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.

VALUE (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:

SELLNER 2017 NJP 19 083023 Improved limit on the directly measured antiproton lifetime GEER 2000D APJ 532 648 A New Limit on the ${{\overline{\mathit p}}}$ Lifetime GABRIELSE 1990 PRL 65 1317 A 1000 $−$ Fold Improvement in the Measured Antiproton Mass BELL 1979 PL 86B 215 Antiproton Lifetime Measurement in the ICE Storage Ring using Counter Technique GOLDEN 1979 PRL 43 1196 Evidence for the Existence of Cosmic Ray antiprotons BREGMAN 1978 PL 78B 174 Measurement of Antiproton Lifetime using the ICE Storage Ring