Adler S, Atiya MS, Chiang IH, Diwan MV, Frank JS, Haggerty JS, Kettell SH, Kycia TF, Li KK, Littenberg LS, Sambamurti A, Stevens A, Strand RC, Witzig C, Komatsubara TK, Kuriki M, Muramatsu N, Sugimoto S, Inagaki T, Kabe S, Kobayashi M, Kuno Y, Sato T, Shinkawa T, Yoshimura Y, Kishi Y
Brookhaven National Laboratory, Upton, New York 11973, USA.
Phys Rev Lett. 2000 Sep 11;85(11):2256-9. doi: 10.1103/PhysRevLett.85.2256.
We report the first measurement of a structure-dependent component in the decay K+-->&mgr;(+)nu(&mgr;)gamma. Using the kinematic region where the muon kinetic energy is greater than 137 MeV and the photon energy is greater than 90 MeV, we find that the absolute value of the sum of the vector and axial-vector form factors is |F(V)+F(A)| = 0.165+/-0.007+/-0.011. This corresponds to a branching ratio of B(SD+) = (1.33+/-0.12+/-0.18)x10(-5). We also set the limit -0. 04<F(V)-F(A)<0.24 at 90% C.L.
我们报告了在衰变K⁺→μ⁺ν(μ)γ中对结构相关分量的首次测量。利用μ子动能大于137 MeV且光子能量大于90 MeV的运动学区域，我们发现矢量和轴矢量形状因子之和的绝对值为|F(V)+F(A)| = 0.165±0.007±0.011。这对应于分支比B(SD⁺) = (1.33±0.12±0.18)×10⁻⁵。我们还在90%置信水平下设定了-0.04<F(V)-F(A)<0.24的限制。
