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LIGHT UNFLAVORED MESONS
($\boldsymbol S$ = $\boldsymbol C$ = $\boldsymbol B$ = 0)
For $\mathit I = 1$ (${{\mathit \pi}}$, ${{\mathit b}}$, ${{\mathit \rho}}$, ${{\mathit a}}$): ${\mathit {\mathit u}}$ ${\mathit {\overline{\mathit d}}}$, ( ${\mathit {\mathit u}}$ ${\mathit {\overline{\mathit u}}}−$ ${\mathit {\mathit d}}$ ${\mathit {\overline{\mathit d}}})/\sqrt {2 }$, ${\mathit {\mathit d}}$ ${\mathit {\overline{\mathit u}}}$;
for $\mathit I = 0$ (${{\mathit \eta}}$, ${{\mathit \eta}^{\,'}}$, ${{\mathit h}}$, ${{\mathit h}^{\,'}}$, ${{\mathit \omega}}$, ${{\mathit \phi}}$, ${{\mathit f}}$, ${{\mathit f}^{\,'}}$): ${\mathit {\mathit c}}_{{\mathrm {1}}}$( ${{\mathit u}}{{\overline{\mathit u}}}$ $+$ ${{\mathit d}}{{\overline{\mathit d}}}$ ) $+$ ${\mathit {\mathit c}}_{{\mathrm {2}}}$( ${{\mathit s}}{{\overline{\mathit s}}}$ )

${{\boldsymbol \eta}^{\,'}{(958)}}$ $I^G(J^{PC})$ = $0^+(0^{- +})$

${{\mathit \eta}^{\,'}{(958)}}$ MASS

$957.78 \pm0.06$ MeV

${{\mathit \eta}^{\,'}{(958)}}$ WIDTH

$0.188 \pm0.006$ MeV

${{\boldsymbol \eta}^{\,'}{(958)}}$ $\rightarrow$ ${{\boldsymbol \eta}}{{\boldsymbol \pi}}{{\boldsymbol \pi}}$ DECAY PARAMETERS $\vert $MATRIX ELEMENT$\vert ^2$ = $\vert $1 + $\alpha {}\boldsymbol Y\vert ^2$ + $\boldsymbol C{}\boldsymbol X$ + $\boldsymbol D{}\boldsymbol X{}^{2}$

$\mathit Re(\alpha $) decay parameter

$\mathit Im(\alpha $) decay parameter

$\mathit C$ decay parameter

$\mathit D$ decay parameter

${{\boldsymbol \eta}^{\,'}{(958)}}$ $\rightarrow$ ${{\boldsymbol \eta}}{{\boldsymbol \pi}}{{\boldsymbol \pi}}$ DECAY PARAMETERS $\vert $MATRIX ELEMENT$\vert ^2$ ${}\propto$ 1 + $\boldsymbol a~Y$ + $\boldsymbol b~Y{}^{2}$ + $\boldsymbol c~X$ + $\boldsymbol d~X{}^{2}$

$\mathit a$ decay parameter

$\mathit b$ decay parameter

$\mathit c$ decay parameter

$\mathit d$ decay parameter

${{\boldsymbol \eta}^{\,'}{(958)}}$ $\beta $ PARAMETER $\vert $MATRIX ELEMENT$\vert ^2$ = (1 + 2$\beta {{\boldsymbol Z}}$)

$\beta $ decay parameter

$-0.61 \pm0.08$ (S = 1.2)

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

DECAY ASYMMETRY PARAMETER FOR ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \gamma}}$

$-0.03 \pm0.04$

${{\mathit \eta}^{\,'}{(958)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ TRANSITION FORM FACTOR SLOPE

$1.62 \pm0.17$ GeV${}^{-2}$

Decay Modes ▸ Expand all decays

${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \eta}}$

$(42.5\pm{0.5})\%$

${{\mathit \rho}^{0}}{{\mathit \gamma}}$ (including non-resonant ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \gamma}}$)

$(29.5\pm{0.4})\%$

${{\mathit \rho}^{0}}{{\mathit \gamma}}$

${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit \eta}}$

$(22.4\pm{0.5})\%$

${{\mathit \omega}}{{\mathit \gamma}}$

$(2.52\pm{0.07})\%$

${{\mathit \omega}}{{\mathit e}^{+}}{{\mathit e}^{-}}$

$(2.0\pm{0.4})\times 10^{-4}$

${{\mathit \gamma}}{{\mathit \gamma}}$

$(2.307\pm{0.033})\%$

3 ${{\mathit \pi}^{0}}$

$(2.50\pm{0.17})\times 10^{-3}$

${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}{{\mathit \gamma}}$

$(1.13\pm{0.28})\times 10^{-4}$

${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$

$<2.9\times 10^{-5}$

${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$

$(3.61\pm{0.17})\times 10^{-3}$

( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$) S-wave

$(3.8\pm{0.5})\times 10^{-3}$

${{\mathit \pi}^{\mp}}{{\mathit \rho}^{\pm}}$

$(7.4\pm{2.3})\times 10^{-4}$

${{\mathit \pi}^{0}}{{\mathit \rho}^{0}}$

2( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$)

$(8.4\pm{0.9})\times 10^{-5}$

${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$2 ${{\mathit \pi}^{0}}$

$(1.8\pm{0.4})\times 10^{-4}$

2( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$) neutrals

2( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$) ${{\mathit \pi}^{0}}$

$<1.8\times 10^{-3}$

2( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$) 2 ${{\mathit \pi}^{0}}$

3( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$)

$<3.1\times 10^{-5}$

${{\mathit K}^{\pm}}{{\mathit \pi}^{\mp}}$

$<4\times 10^{-5}$

${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit e}^{+}}{{\mathit e}^{-}}$

$(2.4^{+1.3}_{-1.0})\times 10^{-3}$

${{\mathit \pi}^{+}}{{\mathit e}^{-}}{{\mathit \nu}_{{e}}}$ + c.c.

$<2.1\times 10^{-4}$

${{\mathit \gamma}}{{\mathit e}^{+}}{{\mathit e}^{-}}$

$(4.91\pm{0.27})\times 10^{-4}$

${{\mathit \pi}^{0}}{{\mathit \gamma}}{{\mathit \gamma}}$

$(3.20\pm{0.24})\times 10^{-3}$

${{\mathit \pi}^{0}}{{\mathit \gamma}}{{\mathit \gamma}}$ (non resonant)

$(6.2\pm{0.9})\times 10^{-4}$

${{\mathit \eta}}{{\mathit \gamma}}{{\mathit \gamma}}$

$<1.33\times 10^{-4}$

4 ${{\mathit \pi}^{0}}$

$<3.2\times 10^{-4}$

${{\mathit e}^{+}}{{\mathit e}^{-}}$

$<5.6\times 10^{-9}$

$<6\times 10^{-4}$

▸	Charge conjugation ($\mathit C$), Parity ($\mathit P$), Lepton family number ($\mathit LF$) violating modes

constrained fit information