The spectrum of mesons
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The spectrum of mesons |
In 1983 I gave a talk on the VI Warsaw symposium on elementary particle physics (Kazimierz, Poland, May 29 - June 4, 1983) in which I discussed the spectrum of mesons. In particular, I discussed an important property of confinement, namely, that the level spacings for mesons of different flavor combinations are all to a large extend equal. Small deviations from that pattern, which may be more than 100 MeV for some classes of states, and even several hundreds of MeV for some of the ground states, are due to interactions different from confinement, mainly dominated by the creation of quarks and antiquarks. Furthermore, I showed that the level spacings of the spectrum of mesons are constant, and of the order of 380 MeV, which coincides with the spectrum of a harmonic oscillator or of Anti-De Sitter confinement. The former option is mathematically easier for confinement models, whereas, moreover, it allows for a fairly easy incorporation of the effects of quark-pair creation. The latter could just be handled by one overall parameter. The figure shows how this works out for the spectrum of charmonium. |