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A truncated bag model of hadrons

The mode sum in bag model field operators is truncated for the purpose of studying higher order effects of QCD in a cavity. A perturbation theory method is developed in order to calculate higher order effects in a noncovariant way, as is necessitated by the noncovariant nature of the static cavity approximation. O($\alpha\sbsp{\rm s}{2}$) energy shifts are calculated for the ground state hadrons and bag model parameters are determined by a fit to hadron masses. The quark self-energy due just to the quark-gluon interaction is determined to O($\alpha\sbsp{\rm s}{6}$) using a pattern recognition code which finds and calculates over 10,000 diagrams. This same quark self-energy is summed to all orders in the planar approximation. The O($\alpha\sbsp{\rm s}{2}$) energy shifts of the H dibaryon and several diquark systems are also calculated by using a pattern recognition code. We find that the diquark state which is most bound at O($\alpha\sb{\rm s}$) remains so at O($\alpha\sbsp{\rm s}{2}$). We find the mass of the H dibaryon to be 2.1 $\pm$ 0.1 GeV. O($\alpha\sbsp{\rm s}{2}$) energy shifts for the J$\sp{\rm PC}$ = 0$\sp{++}$ glueball are calculated. This glueball is found to have negative mass at O($\alpha\sb{\rm s}$), but the O($\alpha\sbsp{\rm s}{2}$) shift nearly cancels the O($\alpha\sb{\rm s}$) shift leading to a glueball mass of approximately 1.2 GeV. Problems regarding independent particle wave functions and the Coulomb interaction are also discussed.

Identiferoai:union.ndltd.org:UMASS/oai:scholarworks.umass.edu:dissertations-8220
Date01 January 1991
CreatorsSotirelis, Thomas Sotirios
PublisherScholarWorks@UMass Amherst
Source SetsUniversity of Massachusetts, Amherst
LanguageEnglish
Detected LanguageEnglish
Typetext
SourceDoctoral Dissertations Available from Proquest

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