The T family and its experimental status

No further narrow vector resonances were discovered in the mass range 4.5 GeV/c /i 9.5GeV/c, but a few years after the discovery of the 

a narrow resonance was found as an enhancement in the dimuon mass spectrum in proton-nucleus collisions at 400 GeV/c at Fermilab in the reactions 

The new resonance (Herb et al., 1977 Ledermann, 1978) at a mass of 9.46 GeV/c was named T(9.46). Its rich spectroscopy had actually been anticipated (Eichten and GottMed, 1976) on the basis of the theoretical scheme discussed in the next Chapter. 

Remarkably, the T was then confirmed by the e e machine CESR at Cornell University. The remarkably clear resolution of the peaks is shown in Fig. 11.20. 

The very rich spectroscopy unveiled mainly at Cornell and SLAC is summarized in Table 11.6. Much the same kind of analysis as for the J/ family applies here mutatis mutandis. 

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