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A truncated bag model of hadrons
Abstract
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.
Subject Area
Particle physics
Recommended Citation
Sotirelis, Thomas Sotirios, "A truncated bag model of hadrons" (1991). Doctoral Dissertations Available from Proquest. AAI9207460.
https://scholarworks.umass.edu/dissertations/AAI9207460