#### ${{\boldsymbol X}{(4020)}^{\pm}}$ MASS

VALUE (MeV) EVTS DOCUMENT ID TECN CHG  COMMENT
 $\bf{ 4024.1 \pm1.9}$ OUR AVERAGE
$4025.5$ ${}^{+2.0}_{-4.7}$ $\pm3.1$ 116 1
 2015 AA
BES3 0 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ( ${{\mathit D}^{*}}{{\overline{\mathit D}}^{*}}$ )${}^{0}{{\mathit \pi}^{0}}$
$4026.3$ $\pm2.6$ $\pm3.7$ 401 1
 2014 B
BES3 $\pm{}$ ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ( ${{\mathit D}^{*}}{{\overline{\mathit D}}^{*}}$ )${}^{+-}{{\mathit \pi}^{\mp}}$
$4023.9$ $\pm2.2$ $\pm3.8$ 61 1, 2
 2014 P
BES3 0 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit h}_{{c}}}$
$4022.9$ $\pm0.8$ $\pm2.7$ 253 1
 2013 X
BES3 $\pm{}$ ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit h}_{{c}}}$
 1 Neglecting interference between the ${{\mathit X}{(4020)}}$ and non-resonant continuum.
 2 Assuming $\mathit J{}^{P} = 1{}^{+}$ and width of $7.9$ $\pm2.6$ MeV.
References:
 ABLIKIM 2015AA
PRL 115 182002 Observation of a Neutral Charmoniumlike State ${{\mathit Z}_{{c}}{(4025)}^{0}}$ in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ (${{\mathit D}^{*}}{{\overline{\mathit D}}^{*}}){}^{0}{{\mathit \pi}^{0}}$
 ABLIKIM 2014B
PRL 112 132001 Observation of a Charged Charmoniumlike Structure in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ( ${{\mathit D}^{*}}{{\overline{\mathit D}}^{*}}){}^{+-}{{\mathit \pi}^{\mp}}$ at $\sqrt {s }$ = 4.26 GeV
 ABLIKIM 2014P
PRL 113 212002 Observation of ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit h}_{{c}}}$ and a Neutral Charmoniumlike Structure ${{\mathit Z}_{{c}}{(4020)}^{0}}$
 ABLIKIM 2013X
PRL 111 242001 Observation of a Charged Charmoniumlike Structure ${{\mathit Z}_{{c}}{(4020)}}$ and Search for the ${{\mathit Z}_{{c}}{(3900)}}$ in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit h}_{{c}}}$