O-28 - Super-K bound on GUT-monopole flux times catalysis cross section from solar non-observation
The bound is stated as an explicit function of the catalysis cross section sigma_0 and monopole velocity beta_M, so its model dependence is transparent. It assumes monopole accumulation at the solar center, a proton-decay pi+ branching fraction f_pi+ ~ 0.5 (typical of GUT models), negligible monopole-antimonopole annihilation, and a capture efficiency computed from monopole energy loss in the Sun (which degrades above ~10^17 GeV monopole mass). Also tighter than the old-neutron-star X-ray limit F_M (sigma_0/1mb) < 3r x 10^-23 cm^-2 s^-1 sr^-1 even at its most stringent (r=1).
Link to original
Why this is evidence
This is the model-space translation of the Super-K null: it excludes the joint region (flux near the Parker bound) x (strong-interaction-scale catalysis cross section) that H-20 posits, by many orders of magnitude relative to direct flux limits. H-20 predicts the true flux-times-cross-section product sits at a level such a search would reach; H-41 predicts any bound however deep stays null. The bound’s model dependence (solar accumulation, pion branching, capture efficiency degrading above ~10^17 GeV monopole mass) marks where H-20 could survive it, which is why the discrimination is strong but not total.