle: see elementary particles. ...

Charpak, Georges

(Encyclopedia)Charpak, Georges zhôrzh shärpäkˈ [key], 1924–2010, French physicist, b. Dąbrowica, Poland (now Dubrovytsia, Ukraine), Ph.D Collège de France, 1954. Affiliated with CERN (1959–91), Charpak wo...