D. A. Harris

Polarization of Λ and Λ produced by 800-GeV protons☆

Abstract We have measured the polarization of Λ and Λ hyperons produced by 800 GeV protons on a Be target at a fixed targeting angle of 4.8 mrad. Comparison with previous data at 400 GeV production energy and twice the targeting angle shows no significant energy dependence for the Λ polarization. This is in striking contrast to the energy dependence found for σ+ and Ξ− polarizations. We find no evidence for Λ polarization at 800 GeV.

Search for the lepton-family number violating decays KL→π0μ±e∓

Abstract We have carried out at Fermilab the first search for the lepton-family number violating decay K L → π 0 μ ± e ∓ . There were no events observed. By normalizing to K L → π + π − π 0 decays collected simultaneously, the 90% confidence level upper limit on 1 2 [ BR (K L →π 0 μ + e − )+ BR (K L →π 0 μ − e + )] was determined to be 3.1×10 −9 .

Limit on the branching ratio of KL → π0e+e-

We report the results of a search for the decay [ital K][sub [ital L]][r arrow][pi][sup 0][ital e+][ital e[minus]] conducted by E799 at Fermilab. The largest contribution to this decay mode is expected to be [ital CP] violating. Observations of this decay could either confirm the standard model mechanisms for [ital CP] violation or point to physics beyond the standard model. No such events were seen in our search. The 90% confidence level upper limit is determined to be [ital B]([ital K][sub [ital L]][r arrow][pi][sup 0][ital e+][ital e[minus]])[lt]4.3[times]10[sup [minus]9].

A limit on the lepton-family number violating process π0 → μ±e∓

Abstract A FNAL E799 Collaboration has carried out a search for the lepton-family number violating decay π0 → μ±e∓ using π0s produced from KL → π0π0π0 decays in flight. No events were observed. Assuming that lepton-family number violation is charge independent, the 90% confidence level upper limit on 1 2 [ BR (π 0 → μ + e − ) + BR (π 0 → μ − e + )] was determined to be 8.6 × 10−9.

Measurement of the branching ratio and form factor of KL→μ+μ- γ

We report on a measurement of the decay

Measurement of the branching ratio of KLe+e-

K_Lrightarrowmu^+mu^-gamma

Search for the decay KL0→π0π0γ

from Fermilab experiment E799. We observe

Limit on the branching ratio of KL→ π0μ+μ-

207

CPT tests in the neutral kaon system.

candidate signal events with an estimated background of

Measurement of the branching ratio and a study of CP for the leptonic decay KL-->e+e-e+e-

10.5 pm 4.0