0000000000311833
AUTHOR
Alessandro Bigi
Measurement of the K-S mean lifetime from pi(+)pi(-) and pi(0)pi(0) decays using K-L decays to determine the acceptance
A precision measurement of the KS mean lifetime has been performed by comparing, in the same experimental setup, the distributions of two-pion decays of neutral kaons produced by high energy proton-beryllium interactions in two targets at a relative distance variable between 112 and 160 m. The value obtained combining the results from π+π- and π0π0 decays is τS = (0.8971 ± 0.0021) 10-10 s. © Springer-Verlag 1997.
Determination of the branching ratiosΓ(K L→3π0)/Γ(K L→π+ - 0) andΓ(K L→3π0)/Γ(K L→πev)
Improved branching ratios were measured for theKL→3π0 decay in a neutral beam at the CERN SPS with the NA31 detector: $$\Gamma ({\rm K}_L \to 3\pi ^0 )/\Gamma ({\rm K}_L \to \pi ^ + \pi ^ - \pi ^0 ) = 1.611 \pm 0.037$$ and $$\Gamma ({\rm K}_L \to 3\pi ^0 )/\Gamma ({\rm K}_L \to \pi ev) = 0.545 \pm 0.010.$$ From the first number an upper limit for ΔI=5/2 and ΔI=7/2 transitions in neutral kaon decay is derived. Using older results for the Ke3/Kμ3 fraction, the 3π0 branching ratio is found to beΓ(K L →3π0)/Γ tot =(0.211±0.003), about a factor three more precise than from previous experiments.