|Institution:||University of Minnesota|
|Keywords:||Heavy flavor thresholds; Hadroquarkonium; Charmonium; Physics|
|Full text PDF:||http://purl.umn.edu/56652|
Some properties of the old and new states of quarkonium as well as QCD based methods for studying those states are discussed. A general formula for observable effects of isospin violation in the production of heavy mesons in e + e - annihilation is derived in Chapter 2. In addition the production and scattering amplitudes of heavy mesons with the presence of two closely spaced narrow resonances are studied. In Chapter 3 an alternative viable source of the X (3872) resonance with simple kinematics is suggested. Further, the transitions from resonance X (3872) to the χ cJ states of charmonium with emission of one or two pions are considered. It is found that the relative rates for these transitions to final states with different J may shed light on the understanding of isotopic structure of the X (3872) and the prominence of the four-quark component in it's internal dynamics. Chapter 4 is devoted to study of new J PC = 1 – resonances. It is argued that relatively compact charmonium states, J /ψ, ψ(2 S ), χ c , can very likely be bound inside light hadronic matter, in particular inside higher resonances made from light quarks and/or gluons. The charmonium state in such binding essentially retains its properties, so that the bound system decays into light mesons and a particular charmonium resonance. Such bound states of a new type, hadro-charmonium, may explain the properties of some of the recently observed resonant peaks, in particular of Y (4.26), Y (4.32 - 4.36), Y (4.66), and Z (4.43). Further possible implications of the suggested picture for the observed states and existence of other states of hadro-charmonium and hadro-bottomonium are discussed. In Chapter 5 it is argued that the existing analysis of the experimental data on the dipion transition Υ(3 S ) [arrow right] Υ(1 S ) ππ was incomplete and suggestions to remove the internal ambiguity are made.