TeV and superheavy mass scale particles from supersymmetric topological defects, the extragalactic gamma-ray background, and the highest energy cosmic rays

Cosmic topological defects in a wide class of supersymmetric theories can simultaneously be sources of Higgs bosons of mass{approximately}supersymmetry breaking scale{approximately}TeV , as well as superheavy gauge bosons of mass{approximately}{eta}{gt}1 TeV , {eta} being the gauge symmetry breaking scale. Decay of these Higgs and gauge bosons may contribute significantly to the extragalactic diffuse {gamma} -ray background (EDGRB) above {approximately}10 GeV and explain the highest energy cosmic ray (HECR) flux above {approximately}10{sup 11} GeV , respectively. Cosmic strings with {eta} much above 10{sup 14} GeV overproduce both HECR and EDGRB, and hence are ruled out, {ital if} massive particle radiation is their dominant energy loss mechanism. {copyright} {ital 1998} {ital The American Physical Society}