${{\mathit \Upsilon}{(1S)}}$ $\rightarrow$ ${{\mathit e}^{\pm}}{{\mathit \mu}^{\mp}}$   Decay Mode Summary INSPIRE   PDGID:
M049.196
Mode (*) Fraction ($\Gamma_i$ / $\Gamma$) Scale Factor/
Conf. Level		 P(MeV/c)  
$\Gamma_{127}$ ${{\mathit \Upsilon}{(1S)}}$ $\rightarrow$ ${{\mathit e}^{\pm}}{{\mathit \mu}^{\mp}}$ $<3.9 \times 10^{-7}$ CL= 90% 4730
Category: Lepton Family number ($\mathit LF$) violating modes
Note: (LF) Lepton family number conservation means separate conservation of each of $\mathit L_{{{\mathit e}}}$, $\mathit L_{{{\mathit \mu}}}$, $\mathit L_{{{\mathit \tau}}}$.
The following data is related to the above value:
$\Gamma($ ${{\mathit \Upsilon}{(1S)}}$ $\rightarrow$ ${{\mathit e}^{\pm}}{{\mathit \mu}^{\mp}}$ $)/\Gamma_{\text{total}}$
$\Gamma_{127}/\Gamma$