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   JSON  (beta) 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
2017N
 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
1993E
 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