#### ${{\mathit X}{(1750)}}$ MASS

VALUE (MeV) DOCUMENT ID TECN  COMMENT
 $\bf{ 1753.8 \pm2.7}$ OUR AVERAGE
$1784$ $\pm12$ ${}^{+0}_{-27}$
 2020 F
BES3 ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit \eta}}$
$1753.5$ $\pm1.5$ $\pm2.3$
 2002 K
FOCS $20 - 160$ ${{\mathit \gamma}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit p}}$
• • We do not use the following data for averages, fits, limits, etc. • •
$1726$ $\pm22$
 1989
TPS ${{\mathit \gamma}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit K}^{-}}$ X
$1760$ $\pm20$
 1985 C
OMEG 20$-$70 ${{\mathit \gamma}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit K}}{{\overline{\mathit K}}}$ X
$1690$ $\pm10$
 1981 F
OMEG 25$-$70 ${{\mathit \gamma}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit K}^{-}}$ X
References:
 ABLIKIM 2020F
PR D101 032008 Partial wave analysis of $\psi(3686)\to K^{+}K^{-}\eta$
PL B545 50 Observation of a 1750-MeV/$\mathit c{}^{2}$ Enhancement in the Diffractive Photoproduction of ${{\mathit K}^{+}}$ ${{\mathit K}^{-}}$
PR D40 1 High Energy Photoproduction of ${{\mathit \pi}^{+}}$ ${{\mathit \pi}^{-}}$ ${{\mathit \pi}^{0}}$ , ${{\mathit K}^{+}}$ ${{\mathit K}^{-}}$ , and ${{\mathit p}}$ ${{\overline{\mathit p}}}$ States
ZPHY C27 233 Photoproduction of ${{\mathit \Xi}}$ Mesons by Linearly Polarized Photons of Energy 20-40 GeV and Further Evidence for a Photoproduced High Mass (${{\mathit K}}$ ${{\overline{\mathit K}}}$ ) Enhancement
PL 104B 231 Evidence for a High Mass Enhancement in ${{\mathit K}^{+}}$ ${{\mathit K}^{-}}$ Photoproduction