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Variational quantum-field-theoretical approach to the chiral bag
Phys. Rev. D 32, 2396 – Published 1 November, 1985
DOI: https://doi.org/10.1103/PhysRevD.32.2396
Abstract
A variational quantum-field-theoretical approach to the chiral bag is presented in which the pion field is described by a quantum-mechanical coherent state coupled to the bag by the interaction Hamiltonian of the linearized cloudy-bag model. States with good spin and isospin quantum numbers are projected from variationally stable solutions. Techniques are explained in detail. The nucleon is stabilized against collapse by incorporating the finite extension of the pions in the field. The dependence of nucleon masses, bag radii, average pion numbers, and self-energies on the various parameters is investigated. The free parameters of the system are fixed by requiring the variational solutions to have the proper nucleon energy and the proper pion-nucleon vertex. Bag radii of ∼0.5 fm are obtained for certain parameter sets if Δ degrees of freedom are considered in the bag’s wave function. For this and other features quantum fluctuations are shown to be important.
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