# ${{\boldsymbol \eta}^{\,'}{(958)}}$ MASS INSPIRE search

VALUE (MeV) EVTS DOCUMENT ID TECN  COMMENT
$\bf{ 957.78 \pm0.06}$ OUR AVERAGE
$957.793$ $\pm0.054$ $\pm0.036$ 3.9k
 2008
CLEO ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}^{\,'}}$
$957.9$ $\pm0.2$ $\pm0.6$ 4800
 1996
SPEC 1.68 ${{\mathit p}}$ ${{\mathit d}}$ $\rightarrow$ ${}^{3}\mathrm {He}$ ${{\mathit \eta}^{\,'}}$
$957.46$ $\pm0.33$
 1974
MMS ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit n}}$ MM
$958.2$ $\pm0.5$ 1414
 1973
HBC 2.2 ${{\mathit K}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \eta}^{\,'}}$
$958$ $\pm1$ 400
 1973
HBC 2.9 ${{\mathit K}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \eta}^{\,'}}$
$956.1$ $\pm1.1$ 3415 1
 1971
CNTR 1.6 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit n}}{{\mathit \eta}^{\,'}}$
• • • We do not use the following data for averages, fits, limits, etc. • • •
$957.5$ $\pm0.2$
 2004 J
BES2 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
$959$ $\pm1$ $630$ 2
 1992 C
VES 36 ${{\mathit \pi}^{-}}$ ${}^{}\mathrm {Be}$ ${{\mathit \pi}^{-}}$ ${{\mathit \eta}^{\,'}}$ ${{\mathit \eta}}$ ${}^{}\mathrm {Be}$
$958$ $\pm1$ 340 2
 1991 B
OMEG 300 ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit p}}{{\mathit p}}{{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
$958.2$ $\pm0.4$ 622 2
 1990
DM2 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
$957.8$ $\pm0.2$ 2420 2
 1990
DM2 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
$956.3$ $\pm1.0$ $143$ 2
 1987
MRK2 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
$957.4$ $\pm1.4$ 535 3
 1971
CNTR 1.6 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit n}}{{\mathit \eta}^{\,'}}$
$957$ $\pm1$
 1969
HBC 1.7$-$2.7 ${{\mathit K}^{-}}{{\mathit p}}$
1  Using all ${{\mathit \eta}^{\,'}}$ decays.
2  Systematic uncertainty not estimated.
3  Using ${{\mathit \eta}^{\,'}}$ decays into neutrals. Not independent of the other listed BASILE 1971 ${{\mathit \eta}^{\,'}}$ mass measurement.
References:
 LIBBY 2008
PRL 101 182002 Measurement of the ${{\mathit \eta}^{\,'}}$-Meson Mass using ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}^{\,'}}$
 BAI 2004J
PL B594 47 A Study of ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$ $\mathit V({{\mathit \rho}},{{\mathit \phi}}$) Decays with the BESII Detector
 WURZINGER 1996
PL B374 283 Observation of ${{\mathit \eta}^{\,'}{(958)}}$ and ${{\mathit \phi}{(1020)}}$ Meson Production very Close to Threshold in the ${{\mathit p}}$ ${{\mathit d}}$ $\rightarrow$ ${}^{3}\mathrm {He}$ ${{\mathit X}}$ Reaction
SJNP 55 1535 Study of the Process ${{\mathit \pi}^{-}}$ ${{\mathit A}}$ $\rightarrow$ ${{\mathit \pi}^{-}}{{\mathit \eta}^{\,'}}{{\mathit \eta}}{{\mathit A}}$ at 36 ${\mathrm {GeV/}}\mathit c$
 ARMSTRONG 1991B
ZPHY C52 389 Study of the ${{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ System Centrally Produced in the Reaction ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit p}_{{f}}}$( ${{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$) ${{\mathit p}_{{s}}}$ at 300 ${\mathrm {GeV/}}\mathit c$
 AUGUSTIN 1990
PR D42 10 Radiative Decay of ${{\mathit J / \psi}}$ into ${{\mathit \eta}{(1430)}}$ and Nearby States
 GIDAL 1987
PRL 59 2012 Observation of Spin 1 ${{\mathit f}_{{1}}{(1285)}}$ in the Reaction ${{\mathit \gamma}}$ ${{\mathit \gamma}^{*}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
 DUANE 1974
PRL 32 425 New Upper Limit on the Width of the ${{\mathit X}{(958)}^{0}}$
 DANBURG 1973
PR D8 3744 Study of the ${{\mathit \eta}^{\,'}{(958)}}$ Meson from the Reaction ${{\mathit K}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \eta}^{\,'}{(958)}}$ at 2.18 ${\mathrm {GeV/}}\mathit c$
 JACOBS 1973
PR D8 18 Study of the ${{\mathit \eta}^{\,'}{(958)}}$ Produced in ${{\mathit K}^{-}}{{\mathit p}}$ Interactions at 2.885 ${\mathrm {GeV/}}\mathit c$
 BASILE 1971
NC 3A 371 Measurement of the ${{\mathit m}{(953)}}$ Cross Sections in ${{\mathit \pi}^{-}}{{\mathit p}}$ Interactions at 1.6 ${\mathrm {GeV/}}\mathit c$ and Determination of the Branching Ratio ( ${{\mathit m}{(953)}}$ $\rightarrow$ neutrals)/( ${{\mathit m}{(953)}}$ $\rightarrow$ total)
 RITTENBERG 1969
Thesis UCRL 18863 Properties of the ${{\mathit \eta}^{\,'}{(958)}}$ Meson