MULTIPOLE AMPLITUDES IN ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \chi}_{{{c2}}}{(1P)}}$ RADIATIVE DECAY

$\mathit b_{2}$ = $\mathit M2/\sqrt {\mathit E1{}^{2}+\mathit M2{}^{2}+\mathit E3{}^{2} }$ Magnetic quadrupole fractional transition amplitude

INSPIRE   JSON  (beta) PDGID:
M057QB2
VALUE ($ 10^{-2} $) EVTS DOCUMENT ID TECN  COMMENT
$\bf{ 1.9 \pm0.9}$ OUR AVERAGE  Error includes scale factor of 1.4.  See the ideogram below.
$1.7$ $\pm0.8$ $\pm0.2$ 89k 1
ABLIKIM
2017N
 BES3 ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$
$4.6$ $\pm1.0$ $\pm1.3$ 13.8k 2
ABLIKIM
2011I
 BES3 ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$, ${{\mathit \gamma}}{{\mathit K}^{+}}{{\mathit K}^{-}}$
$0.2$ $\pm1.5$ $\pm0.4$ 19.8k 3
ARTUSO
2009
CLEO ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$
$-5.1$ ${}^{+5.4}_{-3.6}$ 721 2
ABLIKIM
2004I
 BES2 ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$, ${{\mathit \gamma}}{{\mathit K}^{+}}{{\mathit K}^{-}}$
$13.2$ ${}^{+9.8}_{-7.5}$ 441 4
OREGLIA
1982
CBAL ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$
• • We do not use the following data for averages, fits, limits, etc. • •
$1.0$ $\pm1.3$ $\pm0.3$ 19.8k 4
ARTUSO
2009
CLEO ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$
1  Correlated with ${{\mathit a}_{{{2}}}}$, ${{\mathit a}_{{{3}}}}$, and ${{\mathit b}_{{{3}}}}$ with correlation coefficients $\rho _{{{\mathit a}_{{{2}}}} {{\mathit b}_{{{2}}}}}$ = $-0.605$, $\rho _{{{\mathit a}_{{{3}}}} {{\mathit b}_{{{2}}}}}$ = $-0.422$, and $\rho _{{{\mathit b}_{{{2}}}} {{\mathit b}_{{{3}}}}}$ = $0.384$.
2  From a fit with floating $\mathit M2$ and $\mathit E3$ amplitudes $\mathit b_{2}$ and $\mathit b_{3}$.
3  From a fit with floating $\mathit M2$ and $\mathit E3$ amplitudes $\mathit a_{2}$, $\mathit b_{2}$, and $\mathit a_{3}$, and $\mathit b_{3}$.
4  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.

           $\mathit b_{2}$ = $\mathit M2/\sqrt {\mathit E1{}^{2}+\mathit M2{}^{2}+\mathit E3{}^{2} }$ Magnetic quadrupole fractional transition amplitude ($ 10^{-2} $)
References