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

Ajinenko, I.; Akimenko, S.; Britvich, G.; Britvich, I.; Datsko, K.; Filin, A.; Inyakin, A.; Konstantinov, A.; Konstantinov, V.; Korolkov, I.; Leontiev, V.; Novikov, V.; Obraztsov, V.; Polyakov, V.; Romanovsky, V.; Shelikhov, V.; Smirnov, N.; Soldatov, M.; Tchikilev, O.; Usenko, E.; Vasiliev, M.; Vlasov, E.; Yakimchuk, V.; Yushchenko, O.; Bolotov, V.; Laptev, S.; Lebedev, V.; Pastsjak, A.; Polyarush, A.; Sirodeev, R.

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

Authors

Description

The decay $K^{-} \to μ^{-} \barν π^{0}$ 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 $λ_{+}$ and $λ_{0}$ slope parameters of the decay formfactors $f_{+}(t)$, $f_{0}(t)$ have been measured : $λ_{+}= 0.0321 \pm 0.004$(stat) $\pm 0.002$(syst) $λ_{0}= 0.0209 \pm 0.004$(stat) $\pm 0.002$(syst); the correlation $d λ_{0}/d λ_{+}=-0.46$ 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