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 search

#### ${{\boldsymbol X}{(1835)}}$

$I^G(J^{PC})$ = $?^?(0^{- +})$
Could be a superposition of two states, one with small width appearing as threshold enhancement in ${{\mathit p}}{{\overline{\mathit p}}}$ , the other one with a larger width. For the former ABLIKIM 2012D determine $\mathit J{}^{PC} = 0{}^{-+}$.
 ${{\mathit X}{(1835)}}$ MASS $1826.5 {}^{+13.0}_{-3.4}$ MeV
 ${{\mathit X}{(1835)}}$ WIDTH $242 {}^{+14}_{-15}$ MeV
 $\Gamma_{1}$ ${{\mathit p}}{{\overline{\mathit p}}}$ seen -1
 $\Gamma_{2}$ ${{\mathit \eta}^{\,'}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ seen 624
 $\Gamma_{3}$ ${{\mathit \gamma}}{{\mathit \gamma}}$ 913
 $\Gamma_{4}$ ${{\mathit K}_S^0}$ ${{\mathit K}_S^0}$ ${{\mathit \eta}}$ seen 474
 $\Gamma_{5}$ ${{\mathit \gamma}}{{\mathit \phi}{(1020)}}$ possibly seen 629
 $\Gamma_{6}$ 3 ( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$) seen 773
 FOOTNOTES