# ${{\boldsymbol \pi}}{{\boldsymbol \pi}}{{\boldsymbol \gamma}}$ MODE INSPIRE search

VALUE (MeV) EVTS DOCUMENT ID TECN  COMMENT
$\bf{ 89 \pm17}$ OUR AVERAGE  Error includes scale factor of 1.7.
$64$ $\pm18$ $235$ $\pm91$
 2004 B
CBAR 0 ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \gamma}}$
$101.0$ $\pm8.8$ $\pm8.8$ 547
 2004 J
BES2 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
• • • We do not use the following data for averages, fits, limits, etc. • • •
$174$ $\pm44$
 1990
DM2 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \gamma}}{{\mathit \gamma}}$
$90$ $\pm26$ 1
 1990
MRK3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$2 ${{\mathit \gamma}}$
1  This peak in the ${{\mathit \gamma}}{{\mathit \rho}}$ channel may not be related to the ${{\mathit \eta}{(1405)}}$.
References:
 AMSLER 2004B
EPJ C33 23 Production and Decay of ${{\mathit \eta}^{\,'}{(958)}}$ and ${{\mathit \eta}{(1440)}}$ in ${{\overline{\mathit p}}}{{\mathit p}}$ Annihilation at Rest
 BAI 2004J
PL B594 47 A Study of ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$ $\mathit V({{\mathit \rho}},{{\mathit \phi}}$) Decays with the BESII Detector
 AUGUSTIN 1990
PR D42 10 Radiative Decay of ${{\mathit J / \psi}}$ into ${{\mathit \eta}{(1430)}}$ and Nearby States
 COFFMAN 1990
PR D41 1410 Study of the Doubly Radiative Decay ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \rho}^{0}}$