PROGRAM SUMMARY
Title of program:
EXOTIC
Catalogue identifier:
ADLJ
Ref. in CPC:
126(2000)244
Distribution format: gzip file
Operating system: HPUX, Solaris, VAX/VMS, IRIX, Linux
High speed store required:
2.5MK words
Number of bits in a word:
32
Number of lines in distributed program, including test data, etc:
5508
Keywords:
Particle physics, Elementary, High energy electron
Positron collisions, Heavy fermions, Excited fermions,
Monte Carlo generator, Standard model, Compositeness,
Exotic fermions, Event simulation.
Programming language used: Fortran
Computer:
HP 9000/700 series ,
SUN Ultra Sparc series ,
DEC alpha ,
SGI ,
Pentium .
CPC Program Library subprograms used:
Cat. Id. Title Ref. in CPC ACTU PYTHIA 5.7 AND JETSET 7.4 82(1994)74 ACTA PHOTOS version 2.0 79(1994)291
Nature of physical problem:
Cross section and event generation for e+e- -> FFbar (pair production),
and e+e- -> fbarF (single production) of heavy or excited fermions which
decay into their light standard fermion partner and a gauge boson. The
processes generated account for full spin correlations in the production
and decay processes, with inclusion of initial and final state radiation
(see chapter 3 for details). An interface to JETSET allows
fragmentation and hadronization of final quarks.
Method of solution
For fast Monte Carlo generation of unweighted events, some distributions
are calculated once, then sampled. Event sampling is done only at the
last stage, after evaluation of the total polarized differential cross
section according to its maximum value.
Restrictions on the complexity of the problem
The program is specifically designed for high energy e+e- collisions,
i.e. at LEP 2 and NLC. The program does not include cascade decays,
where a heavy fermion decays into a lighter heavy fermion, which in turn
decays also into a light standard fermion and a gauge boson.
Typical running time
With initial state radiation and full spin correlations, the generation
of 5000 unweighted events e+e- -> FFbar without fragmentation and
hadronization of final quarks takes on average 205 seconds in CPU time
on an HP 9000/755 (275 seconds when including fragmentation and
hadronization).
Unusual features of the program
REAL*8 and COMPLEX*8 declarations are used. For some processes, the
program uses the GENBOD routine, from the CERN program library [4]
(RAMBO is not efficient when outgoing particles have masses greater than
the half of the available energy, which could be the case for a charged
heavy lepton decaying into a neutral heavy lepton and a virtual or real
W boson). The random number generator used is RANMAR from the CERN
Program Library.
References
[1] R. Kleiss, W.J. Sterling and S.D. Ellis, Comp. Phys. Comm.
40 (1986) 359.
[2] T. Sjostrand, Comp. Phys. Comm. 82 (1994) 74.
[3] E. Barberio and Z. Was, Comp. Phys. Comm. 79 (1994) 291.
[4] CERN Program Library, CN Division, CERN, Geneva.