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MULTIPOLE AMPLITUDES IN ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \chi}_{{{c1}}}{(1S)}}$ RADIATIVE DECAY

$\mathit b_{2}$ = $\mathit M2/\sqrt {\mathit E1{}^{2}+\mathit M2{}^{2} }$ Magnetic quadrupole fractional transition amplitude

INSPIRE   PDGID:

M055QB2

VALUE ($ 10^{-2} $) EVTS DOCUMENT ID TECN  COMMENT $\bf{ 2.5 \pm0.4}$ OUR AVERAGE $2.29$ $\pm0.39$ $\pm0.27$ 164k 1 ABLIKIM 2017 N BES3 ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ $2.76$ $\pm0.73$ $\pm0.23$ 39k ARTUSO 2009 CLEO ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ $7.7$ ${}^{+5.0}_{-4.5}$ 921 OREGLIA 1982 CBAL ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ 1  Correlated with ${{\mathit a}_{{{2}}}}$ with correlation coefficient $\rho _{{{\mathit a}_{{{2}}}} {{\mathit b}_{{{2}}}}}$ = 0.133.

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