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 $\mathit I = 0$ (${{\mathit \eta}}$, ${{\mathit \eta}^{\,'}}$, ${{\mathit h}}$, ${{\mathit h}^{\,'}}$, ${{\mathit \omega}}$, ${{\mathit \phi}}$, ${{\mathit f}}$, ${{\mathit f}^{\,'}}$): ${\mathit {\mathit c}}_{{\mathrm {1}}}$( ${{\mathit u}}{{\overline{\mathit u}}}$ $+$ ${{\mathit d}}{{\overline{\mathit d}}}$ ) $+$ ${\mathit {\mathit c}}_{{\mathrm {2}}}$( ${{\mathit s}}{{\overline{\mathit s}}}$ ) INSPIRE search

# ${{\boldsymbol \eta}{(1405)}}$ $I^G(J^{PC})$ = $0^+(0^{- +})$

See also the ${{\mathit \eta}{(1475)}}$.
 See related review: Pseudoscalar and Pseudovector Mesons in the 1400 MeV Region
${{\boldsymbol \eta}{(1405)}}$ MASS
 Mass $\mathit m$ $1408.8 \pm2.0$ MeV (S = 2.2)
 ${{\mathit \eta}}{{\mathit \pi}}{{\mathit \pi}}$ MODE $1405.8 \pm2.6$ MeV (S = 2.3)
 ${{\mathit K}}{{\overline{\mathit K}}}{{\mathit \pi}}$ MODE ( ${{\mathit a}_{{0}}{(980)}}{{\mathit \pi}}$ or direct ${{\mathit K}}{{\overline{\mathit K}}}{{\mathit \pi}}$ ) $1413.9 \pm1.7$ MeV (S = 1.1)
 ${{\mathit \pi}}{{\mathit \pi}}{{\mathit \gamma}}$ MODE $1403 \pm17$ MeV (S = 1.8)
 4 ${{\mathit \pi}}$ MODE
 ${{\mathit K}}{{\overline{\mathit K}}}{{\mathit \pi}}$ MODE (unresolved)
${{\boldsymbol \eta}{(1405)}}$ WIDTH
 Full width $\Gamma$ $50.1 \pm2.6$ MeV (S = 1.7)
 ${{\mathit \eta}}{{\mathit \pi}}{{\mathit \pi}}$ MODE $52.6 \pm3.2$ MeV (S = 1.3)
 ${{\mathit K}}{{\overline{\mathit K}}}{{\mathit \pi}}$ MODE ( ${{\mathit a}_{{0}}{(980)}}{{\mathit \pi}}$ or direct ${{\mathit K}}{{\overline{\mathit K}}}{{\mathit \pi}}$ ) $48 \pm4$ MeV (S = 2.1)
 ${{\mathit \pi}}{{\mathit \pi}}{{\mathit \gamma}}$ MODE $89 \pm17$ MeV (S = 1.7)
 4 ${{\mathit \pi}}$ MODE
 ${{\mathit K}}{{\overline{\mathit K}}}{{\mathit \pi}}$ MODE (unresolved)