Study of the K- -> mu- nu pi0 decay

Abstract

The decay $K^{-}\to \hat{I}{¼}^{-}\bar{\hat{I}}½\ddot{I}{€}^0$ has been studied using in-flight decays detected with ``ISTRA+'' setup operating in the 25 GeV negative secondary beam of the U-70 PS. About 112K events were used for the analysis. The $\hat{I}{»}_{+}$ and $\hat{I}{»}_0$ slope parameters of the decay formfactors $f_{+}(t)$, $f_0(t)$ have been measured : $\hat{I}{»}_{+}=0.0321\pm 0.004$(stat) $\pm 0.002$(syst) $\hat{I}{»}_0=0.0209\pm 0.004$(stat) $\pm 0.002$(syst); the correlation $d\hat{I}{»}_0/d\hat{I}{»}_{+}=-0.46$ The limits on the possible tensor and scalar couplings have been derived: $f_T/f_{+}(0)=-0.021\pm 0.028$(stat) $\pm 0.014$(theory); $f_S/f_{+}(0)=0.004\pm 0.005$(stat) $\pm 0.005$(theory)

9 pages, Latex, 5 Postscript figures