= Richter-Ting independent J/psi discovery experiments
{c}
In 1974, <Samuel Chao Chung Ting>'s Brookhaven team and <Burton Richter>'s SPEAR team independently found the narrow state now called the <J psi meson>. Each discovery paper notes learning of the other result during manuscript preparation.<Experimental Observation of a Heavy Particle J by J. J. Aubert>[Aubert and others, p. 1406, note 5: independent SPEAR result]{ref}<Discovery of a Narrow Resonance in e+e- Annihilation by J.-E. Augustin>[Augustin and others, p. 1408, note 3: independent Brookhaven result]{ref}
\Image[/j-psi-fixed-target-and-collider-geometry.png]
{title=Fixed-target pair reconstruction and a storage-ring energy scan}
{description=Original functional schematics; dimensions, detector positions and outgoing tracks are illustrative.}
The common question was whether the observed excess represented a new <particle resonance>, rather than a peculiarity of <particle identification>, acceptance or calibration. The important difference was the horizontal coordinate of the search: \b[Brookhaven reconstructed a final-state <invariant mass>; SPEAR scanned an initial-state <center-of-mass energy>.] The <invariant-mass selection of bubble-chamber events> uses the first kind of reasoning, despite a very different recording medium.
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