PROGRAM SUMMARY
Title of program:
JetViP 1.1
Catalogue identifier:
ADKC
Ref. in CPC:
119(1999)45
Distribution format: uuencoded compressed tar file
Operating system: HP-UX, IRIX, LINUX
High speed store required:
9MK words
Number of lines in distributed program, including test data, etc:
26623
Programming language used: Fortran
Computer: HP-Clusters
Nature of physical problem:
In eP- and egamma-scattering experiments, the hadronic final state can
be analysed by jet cluster algorithms, yielding inclusive single- and
dijet cross sections. These can be obtained in a continuous range of
photon virtuality. The cross sections allow the extraction of
parameters, such as alphas, Lambda MS(bar) or parton densities (also of
the virtual photon), if the respective jet cross sections are
theoretically known.
Method of solution
JetViP is a computer program for the calculation of inclusive single-
and dijet cross sections in eP- and egamma-scattering in NLO QCD. The
virtuality of the photon, radiated by the incoming electron, can be
chosen in a continuous range, reaching from photoproduction into deep
inelastic scattering. The various contributions to the full jet cross
section, including the resolved photon contributions, are implemented.
The calculation is based on the phase-space-slicing method.
The multidimensional phase-space integration is performed with the help
of the VEGAS Monte Carlo integration routine [1]. The parton
distribution functions (PDFs) from the PDFLIB are used [2] and for the
virtual photon PDF the two routines by Schuler and Sjostrand (SASGAM)
[3] and by Gluck, Reya and Stratmann (GRS) [4] are used.
Typical running time
Varies strongly from LO to NLO and depends on type of subprocess (direct
or resolved). At LO, running times of about 1 minute for a cross
section with fixed bin-size in one of the kinematical variables are
typical. At NLO, the running time for such a cross section varies
between 30 minutes (for the single resolved contributions) to 5 hours
(for the double resolved contributions).
References
[1] G.P. Lepage, J. Comp. Phys. 27 (1978) 192.
[2] H. Plothow-Besch, PDFLIB User's Manual.
URL: http://consult.cern.ch/writeups/pdflib/
[3] G.A. Schuler, T. Sjostrand, Z. Phys. C68 (1995) 607; Phys. Lett.
B 376 (1996) 193.
[4] M. Gluck, E. Reya, M. Stratmann, Phys. Rev. D54 (1996) 5515.