${{\mathit \eta}{(1405)}}$ MASS

${{\mathit \eta}}{{\mathit \pi}}{{\mathit \pi}}$ MODE

INSPIRE   JSON  (beta) PDGID:
M027M1
M027M1
VALUE (MeV) EVTS DOCUMENT ID TECN  COMMENT
$\bf{ 1405.5 \pm2.3}$ OUR AVERAGE  Error includes scale factor of 2.2.  See the ideogram below.
$1404$ ${}^{+0.8}_{-1.5}$ ${}^{+2.0}_{-8.1}$ 1
ABLIKIM
2025AB
 
BES3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \pi}^{0}}{{\mathit f}_{{{0}}}{(980)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$
$1409.0$ $\pm1.7$ 743
ABLIKIM
2012E
 
BES3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}$( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$)
$1407.0$ $\pm3.5$ 198
ABLIKIM
2012E
 
BES3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}$( ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$)
$1399.8$ $\pm2.2$ ${}^{+2.8}_{-0.1}$ 2
ABLIKIM
2011J
 
BES3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \omega}}({{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$)
$1392$ $\pm14$ $900$ $\pm375$
AMSLER
2004B
 
CBAR 0 ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \eta}}$
$1394$ $\pm8$ $6.6$ $\pm2.0$k
AMSLER
2004B
 
CBAR 0 ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit \eta}}$
$1404$ $\pm6$ 9082
MANAK
2000A
 
MPS 18 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit n}}$
$1424$ $\pm6$ 2200
ALDE
1997B
 
GAM4 100 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit n}}$
$1400$ $\pm6$ 3
BOLTON
1992B
 
MRK3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
$1388$ $\pm4$
FUKUI
1991C
 
SPEC 8.95 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit n}}$
$1398$ $\pm6$ 261 4
AUGUSTIN
1990
 
DM2 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
$1420$ $\pm5$
ANDO
1986
 
SPEC 8 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit n}}$
• • We do not use the following data for averages, fits, limits, etc. • •
$1404.0$ $\pm11.0$ 195
ABLIKIM
2019BA
 
BES3 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \psi}{(2S)}}$
$1385$ $\pm7$
BAI
1999
 
BES ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
$1409$ $\pm3$ 5
AMSLER
1995F
 
CBAR 0 ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit \eta}}$
1  ABLIKIM 2025AB measured ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}{(1405)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \pi}^{0}}{{\mathit f}_{{{0}}}{(980)}}$ $/$ ${}^{}0{}^{++}$ $\mathit PHSP$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$. Here ${{\mathit \gamma}}{{\mathit \pi}^{0}}{{\mathit f}_{{{0}}}{(980)}}$ $/$ ${}^{}0{}^{++}$ $\mathit PHSP$ indicates an intermediate state which could be either ${{\mathit \gamma}}{{\mathit \pi}^{0}}{{\mathit f}_{{{0}}}{(980)}}$ or ${{\mathit \gamma}}{{\mathit \pi}^{0}}{}^{}0{}^{++}$ phase space.
2  The selected process is ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \omega}}{{\mathit a}_{{{0}}}{(980)}}{{\mathit \pi}}$.
3  From fit to the ${{\mathit a}_{{{0}}}{(980)}}{{\mathit \pi}}{}^{}0{}^{-+}$ partial wave.
4  Best fit with a single Breit Wigner.
5  Superseded by AMSLER 04B.

           ${{\mathit \eta}{(1405)}}$ mass, ${{\mathit \eta}}{{\mathit \pi}}{{\mathit \pi}}$ mode (MeV)
References