# ${{\boldsymbol \eta}^{\,'}{(958)}}{}^{C}$-NONCONSERVING DECAY PARAMETER

See the note on ${{\mathit \eta}}$ decay parameters in the Stable Particle Particle Listings for definition of this parameter.

# DECAY ASYMMETRY PARAMETER FOR ${{\boldsymbol \pi}^{+}}{{\boldsymbol \pi}^{-}}{{\boldsymbol \gamma}}$ INSPIRE search

VALUE EVTS DOCUMENT ID TECN  COMMENT
$\bf{ -0.03 \pm0.04}$ OUR AVERAGE
$-0.019$ $\pm0.056$
 1987
TPC ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \gamma}}$
$-0.069$ $\pm0.078$ 295
 1975
STRC 2.1 ${{\mathit \pi}^{-}}{{\mathit p}}$
$0.00$ $\pm0.10$ 103
 1975
HBC 2.18 ${{\mathit K}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \gamma}}$
• • • We do not use the following data for averages, fits, limits, etc. • • •
$0.07$ $\pm0.08$ 152
 1965
HBC 2.1$-$2.7 ${{\mathit K}^{-}}{{\mathit p}}$
Conservation Laws:
 CHARGE CONJUGATION ($\mathit C$) INVARIANCE
References:
 AIHARA 1987
PR D35 2650 Study of ${{\mathit \eta}^{\,'}{(958)}}$ Formation in Photon Photon Collisions
 GRIGORIAN 1975
NP B91 232 Charge Conjugation Invariance in ${{\mathit \eta}^{\,'}{(958)}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \gamma}}$
 KALBFLEISCH 1975
PR D11 987 Single ${{\mathit \gamma}}$ Decays of ${{\mathit \eta}^{\,'}{(958)}}$, ${{\mathit \omega}{(783)}}$, ${{\mathit \phi}{(1019)}}$ and ${{\mathit \Xi}^{*}{(1535)}^{-}}$
 RITTENBERG 1965
PRL 15 556 Search for $\mathit C$ Invariance Violation in ${{\mathit \eta}}$ (958 MeV) and ${{\mathit \eta}}$ (549 MeV) Decays