Prefer a chat interface with context about you and your work?
Improved measurement of the pseudoscalar decay constant<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>f</mml:mi></mml:mrow><mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mi>s</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:mrow></mml:msub></mml:mrow></mml:math>
We present a new determination of ${f}_{{D}_{s}}$ using 5 million ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}c\overline{c}$ events obtained with the CLEO II detector. Our value is derived from our new measured ratio $\ensuremath{\Gamma}{(D}_{s}^{+}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}\ensuremath{\nu})/\ensuremath{\Gamma}{(D}_{s}^{+}\ensuremath{\rightarrow}\ensuremath{\varphi}{\ensuremath{\pi}}^{+})=0.173\ifmmode\pm\else\textpm\fi{}0.023\ifmmode\pm\else\textpm\fi{}0.035$. Using $\mathcal{B}{(D}_{s}^{+}\ensuremath{\rightarrow}\ensuremath{\varphi}{\ensuremath{\pi}}^{+})=(3.6\ifmmode\pm\else\textpm\fi{}0.9)$%, we extract ${f}_{{D}_{s}}=(280\ifmmode\pm\else\textpm\fi{}19\ifmmode\pm\else\textpm\fi{}28\ifmmode\pm\else\textpm\fi{}34) \mathrm{MeV}$. We compare this result with various model calculations.