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

$\mathit b_{2}({{\mathit \chi}_{{{c2}}}})/\mathit b_{2}({{\mathit \chi}_{{{c1}}}}$) Magnetic quadrupole transition amplitude ratio

INSPIRE   JSON  (beta) PDGID:
M071QBR
VALUE ($ 10^{-2} $) EVTS DOCUMENT ID TECN  COMMENT
$\bf{ 60 \pm31}$ OUR AVERAGE
$74$ $\pm40$ 253k 1
ABLIKIM
2017N
 BES3 ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$
$37$ ${}^{+53}_{-47}$ 59k 2
ARTUSO
2009
CLEO ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$
1  Statistical and systematic errors combined. Derived from the reported measurement of ${{\mathit b}_{{{2}}}}({{\mathit \chi}_{{{c1}}}})/{{\mathit b}_{{{2}}}}({{\mathit \chi}_{{{c2}}}}$) = $1.35$ $\pm0.72$.
2  Statistical and systematic errors combined. Using values from fits with floating $\mathit M2$ amplitudes $\mathit a_{2}({{\mathit \chi}_{{{c1}}}}$), $\mathit a_{2}({{\mathit \chi}_{{{c2}}}}$), $\mathit b_{2}({{\mathit \chi}_{{{c1}}}}$), $\mathit b_{2}({{\mathit \chi}_{{{c2}}}}$) and fixed $\mathit E3$ amplitudes of $\mathit a_{3}({{\mathit \chi}_{{{c2}}}}$) = $\mathit b_{3}({{\mathit \chi}_{{{c2}}}}$) = 0. Not independent of values for $\mathit b_{2}({{\mathit \chi}_{{{c1}}}{(1P)}}$) and $\mathit b_{2}({{\mathit \chi}_{{{c2}}}{(1P)}}$) from ARTUSO 2009.
References