Reasoning:
- Dirac quantization forces any free magnetic charge to be much larger than the electron’s electric charge, so monopoles are heavily ionizing and — unlike generic massive cosmic-ray products — are stopped by ordinary matter despite high production velocity. The stopping loophole of the cosmic-ray argument therefore closes itself for monopoles: cosmic-ray-produced monopoles accumulate in Earth and the Sun just as collider-produced ones would.
- Billions of years of such accumulation with no macroscopic effect means any monopole that can be produced at these energies cannot catalyze nucleon decay at an appreciable rate.
- Independently, nucleon-decay-catalyzing monopoles arise in grand unified theories at ≥1e15 GeV, far beyond the 14 TeV available; and even a hypothetical light catalyzing monopole traversing Earth was calculated (CERN-2003-001) to consume only ~1 microgram of matter before exiting.
Validity verdict (step 6)
Reconstruction: three independent sub-inferences, each traced. (1) Dirac quantization forces a large magnetic charge, hence heavy ionization, hence stopping in ordinary matter even at cosmic-ray boosts - this self-closes the cosmic-ray argument’s stopping loophole for monopoles, so accumulation-without-effect over Gyr bounds catalysis. (2) Catalyzing (GUT) monopoles sit at >=1e15 GeV, ~1e11 beyond reach - a scale mismatch. (3) Even a hypothetical light catalyzer consumes ~1 ug before exit (premise from CERN-2003-001, priced downstream). The disjunctive redundancy makes the overall inference robust; valid conditional on premises.