Programs in Physics & Physical Chemistry
|[Licence| Download | New Version Template] aavq_v1_0.gz(6 Kbytes)|
|Manuscript Title: Soliton bag model.|
|Authors: R. Saly|
|Program title: SOLITON|
|Catalogue identifier: AAVQ_v1_0|
Distribution format: gz
|Journal reference: Comput. Phys. Commun. 30(1983)411|
|Programming language: Fortran.|
|Operating system: VAX/VMS.|
|RAM: 40K words|
|Word size: 32|
|Keywords: Elementary, Particle physics, Empirical model, Nonlinear differential Equations, Soliton, Bag model, Dirac equation.|
Nature of problem:
The soliton bag model is a generalization of the MIT and SLAC bag models. Mathematically the problem equals to boundary and eigenvalue problems for a system of coupled linear ordinary differential equations, integral equations and a nonlinear differential equation. The calculated quantities include: quark energy, bag energy, total hadron energy, magnetic moment, charge radius, ratio of axial-vector/ vector coupling, etc.
The problem is solved by iteration whose cycle involves the following three steps:
1) solution of the radial Dirac equations (eigenvalue problem),
2) renormalization of the quark wave functions,
3) solution of the nonlinear differential equation by the Newton method (two point boundary value problem).
The main tool in all three steps is a direct Taylor series expansion of the functions involved. The boundary (eigenvalue) problems are solved using a shooting method based on bi-section and parabola iteration.
Execution of the program in the test case (accuracy 0.5% or 12 iterations) takes 1 min on the VAX-11 computer.
|Disclaimer | ScienceDirect | CPC Journal | CPC | QUB|