# PARAMETERS FOR ${{\boldsymbol \eta}}$ $\rightarrow$ ${{\boldsymbol \pi}^{+}}{{\boldsymbol \pi}^{-}}{{\boldsymbol \pi}^{0}}$ INSPIRE search

See the Note on ${{\mathit \eta}}$ Decay Parameters,'' page 1454, in our 1994 edition (Physical Review D50 1173 (1994)). The following experiments fit to one or more of the coefficients $\mathit a$, $\mathit b$, $\mathit c$, $\mathit d$, $\mathit e$, $\mathit f$ or $\mathit g$ for $\vert$matrix element$\vert ^2$ = 1 + $\mathit a{}\mathit y$ + $\mathit b{}\mathit y{}^{2}$ + $\mathit c{}\mathit x$ + $\mathit d{}\mathit x{}^{2}$ + $\mathit e{}\mathit x{}\mathit y$ + $\mathit f{}\mathit y{}^{3}$ + $\mathit g{}\mathit x{}^{2}{}\mathit y$.
VALUE EVTS DOCUMENT ID TECN  COMMENT
• • • We do not use the following data for averages, fits, limits, etc. • • •
4.7M 1
 2016 A
KLOE ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \phi}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \gamma}}$
79k
 2015 G
BES3 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}}$
174k
 2014 A
WASA ${{\mathit p}}$ ${{\mathit d}}$ $\rightarrow$ ${{\mathit \eta}}$ ${}^{3}\mathrm {He}$
1.34M
 2008 D
KLOE
3230 2
 1998 D
CBAR ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit \eta}}$ at rest
1077 3
 1995
CBAR ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \eta}}$ at rest
81k
 1973
ASPK
220k
 1972
ASPK
1138
 1970
HBC
349
 1970
DBC
7250
 1970
WIRE
526
 1969
HLBC
7170
 1968
OSPK
37k
 1968 C
WIRE
1300
 1966
HBC
705
 1966
HBC
1  ANASTASI 2016A measure the Dalitz parameters $\mathit a$, $\mathit b$, $\mathit d$, $\mathit f$, and $\mathit g$. This is the first measurement of $\mathit g$.
2  ABELE 1998D obtains $\mathit a$ =$-1.22$ $\pm0.07$ and $\mathit b$ = $0.22$ $\pm0.11$ when $\mathit c$ (or$~\mathit d$) is fixed at $0.06$.
3  AMSLER 1995 fits to (1$+\mathit ay+\mathit by{}^{2}$) and obtains $\mathit a=-0.94$ $\pm0.15$ and $\mathit b=0.11$ $\pm0.27$.
References:
 ANASTASI 2016A
JHEP 1605 019 Precision Measurement of the ${{\mathit \eta}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ Dalitz Plot Distribution with the KLOE Detector
 ABLIKIM 2015G
PR D92 012014 Measurement of the Matrix Elements for the Decays ${{\mathit \eta}}$ $\rightarrow$ ${+}$ ${{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ and ${{\mathit \eta}}$ $/$ ${{\mathit \eta}^{\,'}}$ $\rightarrow$ ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$
PR C90 045207 Measurement of the ${{\mathit \eta}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ Dalitz Plot Distribution
 AMBROSINO 2008D
JHEP 0805 006 Determination of ${{\mathit \eta}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ Dalitz Plot Slopes and Asymmetries with the KLOE Detector
 ABELE 1998D
PL B417 197 Momentum Dependence of the Decay ${{\mathit \eta}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$
 AMSLER 1995
PL B346 203 ${{\mathit \eta}}$-Decays into Three Pion
 LAYTER 1973
PR D7 2565 Study of Dalitz Plot Distributions of the Decays ${{\mathit \eta}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ and ${{\mathit \eta}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \gamma}}$
 LAYTER 1972
PRL 29 316 Measurement of the Charge Asymmetry in the Decay ${{\mathit \eta}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$
 CARPENTER 1970
PR D1 1303 ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ Decay of 1138 ${{\mathit \eta}}$ Mesons Produced in ${{\mathit K}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \eta}}$ near Threshold
 DANBURG 1970
PR D2 2564 Production and Decay of ${{\mathit \eta}}$ and ${{\mathit \omega}}$ Mesons in the Reaction ${{\mathit \pi}^{+}}$ ${{\mathit d}}$ $\rightarrow$ ( ${{\mathit p}}$) ${{\mathit p}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ between 1.1 and 2.4 ${\mathrm {GeV/}}\mathit c$
 GORMLEY 1970
PR D2 501 Experimental Determination of the Dalitz-Plot Distribution of the Decays ${{\mathit \eta}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ and ${{\mathit \eta}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \gamma}}$ , and the Branching ratio ${{\mathit \eta}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \gamma}}$ $/$ ${{\mathit \eta}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$
 BAGLIN 1969
PL 29B 445 Heavy Liquid Chamber Analysis of ${{\mathit \eta}}$ $\rightarrow$ 3 ${{\mathit \pi}}$ and ${{\mathit \eta}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$ Decay Modes
 CNOPS 1968
PRL 21 1609 Coherent Production of ${{\mathit \pi}^{+}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ in Deuterium by 8 ${\mathrm {GeV/}}\mathit c$ ${{\mathit \pi}^{+}}$
 GORMLEY 1968C
PRL 21 402 Experimental Test of $\mathit C$ Invariance in ${{\mathit \eta}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$
 CLPWY 1966
PR 149 1044 Search for $\mathit C$ Violation in ${{\mathit \eta}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ (CLPWY: Columbia-Berkeley-Purdue-Wisconsin-Yale Collaboration)
 LARRIBE 1966
PL 23 600 Test of $\mathit C$ Invariance in the 3${{\mathit \pi}}$ Decay Mode of the ${{\mathit \eta}}$ Meson