PROGRAM SUMMARY
Title of program:
LUCIAE version 3
Catalogue identifier:
ADJN
Ref. in CPC:
116(1999)353
Distribution format: uuencoded compressed tar file
Operating system: HP-UX 10.20
High speed store required:
90K words
Number of bits in a word:
32
Number of lines in distributed program, including test data, etc:
48859
Programming language used: Fortran
Computer: HP Model 715/100
Other versions of this program:
Cat. Id. Title Ref. in CPC ADBS LUCIAE version 2 90(1995)121
Nature of physical problem:
The experiments of relativistic pA and AA collisions reveal that high
energy heavy-ion collisions have some features which can not be
understood by the simple superposition of independent nucleon-nucleon
collisions. They indicate clearly that the collective effects are
important in the relativistic pA and AA collisions. Formation of a QGP
is often suggested to be a candidate to account for some of these
collective effects. Could we understand those new features in pA and AA
collisions by conventional physics (on which LUCIAE is based)? What is
the limit of a model to explain the experimental data without the
formation of QGP within a reasonable margin of flexibility of the model?
The Monte-Carlo generator, LUCIAE is built in an attempt to answer these
questions.
Method of solution
When many strings or colour dipoles are formed in relativistic pA and AA
collisions, it is natural to ask if there is some interaction among
those strings close by so that both the emission of gluonic
bremsstrahlung as well as the fragmentation properties can be affected
by the large common energy density of the string cluster (Colour Rope).
The Firecracker Model is developed to study such a collective effect.
Moreover, many hadrons are produced in a small space-time volume through
fragmentation of these strings, which implies that they will interact
with each other and with the surrounding cold spectator matter. The
rescattering effect on the distributions of the final state hadrons is
also included in LUCIAE program.
Summary of revisions
(1) The initialization of hadrons in the space-time is modified.
(2) Much more inelastic channels and their reverse reactions have been
included in the rescattering sector.
(3) The annihilation of pbar and Alphabar in nuclear matter is taken
into account.
(4) The effect of firecracker gluons on the fragmentation of a string
has been included.
(5) The sizes of arrays have been enlarged. The values of a few
parameters are adjusted and a few bugs are fixed.
Restrictions on the complexity of the problem
At very high energies (sqrt(s) in the TeV range), especially for
collisions of massive nuclei, certain arrays need to be expanded to
accommodate the large number of particles produced.
Typical running time
Depends on the type of collision and energy. Three examples of central
collisions (b=0) running on a HP Station:
32S + 32S plab = 200 A GeV/c: ~0.6 minutes/event
207Pb + 207Pb plab = 158 A GeV/c: ~9 minutes/event
197Au + 197Au sqrt(s) = 200 GeV: ~80 minutes/event