PROGRAM SUMMARY
Title of program:
GRAPE-Dilepton (v1.1)
Catalogue identifier:
ADNR
Ref. in CPC:
136(2001)126
Distribution format: tar gzip file
Operating system: UNIX
High speed store required:
9MK words
Number of lines in distributed program, including test data, etc:
262390
Keywords:
Elementary particle physics, QCD, Dilepton, Lepton-pair, ep collision,
Bethe-Heitler, Z boson, Dipole form factor, Hadron tensor,
Lepton tensor, Structure function, Parton density, GRACE.
Programming language used: Fortran
Nature of problem:
A precise estimation of the cross-section of the electroweak dilepton
production in ep collisions is required in various physics analyses,
where 8~48 Feynman diagrams can contribute.
Method of solution:
The automatic calculation system GRACE is used to obtain all of the
relevant helicity amplitudes. The phase space is divided into the 3
regions according to the kinematics at the proton vertex, and the 3
different calculation methods are applied. The radiative corrections
are included using the structure function and the parton shower methods.
Restrictions:
Higgs, the proton-Z0 coupling and lepton-pair production through photon
radiation from the proton are not included. The contribution from the
resolved photon, i.e. Drell-Yan process in ep collisions is not
included.
Typical running time:
1 hour for a cross-section integration and 1 msec per 1 event for an
event generation.