${{\mathit \eta}_{{c}}{(2S)}}$ MASS

INSPIRE   PDGID:
M059M
VALUE (MeV) EVTS DOCUMENT ID TECN  COMMENT
$\bf{ 3637.7 \pm1.1}$ OUR AVERAGE  Error includes scale factor of 1.2.
$3643.4$ $\pm2.3$ $\pm4.4$ 569
ABLIKIM
2022Q
 BES3 ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}$3( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$)
$3635.1$ $\pm3.7$ $\pm2.9$ 106
XU
2018
BELL ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit \eta}^{\,'}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
$3633.6$ $\pm1.7$ $\pm0.6$ 106 1
AAIJ
2017AD
 LHCB ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit B}^{+}}{{\mathit X}}$ $\rightarrow$ ${{\mathit p}}{{\overline{\mathit p}}}{{\mathit K}^{+}}{{\mathit X}}$
$3636.4$ $\pm4.1$ $\pm0.7$ 365 2
AAIJ
2017BB
 LHCB ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}{{\mathit X}}$ $\rightarrow$ 2( ${{\mathit K}^{+}}{{\mathit K}^{-}}$) ${{\mathit X}}$
$3637.0$ $\pm5.7$ $\pm3.4$ 178 3, 4
LEES
2014E
 BABR ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit \pi}^{0}}$
$3635.1$ $\pm5.8$ $\pm2.1$ 47 3, 5
LEES
2014E
 BABR ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit \eta}}$
$3646.9$ $\pm1.6$ $\pm3.6$ $57$ $\pm17$
ABLIKIM
2013K
 BES3 ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit K}_S^0}$ ${{\mathit K}^{\pm}}{{\mathit \pi}^{\mp}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
$3637.6$ $\pm2.9$ $\pm1.6$ $127$ $\pm18$ 6
ABLIKIM
2012G
 BES3 ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit K}^{0}}{{\mathit K}}{{\mathit \pi}}$ , ${{\mathit K}}{{\mathit K}}{{\mathit \pi}^{0}}$
$3638.5$ $\pm1.5$ $\pm0.8$ 624 3
DEL-AMO-SANCH..
2011M
 BABR ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit K}_S^0}$ ${{\mathit K}^{\pm}}{{\mathit \pi}^{\mp}}$
$3640.5$ $\pm3.2$ $\pm2.5$ 1201 3
DEL-AMO-SANCH..
2011M
 BABR ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$
$3636.1$ ${}^{+3.9}_{-4.2}$ ${}^{+0.7}_{-2.0}$ 128 7
VINOKUROVA
2011
BELL ${{\mathit B}^{\pm}}$ $\rightarrow$ ${{\mathit K}^{\pm}}$ ( ${{\mathit K}_S^0}$ ${{\mathit K}^{\pm}}{{\mathit \pi}^{\mp}}$ )
$3626$ $\pm5$ $\pm6$ 311 8
ABE
2007
BELL ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit J / \psi}}$( ${{\mathit c}}{{\overline{\mathit c}}}$)
$3645.0$ $\pm5.5$ ${}^{+4.9}_{-7.8}$ $121$ $\pm27$
AUBERT
2005C
 BABR ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit c}}{{\overline{\mathit c}}}$
$3642.9$ $\pm3.1$ $\pm1.5$ 61
ASNER
2004
CLEO ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit \eta}_{{c}}^{\,'}}$ $\rightarrow$ ${{\mathit K}_S^0}$ ${{\mathit K}^{\pm}}{{\mathit \pi}^{\mp}}$
• • We do not use the following data for averages, fits, limits, etc. • •
$3639$ $\pm7$ $98$ $\pm52$ 9
AUBERT
2006E
 BABR ${{\mathit B}^{\pm}}$ $\rightarrow$ ${{\mathit K}^{\pm}}{{\mathit X}}$ $_{ {{\mathit c}} {{\overline{\mathit c}}} }$
$3630.8$ $\pm3.4$ $\pm1.0$ $112$ $\pm24$ 10
AUBERT
2004D
 BABR ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit \eta}_{{c}}{(2S)}}$ $\rightarrow$ ${{\mathit K}}{{\overline{\mathit K}}}{{\mathit \pi}}$
$3654$ $\pm6$ $\pm8$ $39$ $\pm11$ 11
CHOI
2002
BELL ${{\mathit B}}$ $\rightarrow$ ${{\mathit K}}{{\mathit K}_{{S}}}{{\mathit K}^{-}}{{\mathit \pi}^{+}}$
$3594$ $\pm5$ 12
EDWARDS
1982C
 CBAL ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \gamma}}$ X
1  AAIJ 2017AD report ${\mathit m}_{{{\mathit \psi}{(2S)}}}–{\mathit m}_{{{\mathit \eta}_{{c}}{(2S)}}}$ = $52.5$ $\pm1.7$ $\pm0.6$ MeV. We use the current value ${\mathit m}_{{{\mathit \psi}{(2S)}}}$ = $3686.097$ $\pm0.025$ MeV to obtain the quoted mass.
2  From a fit of the ${{\mathit \phi}}{{\mathit \phi}}$ invariant mass with the width of ${{\mathit \eta}_{{c}}{(2S)}}$ fixed to the PDG 2016 value.
3  Ignoring possible interference with continuum.
4  With a width fixed to 11.3 MeV.
5  With a width fixed to 11.3 MeV. 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 ${{\mathit K}_S^0}$ ${{\mathit K}^{\pm}}{{\mathit \pi}^{\mp}}$ and ${{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit \pi}^{0}}$ decay modes.
7  Accounts for interference with non-resonant continuum.
8  From a fit of the ${{\mathit J / \psi}}$ recoil mass spectrum. Supersedes ABE,K 2002 and ABE 2004G.
9  From the fit of the kaon momentum spectrum. Systematic errors not evaluated.
10  Superseded by DEL-AMO-SANCHEZ 2011M.
11  Superseded by VINOKUROVA 2011 .
12  Assuming mass of ${{\mathit \psi}{(2S)}}$ = 3686 MeV.
References:
ABLIKIM 2022Q
PR D106 032014 Observation of $\eta_c(2S) \to 3(\pi^+\pi^-)$ and measurements of $\chi_{cJ} \to 3(\pi^+\pi^-)$ in $\psi(3686)$ radiative transitions
XU 2018
PR D98 072001 Measurement of eta_c(1S), eta_c(2S) and non-resonant eta' pi+ pi- production via two-photon collisions
AAIJ 2017BB
EPJ C77 609 Study of Charmonium Production in hadron Decays and First Evidence for the Decay ${{\mathit B}_{{s}}^{0}}$ $\rightarrow$ ${{\mathit \phi}}{{\mathit \phi}}{{\mathit \phi}}$
AAIJ 2017AD
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
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 2013K
PR D87 052005 Evidence for ${{\mathit \eta}_{{c}}{(2S)}}$ in ${{\mathit \psi}{(3686)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit K}_S^0}$ ${{\mathit K}^{\pm}}{{\mathit \pi}^{\mp}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
ABLIKIM 2012G
PRL 109 042003 First Observation of the $\mathit M$1 Transition ${{\mathit \psi}{(3686)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}_{{c}}{(2S)}}$
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
ABE 2007
PRL 98 082001 Observation of a Charmoniumlike State Produced in Association with ${{\mathit J / \psi}}$ in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Annihilation at $\sqrt {s }$ $\sim{}$ 10.6 GeV
AUBERT 2006E
PRL 96 052002 Measurements of the Absolute Branching Fractions of ${{\mathit B}^{\pm}}$ $\rightarrow$ ${{\mathit K}^{\pm}}{{\mathit X}}$ $_{ {{\mathit c}} {{\overline{\mathit c}}} }$
AUBERT 2005C
PR D72 031101 Measurement of Double Charmonium Production in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Annihilations at $\sqrt {s }$ = 10.6 GeV
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
CHOI 2002
PRL 89 102001 Observation of the ${{\mathit \eta}_{{c}}{(2S)}}$ in Exclusive ${{\mathit B}}$ $\rightarrow$ ${{\mathit K}}{{\mathit K}_S^0}$ ${{\mathit K}^{-}}{{\mathit \pi}^{+}}$ Decays
EDWARDS 1982C
PRL 48 70 Observation an ${{\mathit \eta}_{{c}}^{\,'}}$ Candidate State with Mass $3592$ $\pm5$ MeV