Of the two astrophysical limits here, that of GEER 2000D involves considerably more refinements in its modeling. The other limits come from direct observations of stored antiprotons. See also “${{\overline{\mathit p}}}$ Partial Mean Lives” after “${{\mathit p}}$ Partial Mean Lives,” below, for exclusive-mode limits. The best (lifetime/branching fraction) limit there is $7 \times 10^{5}$ years, for ${{\overline{\mathit p}}}$ $\rightarrow$ ${{\mathit e}^{-}}{{\mathit \gamma}}$. We advance only the exclusive-mode limits to our Summary Tables.

LIMIT (years) CL% EVTS DOCUMENT ID TECN  COMMENT • • We do not use the following data for averages, fits, limits, etc. • • $> 5.0$ 90 SELLNER 2017 TRAP Penning trap $>8 \times 10^{5}$ 90 1 GEER 2000 D ${{\overline{\mathit p}}}/{{\mathit p}}$ ratio, cosmic rays $>0.28$ GABRIELSE 1990 TRAP Penning trap $>0.08$ 90 1 BELL 1979 CNTR Storage ring $>1 \times 10^{7}$ GOLDEN 1979 SPEC ${{\overline{\mathit p}}}/{{\mathit p}}$ ratio, cosmic rays $>3.7 \times 10^{-3}$ BREGMAN 1978 CNTR Storage ring 1  GEER 2000D uses agreement between a model of galactic ${{\overline{\mathit p}}}~$production and propagation and the observed ${{\overline{\mathit p}}}/{{\mathit p}}$ cosmic-ray spectrum to set this limit.

References