Year: 2000
Type: article
Abstract: We report the first measurement of a structure-dependent component in the decay ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\nu}}_{\ensuremath{\mu}}\ensuremath{\gamma}$. 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 $|{F}_{V}{+F}_{A}|\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.165\ifmmode\pm\else\textpm\fi{}0.007\ifmmode\pm\else\textpm\fi{}0.011$. This corresponds to a branching ratio of $B({\mathrm{SD}}^{+})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}(1.33\ifmmode\pm\else\textpm\fi{}0.12\ifmmode\pm\else\textpm\fi{}0.18)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$. We also set the limit $\ensuremath{-}0.04<{F}_{V}{\ensuremath{-}F}_{A}<0.24$ at $90%$ C.L.
Source: Physical Review Letters
Authors: S. Adler, M. Atiya, I-H. Chiang, M. Diwan, J. Frank, J. Haggerty, S. Kettell, T. Kycia, K. Li, L. Littenberg, A. Sambamurti, A. Stevens, R. Strand, C. Witzig, T. Komatsubara, M. Kuriki, N. Muramatsu, S. Sugimoto, T. Inagaki, S. Kabe, M. Kobayashi, Y. Kuno, T. Sato, T. Shinkawa, Y. Yoshimura, Y. Kishi, T. Nakano, M. Ardebili, M. Convery, M. Ito, D. Marlow, R. McPherson, P. Meyers, F. Shoemaker, A. Smith, J. Stone, M. Aoki, E. Blackmore, P. Bergbusch, D. Bryman, A. Konaka, J. Macdonald, J. Mildenberger, T. Numao, P. Padley, J.-M. Poutissou, R. Poutissou, G. Redlinger, P. Kitching, R. Soluk
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W25780387