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:
M161

${{\mathit a}_{{{1}}}{(1640)}}$

$I^G(J^{PC})$ = $1^-(1^{+ +})$ 
Possibly seen in the study of the hadronic structure in decay ${{\mathit \tau}}$ $\rightarrow$ 3 ${{\mathit \pi}}{{\mathit \nu}_{{{\tau}}}}$ (ABREU 1998G and ASNER 2000).
${{\mathit a}_{{{1}}}{(1640)}}$ MASS $1655$ $\pm16$ MeV (S = 1.2)
 
${{\mathit a}_{{{1}}}{(1640)}}$ WIDTH $250$ $\pm40$ MeV (S = 1.8)
 
Mode  
Fraction ($\Gamma_i$ / $\Gamma$) Scale Factor/
Conf. Level		 P(MeV/c)  
$\Gamma_{1}$ ${{\mathit \pi}}{{\mathit \pi}}{{\mathit \pi}}$ seen 800
 
$\Gamma_{2}$ ${{\mathit f}_{{{2}}}{(1270)}}{{\mathit \pi}}$ seen 314
 
$\Gamma_{3}$ ${{\mathit \sigma}}{{\mathit \pi}}$ seen  
 
$\Gamma_{4}$ ${{\mathit \rho}}{{\mathit \pi}}$ $_{{\mathit S}{\mathrm -wave}}$ seen 638
 
$\Gamma_{5}$ ${{\mathit \rho}}{{\mathit \pi}}$ $_{{\mathit D}{\mathrm -wave}}$ seen 638
 
$\Gamma_{6}$ ${{\mathit \omega}}{{\mathit \pi}}{{\mathit \pi}}$ seen 607
 
$\Gamma_{7}$ ${{\mathit f}_{{{1}}}{(1285)}}{{\mathit \pi}}$ seen 309
 
$\Gamma_{8}$ ${{\mathit a}_{{{1}}}{(1260)}}{{\mathit \eta}}$ not seen -1