#### ${\boldsymbol m}_{{{\boldsymbol \psi}{(2S)}}}–{\boldsymbol m}_{{{\boldsymbol J / \psi}{(1S)}}}$

VALUE (MeV) DOCUMENT ID TECN  COMMENT
 $\bf{ 589.188 \pm0.028}$ OUR AVERAGE
$589.194$ $\pm0.027$ $\pm0.011$ 1
 2003
KEDR ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ hadrons
$589.7$ $\pm1.2$
 1982
GOLI 185 ${{\mathit \pi}^{-}}$ ${}^{}\mathrm {Be}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \mu}^{+}}{{\mathit \mu}^{-}}{}^{}\mathrm {A}$
$589.07$ $\pm0.13$ 1
 1980
OLYA ${{\mathit e}^{+}}{{\mathit e}^{-}}$
$588.7$ $\pm0.8$
 1975
MRK1
• • We do not use the following data for averages, fits, limits, etc. • •
$588$ $\pm1$ 2
 1998 E
BES ${{\mathit e}^{+}}{{\mathit e}^{-}}$
 1 Redundant with data in mass above.
 2 Systematic errors not evaluated.
References:
 AULCHENKO 2003
PL B573 63 New Precision Measurement of the ${{\mathit J / \psi}}$ and ${{\mathit \psi}^{\,'}}$ Meson Masses
 BAI 1998E
PR D57 3854 Search for ${{\mathit \psi}{(2S)}}$ Production in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Annihilations at 4.03 GeV
 LEMOIGNE 1982
PL 113B 509 Measurement of Hadronic Production of the ${{\mathit \chi}_{{1}}{(3507)}^{++}}$ and ${{\mathit \chi}_{{2}}{(3553)}^{++}}$ through Their Radiative Decay to ${{\mathit J / \psi}}$
 ZHOLENTZ 1980
PL 96B 214 High Precision Measurement of the ${{\mathit \psi}}$ and ${{\mathit \psi}^{\,'}}$ Meson Masses
 LUTH 1975
PRL 35 1124 The Quantum Numbers and Decay Widths of the ${{\mathit \psi}^{\,'}{(3684)}}$