Several recent articles assert that the increasingly precise null results of Bhabha scattering imply ‘‘model-independent’’ increasing lower bounds upon the lifetime of any neutral particle whose decay is hypothesized to yield the sharp lines of the GSI ‘‘(${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{-}}$) puzzle.’’ We discuss here reasons why such conclusions must be considered as artifacts of the assumptions made in the analysis, and not as valid scientific deductions from the data alone. Furthermore, we show that when such data are combined with additional assumptions sufficient to allow an inference about the lifetime, then the conclusion is inevitably dependent explicitly or implicitly upon the model assumed for the particle decay. In addition, we discuss why the limits asserted upon the lifetime of such a particle from the high precision agreement for ${\mathit{g}}_{\mathit{e}}$-2 between experiment and theoretical quantum electrodynamics apply only to an elementary particle, but not to a composite particle, and especially not to a leptonic composite. In the end, no valid limits upon the composite particle lifetime seems to exist at present. We also consider, in the context of the general partial width data problem, the additional experimental data which could suffice to sustain a purely empirical limit upon the lifetime, and observe that all of the present data are consistent with a composite particle with a significant amplitude in the four lepton (${\mathit{e}}^{+}$${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{-}}$${\mathit{e}}^{\mathrm{-}}$) ‘‘quadronium’’ sector. Finally, it is shown that recent preliminary Bhabha inelastic (${\mathit{e}}^{+}$${\mathit{e}}^{+}$γ) data, if confirmed, would imply the crude but genuinely empirical upper bound upon the resonance lifetime of about ${\mathrm{\tau }}_{\max }$∼2×${10}^{\mathrm{-}11}$ sec≥τ.

• Received 28 July 1992

DOI:https://doi.org/10.1103/PhysRevC.47.351