Measurement of the (Sigma)over-bar(-) lifetime and direct comparison with the Sigma(+) lifetime

We have measured the lifetime of the (-) using the Fermilab, Proton Center 375 GeV/c charged hyperon beam. We obtained (80.43+/-0.80+/-0.14) ps. We also measured the lifetime of the Sigma(+), obtaining (80.38 +/-0.40+/-0.14) ps, in agreement with the Particle Data Group value. A direct comparison between the two lifetimes from the ratio of the decay curves gives a fractional lifetime difference of Delta tau/ =(-0.06+/-1.12)%, consistent with equal lifetimes for baryon and antibaryon as required by CPT invariance.