${{\mathit \Upsilon}{(4S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \Upsilon}{(D)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \eta}}{{\mathit \Upsilon}{(1S)}}$  Decay Mode Summary INSPIRE   JSON  (beta) PDGID:
M047.24
Mode (*) Fraction ($\Gamma_i$ / $\Gamma$) Scale Factor/
Conf. Level		 P(MeV/c)  
$\Gamma_{26}$ ${{\mathit \Upsilon}{(4S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \Upsilon}{(D)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \eta}}{{\mathit \Upsilon}{(1S)}}$ $<2.3 \times 10^{-5}$ CL= 90%
Category: Double Radiative Decays
The following data is related to the above value:
$\Gamma({{\mathit \Upsilon}{(4S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \Upsilon}{(D)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \eta}}{{\mathit \Upsilon}{(1S)}})/\Gamma_{\text{total}}$
$\Gamma_{26}/\Gamma$