FORWARD-BACKWARD ASYMMETRY IN ${{\boldsymbol K}^{\pm}}$ DECAYS

A$_{FB}({{\boldsymbol K}}{}^{\pm{}}_{{{\boldsymbol \pi}} {{\boldsymbol \mu}} {{\boldsymbol \mu}} }$) = ${\Gamma\mathrm {(cos({{\boldsymbol \theta}}_{ {{\boldsymbol K}} {{\boldsymbol \mu}} })>0)}−\Gamma\mathrm {(cos({{\boldsymbol \theta}}_{ {{\boldsymbol K}} {{\boldsymbol \mu}} })<0)}\over \Gamma\mathrm {(cos({{\boldsymbol \theta}}_{ {{\boldsymbol K}} {{\boldsymbol \mu}} })>0)}+\Gamma\mathrm {(cos({{\boldsymbol \theta}}_{ {{\boldsymbol K}} {{\boldsymbol \mu}} })<0)}}$ INSPIRE search

VALUE CL% DOCUMENT ID TECN
$\bf{<0.023}$ 90 1
BATLEY
2011A
NA48
1  BATLEY 2011A gives a corresponding value of the asymmetry A$_{FB}$ = $-0.024$ $\pm0.018$.
  References:
BATLEY 2011A
PL B697 107 New Measurement of the ${{\mathit K}^{\pm}}$ $\rightarrow$ ${{\mathit \pi}^{\pm}}{{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ Decay