#### ${{\boldsymbol \eta}_{{c}}{(1S)}}$ WIDTH

VALUE (MeV) EVTS DOCUMENT ID TECN  COMMENT
 $\bf{ 32.0 \pm0.7}$ OUR FIT
 $\bf{ 32.1 \pm0.8}$ OUR AVERAGE  Error includes scale factor of 1.1.
$33.8$ $\pm1.6$ $\pm4.1$ 1705
 2019 AV
BES3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \omega}}{{\mathit \omega}}$
$30.8$ ${}^{+2.3}_{-2.2}$ $\pm2.9$ 2673
 2018
BELL ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit \eta}^{\,'}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
$34.0$ $\pm1.9$ $\pm1.3$ 11k
LHCB ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit B}^{+}}{{\mathit X}}$ $\rightarrow$ ${{\mathit p}}{{\overline{\mathit p}}}{{\mathit K}^{+}}{{\mathit X}}$
$31.4$ $\pm3.5$ $\pm2.0$ 6.4k 1
 2017 BB
LHCB ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit X}}$ $\rightarrow$ 2( ${{\mathit K}^{+}}{{\mathit K}^{-}}$) ${{\mathit X}}$
$27.2$ $\pm3.1$ ${}^{+5.4}_{-2.6}$ 2
 2014
KEDR ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}_{{c}}}$
$25.2$ $\pm2.6$ $\pm2.4$ 4.5k 3, 4
 2014 E
BABR ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit \pi}^{0}}$
$34.8$ $\pm3.1$ $\pm4.0$ 900 3, 5, 4
 2014 E
BABR ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit \eta}}$
$32.0$ $\pm1.2$ $\pm1.0$ 6, 7
 2012 F
BES3 ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}_{{c}}}$
$36.4$ $\pm3.2$ $\pm1.7$ 832 3
 2012 N
BES3 ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \pi}^{0}}{{\mathit \gamma}}$ hadrons
$37.8$ ${}^{+5.8}_{-5.3}$ $\pm3.1$ 486
 2012 A
BELL ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit \eta}^{\,'}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
$36.2$ $\pm2.8$ $\pm3.0$ 11k
 2011 M
BABR ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$
$35.1$ $\pm3.1$ ${}^{+1.0}_{-1.6}$ 920 7
 2011
BELL ${{\mathit B}^{\pm}}$ $\rightarrow$ ${{\mathit K}^{\pm}}$ ( ${{\mathit K}_S^0}$ ${{\mathit K}^{\pm}}{{\mathit \pi}^{\mp}}$ )
$31.7$ $\pm1.2$ $\pm0.8$ 14k 8
 2010
BABR 10.6 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit K}_S^0}$ ${{\mathit K}^{\pm}}{{\mathit \pi}^{\mp}}$
$36.3$ ${}^{+3.7}_{-3.6}$ $\pm4.4$ 0.9k
 2008 AB
BABR ${{\mathit B}}$ $\rightarrow$ ${{\mathit \eta}_{{c}}{(1S)}}{{\mathit K}^{(*)}}$ $\rightarrow$ ${{\mathit K}}{{\overline{\mathit K}}}{{\mathit \pi}}{{\mathit K}^{(*)}}$
$28.1$ $\pm3.2$ $\pm2.2$ 7.5k
 2008
BELL ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit \eta}_{{c}}}$ $\rightarrow$ hadrons
$48$ ${}^{+8}_{-7}$ $\pm5$ 195
 2006
BELL ${{\mathit B}^{+}}$ $\rightarrow$ ${{\mathit p}}{{\overline{\mathit p}}}{{\mathit K}^{+}}$
$40$ $\pm19$ $\pm5$ 20
 2006
BELL ${{\mathit B}^{+}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\overline{\mathit \Lambda}}}{{\mathit K}^{+}}$
$24.8$ $\pm3.4$ $\pm3.5$ 592
 2004
CLEO ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ $\rightarrow$ ${{\mathit K}_S^0}$ ${{\mathit K}^{\pm}}{{\mathit \pi}^{\mp}}$
$20.4$ ${}^{+7.7}_{-6.7}$ $\pm2.0$ 190
 2003
E835 ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \eta}_{{c}}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$
$23.9$ ${}^{+12.6}_{-7.1}$
 1995 F
E760 ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$
• • We do not use the following data for averages, fits, limits, etc. • •
$32.1$ $\pm1.1$ $\pm1.3$ 12k 9
 2011 M
BABR ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit K}_S^0}$ ${{\mathit K}^{\pm}}{{\mathit \pi}^{\mp}}$
$34.3$ $\pm2.3$ $\pm0.9$ 2.5k 10
 2004 D
BABR ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit \eta}_{{c}}{(1S)}}$ $\rightarrow$ ${{\mathit K}}{{\overline{\mathit K}}}{{\mathit \pi}}$
$17.0$ $\pm3.7$ $\pm7.4$ 11
 2003
BES ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}_{{c}}}$
$29$ $\pm8$ $\pm6$ 180 12
 2003
BELL ${{\mathit B}}$ $\rightarrow$ ${{\mathit \eta}_{{c}}}{{\mathit K}}$
$11.0$ $\pm8.1$ $\pm4.1$ 13
 2000 F
BES ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}_{{c}}}$ and ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}_{{c}}}$
$27.0$ $\pm5.8$ $\pm1.4$ 14
 2000 B
CLE2 ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit \eta}_{{c}}}$ $\rightarrow$ ${{\mathit K}^{\pm}}{{\mathit K}_S^0}$ ${{\mathit \pi}^{\mp}}$
$7.0$ ${}^{+7.5}_{-7.0}$ 12
 1987 B
SPEC ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$
$10.1$ ${}^{+33.0}_{-8.2}$ 23 15
 1986
MRK3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit p}}{{\overline{\mathit p}}}$
$11.5$ $\pm4.5$
 1986
CBAL ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}$ X, ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}$ X
$< 40 90\% CL$ 18
 1980 B
MRK2 ${{\mathit e}^{+}}{{\mathit e}^{-}}$
$< 20 90\% CL$
 1980 B
CBAL ${{\mathit e}^{+}}{{\mathit e}^{-}}$
 1 From a fit of the ${{\mathit \phi}}{{\mathit \phi}}$ invariant mass with the mass and width of ${{\mathit \eta}_{{c}}{(1S)}}$ as free parameters.
 2 Taking into account an asymmetric photon lineshape.
 3 With floating mass.
 4 Ignoring possible interference with the non-resonant 0${}^{-}$ amplitude.
 5 Using both, ${{\mathit \eta}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$ and ${{\mathit \eta}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ decays.
 6 From a simultaneous fit to six decay modes of the ${{\mathit \eta}_{{c}}}$.
 7 Accounts for interference with non-resonant continuum.
 8 Taking into account interference with the non-resonant $\mathit J{}^{P} = 0-$ amplitude.
 9 Not independent from the measurements reported by LEES 2010 .
 10 Superseded by LEES 2010 .
 11 From a simultaneous fit of five decay modes of the ${{\mathit \eta}_{{c}}}$.
 12 Superseded by VINOKUROVA 2011 .
 13 From a fit to the 4-prong invariant mass in ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}_{{c}}}$ and ${{\mathit J / \psi}{(1S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}_{{c}}}$ decays.
 14 Superseded by ASNER 2004 .
 15 Positive and negative errors correspond to 90$\%$ confidence level.
References:
 ABLIKIM 2019AV
PR D100 052012 Observation of $\eta_c\to\omega\omega$ in $J/\psi\to\gamma\omega\omega$
 XU 2018
PR D98 072001 Measurement of eta_c(1S), eta_c(2S) and non-resonant eta' pi+ pi- production via two-photon collisions
PL B769 305 Observation of ${{\mathit \eta}_{{c}}{(2S)}}$ $\rightarrow$ ${{\mathit p}}{{\overline{\mathit p}}}$ and Search for ${{\mathit X}{(3872)}}$ $\rightarrow$ ${{\mathit p}}{{\overline{\mathit p}}}$ Decays
 AAIJ 2017BB
EPJ C77 609 Study of Charmonium Production in hadron Decays and First Evidence for the Decay ${{\mathit B}_{{s}}^{0}}$ $\rightarrow$ ${{\mathit \phi}}{{\mathit \phi}}{{\mathit \phi}}$
 ANASHIN 2014
PL B738 391 Measurement of ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}_{{c}}}$ Decay Rate and ${{\mathit \eta}_{{c}}}$ Parameters at KEDR
 LEES 2014E
PR D89 112004 Dalitz Plot Analysis of ${{\mathit \eta}_{{c}}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit \eta}}$ and ${{\mathit \eta}_{{c}}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit \pi}^{0}}$ in Two-Photon Interactions
 ABLIKIM 2012N
PR D86 092009 Study of ${{\mathit \psi}{(3686)}}$ $\rightarrow$ ${{\mathit \pi}^{0}}{{\mathit h}_{{c}}}$ , ${{\mathit h}_{{c}}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}_{{c}}}$ via ${{\mathit \eta}_{{c}}}$ Exclusive Decays
 ABLIKIM 2012F
PRL 108 222002 Measurements of the Mass and Width of the ${{\mathit \eta}_{{c}}}$ Using the Decay ${{\mathit \psi}{(3686)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}_{{c}}}$
 ZHANG 2012A
PR D86 052002 First Study of ${{\mathit \eta}_{{c}}{(1S)}}$, ${{\mathit \eta}{(1760)}}$ and ${{\mathit X}{(1835)}}$ Production via ${{\mathit \eta}^{\,'}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ Final States in Two-Photon Collisions
 DEL-AMO-SANCHEZ 2011M
PR D84 012004 Observation of ${{\mathit \eta}_{{c}}{(1S)}}$ and ${{\mathit \eta}_{{c}}{(2S)}}$ decays to ${{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ in Two-Photon Interactions
 VINOKUROVA 2011
PL B706 139 Study of ${{\mathit B}^{\pm}}$ $\rightarrow$ ${{\mathit K}^{\pm}}$ ($\mathit KSK{{\mathit \pi}}$) Decay and Determination of ${{\mathit \eta}_{{c}}}$ and ${{\mathit \eta}_{{c}}{(2S)}}$ Parameters
 LEES 2010
PR D81 052010 Measurement of the ${{\mathit \gamma}}$ ${{\mathit \gamma}^{*}}$ $\rightarrow$ ${{\mathit \eta}_{{c}}}$ Transition Form Factor
 AUBERT 2008AB
PR D78 012006 Study of ${{\mathit B}}$-Meson Decays to ${{\mathit \eta}_{{c}}}{{\mathit K}^{(*)}}$ , ${{\mathit \eta}_{{c}}{(2S)}}{{\mathit K}^{(*)}}$ , and ${{\mathit \eta}_{{c}}}{{\mathit \gamma}}{{\mathit K}^{(*)}}$
 UEHARA 2008
EPJ C53 1 Study of Charmonia in Four-Meson Final States Produced in Two-Photon Collisions
 WU 2006
PRL 97 162003 Study of ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit p}}{{\overline{\mathit p}}}$ , ${{\mathit \Lambda}}{{\overline{\mathit \Lambda}}}$ and Observation of ${{\mathit \eta}_{{c}}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\overline{\mathit \Lambda}}}$ at Belle
 ASNER 2004
PRL 92 142001 Observation of ${{\mathit \eta}_{{c}}^{\,'}}$ Production in ${{\mathit \gamma}}{{\mathit \gamma}}$ Fusion at CLEO
 AUBERT 2004D
PRL 92 142002 Measurements of the Mass and Width of the ${{\mathit \eta}_{{c}}}$ Meson and of an ${{\mathit \eta}_{{c}}{(2S)}}$ Candidate
 AMBROGIANI 2003
PL B566 45 Measurement of the Resonance Parameters of the Charmonium Ground State, ${{\mathit \eta}_{{c}}}(1_{1}S_{0}$)
 BAI 2003
PL B555 174 Measurement of the Mass and Full Width of the ${{\mathit \eta}_{{c}}}$ Meson
 FANG 2003
PRL 90 071801 Measurement of Branching Fractions for ${{\mathit B}}$ $\rightarrow$ ${{\mathit \eta}_{{c}}}{{\mathit K}}{}^{(*)}$ Decays
 BAI 2000F
PR D62 072001 A Measurement of the Mass and Full Width of the ${{\mathit \eta}_{{c}}}$ Meson
 BRANDENBURG 2000B
PRL 85 3095 Measurements of the Mass, Total Width and Two Photon Partial Width of the ${{\mathit \eta}_{{c}}}$ Meson
 ARMSTRONG 1995F
PR D52 4839 Study of the ${{\mathit \eta}_{{c}}}(1{}^{1}{{\mathit S}_{{0}}}$) State of Charmonium Formed in ${{\overline{\mathit p}}}{{\mathit p}}$ Annihilations and a Search for the ${{\mathit \eta}_{{c}}}(2{}^{1}{{\mathit S}_{{0}}}$)
 BAGLIN 1987B
PL B187 191 Direct Observation and Partial Width Measurement of ${{\mathit \gamma}}{{\mathit \gamma}}$ Decay of Charmonium States
 BALTRUSAITIS 1986
PR D33 629 Hadronic Decay of the ${{\mathit \eta}_{{c}}{(2980)}}$
 GAISER 1986
PR D34 711 Charmonium Spectroscopy from Inclusive ${{\mathit \psi}^{\,'}}$ and ${{\mathit J / \psi}}$ Radiative Decays
 HIMEL 1980B
PRL 45 1146 Observation of the ${{\mathit \eta}_{{c}}{(2980)}}$ Produced in the Radiative Decay of the ${{\mathit \psi}^{\,'}{(3684)}}$
 PARTRIDGE 1980B
PRL 45 1150 Observation of an ${{\mathit \eta}_{{c}}}$ Candidate State with Mass $2978$ $\pm9$ MeV
see fit info