PROGRAM SUMMARY
Title of program:
NEXTCALIBUR
Catalogue identifier:
ADNS
Ref. in CPC:
136(2001)148
Distribution format: tar gzip file
Operating system: UNIX
High speed store required:
500K words
Number of bits in a word:
32
Number of lines in distributed program, including test data, etc:
11133
Keywords:
Elementary particle physics, QCD, Decaying vector-boson production,
All massive four- fermion processes, Electroweak background,
Initial state pt dependent QED radiation, Recursive Dyson-
Schwinger equations, Multi-channel Monte Carlo approach.
Programming language used: Fortran
Computer:
DIGITAL-ALPHA ,
HP .
Nature of problem:
Four-fermion production is and will be investigated at e+e- colliders in
a wide range of energies. Fermion masses have to be included when
studying Higgs boson production and processes with forward scattered
electrons. A Monte Carlo program being able to take into account both
signal and background electroweak diagrams for four-fermion processes,
without neglecting fermion masses, is therefore required. Higher order
effects, such as the QED radiation evaluated at the proper scale, have
also to be included, together with the possibility of generating photons
with a non vanishng pt spectrum. For t-channel dominated processes, the
correct running of alphaEM must be implemented.
Method of solution:
An event generator is the most suitable choice for a program to be able
to deal with the above physical problems. For the matrix element
evaluation, recursive Dyson-Schwinger equations that express the n-point
Green's functions in terms of the 1-, 2-, ..., (n-1)-point functions are
used. The Monte Carlo integration is performed by using an efficient
self-optimizing multi-channel approach.
Typical running time:
About 250 weighted events per second, in double precision on DIGITAL-
ALPHA/21164 DS20 (500MHz), depending on the chosen physical process.
Unusual features:
By changing compilation procedure, the program can run both in double
and quadruple precision.