yorregos6467 yorregos6467 20-02-2024 Physics contestada A neutral pion, π0, has a lifetime of 8.4×10⁻¹⁷ sec in its own rest frame before decaying into two photons. However in a laboratory experiment, where the pions are observed to be moving, their lifetime is measured to be 4.2×10⁻¹⁶ sec.