Gavin Salam's web
The core of the program consists of routines for adding a gluon to a colour dipole, so as to produce two colour dipoles. The transverse position and rapidity of the gluon are chosen randomly, in accord with the distributions derived by Mueller in Nucl. Phys. B415 (1994) 373. The branching of one dipole into two is repeated recursively until the rapidity of any new gluons would be larger than the rapidity to which the onium is being evolved, giving the complete dipole structure of the onium. This can be done for any number of initial onia, of arbitrary size.

The resulting dipole structures can then be processed in whichever way the user wishes. For example one can make a histogram of the number of dipoles as a function of their size and position, to help understand which impact parameters are relevant for onium-onium interaction.

One of the main advantages of using the Monte Carlo approach over analytical techniques, is that it is very easy to determine quantities which depend on the correlations between different dipoles in the same onium. The OEDIPUS distribution includes example routines for doing this.

In particular, there are highly optimised routines for determining the multiple scattering interactions between pairs of onia. These store the probability distribution of the single interaction (1-pomeron) for each impact parameter allowing to reuse the data from a run to determine many different quantities (e.g. two-pomeron interaction, fully unitarised amplitude, cross section for any number of cut pomerons, etc...).

Back to OEDIPUS home page.
Gavin Salam
June 3, 1996