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Manuscript Title: TWISTER: a Monte Carlo for QCD high-p(transverse) scattering.
Authors: G. Ingelman
Program title: TWISTER VERSION 1.2
Catalogue identifier: AAXG_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 46(1987)217
Programming language: Fortran.
Computer: IBM 3084Q.
Operating system: MVS XA.
RAM: 728K words
Word size: 32
Keywords: Hard hadron-hadron Collisions, Qcd parton scattering, High p(transverse) Particles, Prompt photons, Higher twist, Prompt mesons, Monte carlo simulation, Hadronization, Event simulation, Particle physics, Elementary.
Classification: 11.2, 11.5.

Subprograms used:
Cat Id Title Reference
AAFP_v1_0 JETSET 6.2 CPC 39(1986)347
AAFP_v2_0 JETSET 6.3 CPC 43(1987)367

Nature of problem:
Production of high-p(transverse) particles in hadron-hadron scattering arise through the point-like interaction of constituent partons (quarks and gluons) as described by perturbative QCD. The formation of final state particles occur dominantly through a low momentum-transfer hadronization process, but also via the higher twist mechanism giving prompt mesons.

Solution method:
Perturbative QCD matrix elements are used for the underlying parton level interaction as well as the higher twist mechanism. For the soft hadronization process of the scattered partons and the hadron remnant spectators the Lund string model is employed. Included are all leading order 2 -> 2 QCD processes, single and double prompt photon production processes as well as higher twist processes giving prompt mesons and glueballs at high p(transverse). Complete events are simulated making direct comparsion with any experimental observable possible.

Properties of high p(transverse) jets produced at collider energies are not well described since multiple gluon radiation effects are not included.

Unusual features:
A random number generator and the ordinary gamma function are required.

Running time:
The time needed to generate one event is 0.02 to 0.08 seconds depending on energy and p(transverse) scale.