${{\boldsymbol \eta}^{\,'}{(958)}}$ $\rightarrow$ ${{\boldsymbol \eta}}{{\boldsymbol \pi}}{{\boldsymbol \pi}}$ DECAY PARAMETERS
$\vert $MATRIX ELEMENT$\vert ^2$ ${}\propto$ 1 + $\boldsymbol a~Y$ + $\boldsymbol b~Y{}^{2}$ + $\boldsymbol c~X$ + $\boldsymbol d~X{}^{2}$
$\mathit X$ and $\mathit Y$ are Dalitz variables and $\mathit a,~b,~c$, and $\mathit d$ are real-valued parameters. May be different for ${{\mathit \eta}^{\,'}{(958)}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ and ${{\mathit \eta}^{\,'}{(958)}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$ decays. We do not average measurements in the section below because parameter values from each experiment are strongly correlated.
$\boldsymbol b$ decay parameter
INSPIRE search
• • • We do not use the following data for averages, fits, limits, etc. • • • |
$-0.049$ $\pm0.006$ $\pm0.006$ |
351k |
|
|
BES3 |
$-0.073$ $\pm0.014$ $\pm0.005$ |
56k |
|
|
BES3 |
$-0.063$ $\pm0.014$ $\pm0.005$ |
124k |
|
|
A2MM |
$-0.052$ $\pm0.001$ $\pm0.002$ |
|
1 |
|
RVUE |
$-0.069$ $\pm0.019$ $\pm0.009$ |
44k |
2 |
|
BES3 |
$-0.063$ $\pm0.028$ $\pm0.004$ |
15k |
3 |
|
GAM4 |
$-0.106$ $\pm0.028$ $\pm0.014$ |
20k |
4 |
|
VES |
1
Theoretical analysis of ADLARSON 2018A using resonance chiral perturbation theory to one loop.
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2
See ABLIKIM 2011 for the full correlation matrix.
|
3
From ${{\mathit \eta}^{\,'}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$ decay.
|
4
From ${{\mathit \eta}^{\,'}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ decay.
|
|
References: |
| PR D97 012003 |
Measurement of the Matrix Elements for the Decays ${{\mathit \eta}^{\,'}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ and ${{\mathit \eta}^{\,'}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$ |
| PR D98 012001 |
Measurement of the decay $\eta^{\prime}\to\pi^{0}\pi^{0}\eta$ at MAMI |
| EPJ C78 758 |
$\eta ^{\prime }\rightarrow \eta \pi \pi $ decays in unitarized resonance chiral theory |
| PR D83 012003 |
Measurement of the Matrix Element for the Decay ${{\mathit \eta}^{\,'}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ |
| PAN 72 231 |
Measurement of the Matrix Element for the Decay ${{\mathit \eta}^{\,'}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$ with the GAMS-4$\pi $ Spectrometer |
| PL B651 22 |
Study of ${{\mathit \eta}^{\,'}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ Dalitz Plot |
|