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Manuscript Title: Decay of Super-Heavy particles: User guide of the SHdecay program.
Authors: C. Barbot
Program title: SHdecay
Catalogue identifier: ADSL
Journal reference: Comput. Phys. Commun. 157(2004)63
Programming language: C with STL C++ library.
Computer: PC.
Operating system: Linux KDE and Suse 8.1.
Keywords: Particle physics, Elementary, Phenomenological model, Superheavy particles, Fragmentation functions, DGLAP equations, Supersymmetry, MSSM, UHECR.
Classification: 11.6.

Nature of problem:
Obtaining the energy spectra of the final stable decay products (protons, photons, electrons, the three species of neutrinos and the LSPs) of a decaying super-heavy X particle, within the framework of the Minimal Supersymmetric Standard Model (MSSM). It can be done numerically by solving the full set of DGLAP equations in the MSSM for the perturbative evolution of the fragmentation functions Dp2p1 (x,Q) of any particle p1 into any other p2 (x is the energy fraction carried by the particle p2 and Q its virtuality), and by treating properly the different decay cascades of all unstable particles and the final hadronization of quarks and gluons. In order to obtain proper results at very low values of x (up to x~10 -13), NLO color coherence effects have been included by using the Modified Leading Log Approximation (MLLA).

Solution method:
The DGLAP equations are solved by a four order Runge-Kutta method with a fixed step.

Running time:
Around 35 hours for the first run, but the most time consuming sub-programs can be run only once for most applications.