LIGHT UNFLAVORED MESONS
($\mathit S$ = $\mathit C$ = $\mathit B$ = 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 $\mathit I = 0$ (${{\mathit \eta}}$, ${{\mathit \eta}^{\,'}}$, ${{\mathit h}}$, ${{\mathit h}^{\,'}}$, ${{\mathit \omega}}$, ${{\mathit \phi}}$, ${{\mathit f}}$, ${{\mathit f}^{\,'}}$): ${\mathit {\mathit c}}_{{\mathrm {1}}}({{\mathit u}}{{\overline{\mathit u}}}$ $+$ ${{\mathit d}}{{\overline{\mathit d}}}$) $+$ ${\mathit {\mathit c}}_{{\mathrm {2}}}({{\mathit s}}{{\overline{\mathit s}}}$) 		INSPIRE   JSON PDGID:
M002

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

$I^G(J^{PC})$ = $0^+(0^{- +})$ 
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${{\mathit \eta}^{\,'}{(958)}}$ MASS $957.78$ $\pm0.06$ MeV 
 
${{\mathit \eta}^{\,'}{(958)}}$ WIDTH $0.188$ $\pm0.006$ MeV 
 
▸  ${{\mathit \eta}^{\,'}{(958)}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}}{{\mathit \pi}}$ DECAY PARAMETERS $\vert $MATRIX ELEMENT$\vert ^2$ = $\vert $1 + $\alpha {}\mathit Y\vert ^2$ + $\mathit C{}\mathit X$ + $\mathit D{}\mathit X{}^{2}$
▸  ${{\mathit \eta}^{\,'}{(958)}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}}{{\mathit \pi}}$ DECAY PARAMETERS $\vert $MATRIX ELEMENT$\vert ^2$ ${}\propto$ 1 + $\mathit a~Y$ + $\mathit b~Y{}^{2}$ + $\mathit c~X$ + $\mathit d~X{}^{2}$
▸  ${{\mathit \eta}^{\,'}{(958)}}$ $\beta $ PARAMETER $\vert $MATRIX ELEMENT$\vert ^2$ = (1 + 2$\beta {{\mathit Z}}$)
▸  ${{\mathit \eta}^{\,'}{(958)}}{}^{C}$-NONCONSERVING DECAY PARAMETER
${{\mathit \eta}^{\,'}{(958)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ TRANSITION FORM FACTOR SLOPE $1.53$ $\pm0.04$ GeV${}^{-2}$ 
 
Mode  
Fraction ($\Gamma_i$ / $\Gamma$) Scale Factor/
Conf. Level		 P(MeV/c)  
$\Gamma_{1}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \eta}}$ ($42.5$ $\pm0.5$ ) $\%$ 232
 
$\Gamma_{2}$ ${{\mathit \rho}^{0}}{{\mathit \gamma}}$ (including non-resonant ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \gamma}}$) ($29.48$ $\pm0.35$ ) $\%$ 165
 
$\Gamma_{3}$ ${{\mathit \rho}^{0}}{{\mathit \gamma}}$ 165
 
$\Gamma_{4}$ ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit \eta}}$ ($22.4$ $\pm0.5$ ) $\%$ 239
 
$\Gamma_{5}$ ${{\mathit \omega}}{{\mathit \gamma}}$ ($2.52$ $\pm0.07$ ) $\%$ 159
 
$\Gamma_{6}$ ${{\mathit \omega}}{{\mathit e}^{+}}{{\mathit e}^{-}}$ ($2.0$ $\pm0.4$) $ \times 10^{-4}$ 159
 
$\Gamma_{7}$ ${{\mathit \gamma}}{{\mathit \gamma}}$ ($2.307$ $\pm0.033$ ) $\%$ 479
 
$\Gamma_{8}$ 3 ${{\mathit \pi}^{0}}$ ($2.50$ $\pm0.17$) $ \times 10^{-3}$ 430
 
$\Gamma_{9}$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}{{\mathit \gamma}}$ ($1.13$ $\pm0.28$) $ \times 10^{-4}$ 467
 
$\Gamma_{10}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ ($2.13$ $\pm0.13$) $ \times 10^{-5}$ 401
 
$\Gamma_{11}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ ($3.61$ $\pm0.17$) $ \times 10^{-3}$ 428
 
$\Gamma_{12}$ ( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$) S-wave ($3.8$ $\pm0.5$) $ \times 10^{-3}$ 428
 
$\Gamma_{13}$ ${{\mathit \pi}^{\mp}}{{\mathit \rho}^{\pm}}$ ($7.4$ $\pm2.3$) $ \times 10^{-4}$ 106
 
$\Gamma_{14}$ 2( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$) ($8.51$ $\pm0.33$) $ \times 10^{-5}$ 372
 
$\Gamma_{15}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$2 ${{\mathit \pi}^{0}}$ ($2.11$ $\pm0.15$) $ \times 10^{-4}$ 376
 
$\Gamma_{16}$ 2( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$) neutrals <1 $\%$ CL=95%  
 
$\Gamma_{17}$ 2( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$) ${{\mathit \pi}^{0}}$ $<1.8$ $\times 10^{-3}$ CL=90% 298
 
$\Gamma_{18}$ 2( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$) 2 ${{\mathit \pi}^{0}}$ <1 $\%$ CL=95% 197
 
$\Gamma_{19}$ 3( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$) $<3.1$ $\times 10^{-5}$ CL=90% 189
 
$\Gamma_{20}$ ${{\mathit K}^{\pm}}{{\mathit \pi}^{\mp}}$ $<4$ $\times 10^{-5}$ CL=90% 334
 
$\Gamma_{21}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit e}^{+}}{{\mathit e}^{-}}$ ($2.43$ $\pm0.06$) $ \times 10^{-3}$ 458
 
$\Gamma_{22}$ ${{\mathit \pi}^{+}}{{\mathit e}^{-}}{{\mathit \nu}_{{{e}}}}$ + c.c. $<2.1$ $\times 10^{-4}$ CL=90% 469
 
$\Gamma_{23}$ ${{\mathit \gamma}}{{\mathit e}^{+}}{{\mathit e}^{-}}$ ($4.80$ $\pm0.15$) $ \times 10^{-4}$ 479
 
$\Gamma_{24}$ ${{\mathit \pi}^{0}}{{\mathit \gamma}}{{\mathit \gamma}}$ ($3.20$ $\pm0.24$) $ \times 10^{-3}$ 469
 
$\Gamma_{25}$ ${{\mathit \pi}^{0}}{{\mathit \gamma}}{{\mathit \gamma}}$ (non resonant) ($6.2$ $\pm0.9$) $ \times 10^{-4}$  
 
$\Gamma_{26}$ ${{\mathit \eta}}{{\mathit \gamma}}{{\mathit \gamma}}$ $<1.33$ $\times 10^{-4}$ CL=90% 322
 
$\Gamma_{27}$ 4 ${{\mathit \pi}^{0}}$ $<1.2$ $\times 10^{-5}$ CL=90% 380
 
$\Gamma_{28}$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ $<5.6$ $\times 10^{-9}$ CL=90% 479
 
$\Gamma_{29}$ ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit e}^{+}}{{\mathit e}^{-}}$ ($4.5$ $\pm1.1$) $ \times 10^{-6}$ 479
 
$\Gamma_{30}$ invisible $<2.1$ $\times 10^{-4}$ CL=90%  
 
$\Gamma_{31}$ ${{\mathit \gamma}}$ Dark Photon (5.0)E-07 to 3.50 CL=90%  
 
▸  Charge conjugation ($\mathit C$), Parity ($\mathit P$), Lepton family number ($\mathit LF$) violating modes
[1] $\mathit C$ parity forbids this to occur as a single-photon process.
Constrained Fit information