MULTIPOLE AMPLITUDE RATIOS IN RADIATIVE DECAYS ${{\boldsymbol \psi}{(2S)}}$ $\rightarrow$ ${{\boldsymbol \gamma}}{{\boldsymbol \chi}_{{c2}}{(1P)}}$ and ${{\boldsymbol \chi}_{{c2}}}$ $\rightarrow$ ${{\boldsymbol \gamma}}{{\boldsymbol J / \psi}{(1S)}}$

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

VALUE ($ 10^{-2} $)

EVTS

DOCUMENT ID

TECN

COMMENT

$-11$ ${}^{+14}_{-15}$

19.8k

ARTUSO

2009

CLEO

${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$

¹ Statistical and systematic errors combined. From a fit with floating $\mathit M2$ amplitudes $\mathit a_{2}$ and $\mathit b_{2}$, and fixed $\mathit E3$ amplitudes $\mathit a_{3}=\mathit b_{3}$=0. Not independent of values for $\mathit a_{2}({{\mathit \chi}_{{c2}}{(1P)}}$) and $\mathit b_{2}({{\mathit \chi}_{{c2}}{(1P)}}$) from ARTUSO 2009 .

References:

ARTUSO

2009

PR D80 112003

Higher-Order Multipole Amplitudes in Charmonium Radiative Transitions