An experimental study of the decay mode KL0 → π±μ∓ν

In a study of 70 000 KL0 decays, a sample of 9635 KL0 → π±μ∓ν candidates has been isolated. A study of the Dalitz plot is presented. The data is found to be in agreement with V-A theory and with other recent measurements of the parameters ⨍ + (q 2 ) and ξ(q 2 ) = ⨍ − (q 2 )/⨍ + (q 2 ) . The results are λ+ = 0.085 ± 0.015, ξ(0) = −1.5 ± 0.7, λ− = 0.030 ± 0.060, Λ = 0.15−0.11+0.17, λ0 = −0.043 ± 0.039. The parameters are defined in the next.