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:
M010

${{\mathit a}_{{{1}}}{(1260)}}$

$I^G(J^{PC})$ = $1^-(1^{+ +})$ 
See also our review under the ${{\mathit a}_{{{1}}}{(1260)}}$ in PDG 2006, Journal of Physics G33 1 (2006).
${{\mathit a}_{{{1}}}{(1260)}}$ T-MATRIX POLE $\sqrt {\mathit s }$ (1209+13-10)-i(288+45-12) MeV 
 
${{\mathit a}_{{{1}}}{(1260)}}$ MASS [1] $1230$ $\pm40$ MeV 
 
${{\mathit a}_{{{1}}}{(1260)}}$ WIDTH [1] $380$ $\pm80$ MeV 
 
${\mathit D}{\mathrm -wave}/{\mathit S}{\mathrm -wave}$ AMPLITUDE RATIO IN DECAY OF ${{\mathit a}_{{{1}}}{(1260)}}$ $\rightarrow$ ${{\mathit \rho}}{{\mathit \pi}}$ $-0.062$ $\pm0.020$  (S = 2.3)
 
Mode  
Fraction ($\Gamma_i$ / $\Gamma$) Scale Factor/
Conf. Level		 P(MeV/c)  
$\Gamma_{1}$ 3 ${{\mathit \pi}}$ seen 577
 
$\Gamma_{2}$ ( ${{\mathit \rho}}{{\mathit \pi}}$) $_{\mathit S{\mathrm {-wave}}}$ , ${{\mathit \rho}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit \pi}}$ seen 353
 
$\Gamma_{3}$ ( ${{\mathit \rho}}{{\mathit \pi}}$) $_{\mathit D{\mathrm {-wave}}}$ , ${{\mathit \rho}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit \pi}}$ seen 353
 
$\Gamma_{4}$ ( ${{\mathit \rho}{(1450)}}{{\mathit \pi}}$) $_{\mathit S{\mathrm {-wave}}}$ , ${{\mathit \rho}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit \pi}}$ seen -1
 
$\Gamma_{5}$ ( ${{\mathit \rho}{(1450)}}{{\mathit \pi}}$) $_{\mathit D{\mathrm {-wave}}}$ , ${{\mathit \rho}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit \pi}}$ seen -1
 
$\Gamma_{6}$ ${{\mathit f}_{{{0}}}{(500)}}{{\mathit \pi}}$ , ${{\mathit f}_{{{0}}}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit \pi}}$ seen  
 
$\Gamma_{7}$ ${{\mathit f}_{{{0}}}{(980)}}{{\mathit \pi}}$ , ${{\mathit f}_{{{0}}}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit \pi}}$ seen 179
 
$\Gamma_{8}$ ${{\mathit f}_{{{0}}}{(1370)}}{{\mathit \pi}}$ , ${{\mathit f}_{{{0}}}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit \pi}}$ seen -1
 
$\Gamma_{9}$ ${{\mathit f}_{{{2}}}{(1270)}}{{\mathit \pi}}$ , ${{\mathit f}_{{{2}}}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit \pi}}$ seen -1
 
$\Gamma_{10}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ seen 576
 
$\Gamma_{11}$ ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$ not seen 577
 
$\Gamma_{12}$ ${{\mathit K}}{{\mathit K}}{{\mathit \pi}}$ seen 250
 
$\Gamma_{13}$ ${{\mathit K}^{*}{(892)}}{{\mathit K}}$ seen -1
 
$\Gamma_{14}$ ${{\mathit \pi}}{{\mathit \gamma}}$ seen 608
 
[1] Our estimate. See the Particle Listings for details.