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MULTIPOLE AMPLITUDES IN ${{\mathit \chi}_{{c2}}{(1P)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit J / \psi}{(1S)}}$ RADIATIVE DECAY

$\mathit a_{3}$ = $\mathit E3/\sqrt {\mathit E1{}^{2}+\mathit M2{}^{2}+\mathit E3{}^{2} }$ Electric octupole fractional transition amplitude

INSPIRE   PDGID:

M057A2

VALUE ($ 10^{-2} $) EVTS DOCUMENT ID TECN  COMMENT $\bf{ -0.3 \pm1.0}$ OUR AVERAGE  Error includes scale factor of 1.3.  See the ideogram below. $-1.3$ $\pm0.9$ $\pm0.4$ 89k 1 ABLIKIM 2017 N BES3 ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ $1.7$ $\pm1.4$ $\pm0.3$ 19.8k 2 ARTUSO 2009 CLEO ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ $2.0$ ${}^{+5.5}_{-4.4}$ $\pm0.9$ 5908 AMBROGIANI 2002 E835 ${{\mathit p}}$ ${{\overline{\mathit p}}}$ $\rightarrow$ ${{\mathit \chi}_{{c2}}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit \gamma}}$ $0$ ${}^{+6}_{-5}$ 1904 ARMSTRONG 1993 E E760 ${{\mathit p}}$ ${{\overline{\mathit p}}}$ $\rightarrow$ ${{\mathit \chi}_{{c2}}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit \gamma}}$ 1  Correlated with ${{\mathit a}_{{2}}}$, ${{\mathit b}_{{2}}}$, and ${{\mathit b}_{{3}}}$ with correlation coefficients $\rho _{ {{\mathit a}_{{2}}} {{\mathit a}_{{3}}} }$ = $0.733$, $\rho _{ {{\mathit a}_{{3}}} {{\mathit b}_{{2}}} }$ = $-0.422$, and $\rho _{ {{\mathit a}_{{3}}} {{\mathit b}_{{3}}} }$ = $-0.024$. 2  From a fit with floating $\mathit M2$ and $\mathit E3$ amplitudes $\mathit a_{2}$, $\mathit b_{2}$, and $\mathit a_{3}$, and $\mathit b_{3}$.

$\mathit a_{3}$ = $\mathit E3/\sqrt {\mathit E1{}^{2}+\mathit M2{}^{2}+\mathit E3{}^{2} }$ Electric octupole fractional transition amplitude ($ 10^{-2} $)

References:

ABLIKIM 2017N PR D95 072004 Measurement of Higher-Order Multipole Amplitudes in ${{\mathit \psi}{(3686)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \chi}_{{c1,2}}}$ with ${{\mathit \chi}_{{c1,2}}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit J / \psi}}$ and Search for the Transition ${{\mathit \eta}_{{c}}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit J / \psi}}$ ARTUSO 2009 PR D80 112003 Higher-Order Multipole Amplitudes in Charmonium Radiative Transitions AMBROGIANI 2002 PR D65 052002 Study of the Angular Distributions of the Reactions ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \chi}_{{c1}}}$ , ${{\mathit \chi}_{{c2}}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit \gamma}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit \gamma}}$ ARMSTRONG 1993E PR D48 3037 Study of the Angular Distribution of the Reaction ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \chi}_{{c2}}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit \gamma}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit \gamma}}$

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