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MULTIPOLE AMPLITUDES IN ${{\mathit \chi}_{{c1}}{(1P)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit J / \psi}{(1S)}}$

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

INSPIRE   PDGID:

M055A1

VALUE ($ 10^{-2} $) EVTS DOCUMENT ID TECN  COMMENT $\bf{ -6.7 \pm0.9}$ OUR AVERAGE  Error includes scale factor of 2.6.  See the ideogram below. $-7.40$ $\pm0.33$ $\pm0.34$ 164k 1 ABLIKIM 2017 N BES3 ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ $-6.26$ $\pm0.63$ $\pm0.24$ 39k ARTUSO 2009 CLEO ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ $0.2$ $\pm3.2$ $\pm0.4$ 2090 AMBROGIANI 2002 E835 ${{\mathit p}}$ ${{\overline{\mathit p}}}$ $\rightarrow$ ${{\mathit \chi}_{{c1}}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit \gamma}}$ $-0.2$ ${}^{+0.8}_{-2.0}$ 921 OREGLIA 1982 CBAL ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \chi}_{{c1}}}{{\mathit \gamma}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit \gamma}}{{\mathit \gamma}}$ 1  Correlated with ${{\mathit b}_{{2}}}$ with correlation coefficient $\rho _{ {{\mathit a}_{{2}}} {{\mathit b}_{{2}}} }$ = 0.133.

$\mathit a_{2}$ = $\mathit M2/\sqrt {\mathit E1{}^{2}+\mathit M2{}^{2} }$

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 ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \chi}_{{c1}}}$ , ${{\mathit \chi}_{{c2}}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit \gamma}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit \gamma}}$ OREGLIA 1982 PR D25 2259 Study of the Reaction ${{\mathit \psi}^{\,'}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit J / \psi}}$ Also Private Comm. Private Communication

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