Monte Carlo simulation for jet fragmentation in SUSY QCD

We present results from a new Monte Carlo simulation for jet fragmentation in QCD and SUSY QCD for large primary energies $\sqrt{s}$ up to ${10}^{16}$ GeV. In the case of SUSY QCD the simulation takes into account not only gluons and quarks as cascading particles, but also their supersymmetric partners. A new model-independent hadronization scheme is developed, in which the hadronization functions are found from CERN LEP data. An interesting feature of SUSY QCD is the prediction of a sizable flux of the lightest supersymmetric particles (LSPs) if R parity is conserved. About $10\%$ of the jet energy is transferred to LSPs which, owing to their harder spectra, constitute an important part of the spectra for large ${x=E/E}_{\mathrm{jet}}.$ Spectra of protons and secondary particles (photons and neutrinos) are also calculated. These results have implications for the decay of superheavy particles with masses up to the GUT scale, which have been suggested as a source of ultrahigh energy cosmic rays.