PROGRAM SUMMARY
Title of program:
BSE
Catalogue identifier:
ADPT
Ref. in CPC:
144(2002)63
Distribution format: gzip file
Operating system: True-Unixv5.0, SuSe Linux 7.1
High speed store required:
10MK words
Number of bits in a word:
32
Peripherals Required: disc
Number of lines in distributed program, including test data, etc:
943
Keywords:
Linear integral equations, Bethe-Salpeter equation, Nucleon model,
Diquarks, Elementary particle physics, Phenomenological model.
Programming language used: Fortran
Computer:
Workstation DEC Aplha ,
LINUX PCs (AMD K7) .
Nature of physical problem:
Diquarks are introduced as separable correlations in the two-quark
Green's function to facilitate the description of baryons as
relativistic three-quark bound states. These states then emerge as
solutions of Bethe-Salpeter equations for quarks and diquarks that
interact via quark exchange.
Method of solution:
Chebyshev polynomials are used for an expansion of the Bethe-Salpeter
vertex and wave functions and an (approximative) representation of the
interaction kernel and propagators. The resulting set of coupled
one-dimensional integral equations for the corresponding moments of
vertex and wave function is converted to a matrix equation by employing
Gaussian quadrature grid points. This equation is then solved
iteratively for a certain test mass of the bound state. A bisection
method in the bound state mass variable is used to determine the correct
mass corresponding to the chosen quark and diquark parameters.
Restrictions:
The separable quark-quark correlations are restricted to the leading
covariants in the scalar and axialvector (i.e. positive parity)
channels.
Typical running time:
Depending on the parameters and the desired accuracy between one and ten
minutes on 1.2 GHz AMD K7.
Additional comments:
Programming issue The program has been tested with the following
compilers: DEC-f90v5.3, Lahey-Fujitsu-f95-LINUX-Expressv5.5,
NagWare-f95.