MULTIPOLE AMPLITUDE RATIOS IN RADIATIVE DECAYS ${{\boldsymbol \psi}{(2S)}}$ $\rightarrow$ ${{\boldsymbol \gamma}}{{\boldsymbol \chi}_{{c1}}{(1S)}}$ and ${{\boldsymbol \chi}_{{c1}}}$ $\rightarrow$ ${{\boldsymbol \gamma}}{{\boldsymbol J / \psi}{(1S)}}$

$\boldsymbol a_{2}/\boldsymbol b_{2}$ Magnetic quadrupole transition amplitude ratio INSPIRE search

VALUE EVTS DOCUMENT ID TECN  COMMENT
$-2.27$ ${}^{+0.57}_{-0.99}$ 39k 1
ARTUSO
2009
CLEO ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$
1  Statistical and systematic errors combined. Not independent of $\mathit a_{2}({{\mathit \chi}_{{c1}}}$) and $\mathit b_{2}({{\mathit \chi}_{{c1}}}$) values from ARTUSO 2009 .
  References:
ARTUSO 2009
PR D80 112003 Higher-Order Multipole Amplitudes in Charmonium Radiative Transitions