${{\mathit a}_{{0}}{(980)}}$ WIDTH

INSPIRE   PDGID:
M036W1
VALUE (MeV) EVTS DOCUMENT ID TECN CHG  COMMENT
$\bf{ 50\text{ to }100 }$ OUR ESTIMATE  Width determination very model dependent. Peak width in ${{\mathit \eta}}{{\mathit \pi}}$ is about 60 MeV, but decay width can be much larger.
• • We do not use the following data for averages, fits, limits, etc. • •
$97.2$ $\pm1.9$ $\pm5.7$ 1
ALBRECHT
2020
CBAR 0.9 ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit \eta}}$ , ${{\mathit \pi}^{0}}{{\mathit \eta}}{{\mathit \eta}}$ , ${{\mathit \pi}^{0}}{{\mathit K}^{+}}{{\mathit K}^{-}}$
$73.2$ ${}^{+25.4}_{-5.2}$ 2
LU
2020
RVUE ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit \pi}^{0}}{{\mathit \eta}}$ , ${{\mathit K}_S^0}$ ${{\mathit K}_S^0}$
$75.6$ $\pm1.6$ ${}^{+17.4}_{-10.0}$ 3
UEHARA
2009A
 BELL ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit \pi}^{0}}{{\mathit \eta}}$
$50$ $\pm13$ $\pm4$ 318
ACHARD
2002B
 L3 $183 - 209$ ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ ${{\mathit e}^{-}}$ ${{\mathit \eta}}$ ${{\mathit \pi}^{+}}$ ${{\mathit \pi}^{-}}$
$72$ $\pm16$
BARBERIS
2000H
 450 ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit p}_{{f}}}{{\mathit \eta}}{{\mathit \pi}^{0}}{{\mathit p}_{{s}}}$
$61$ $\pm19$
BARBERIS
2000H
 450 ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Delta}_{{f}}^{++}}{{\mathit \eta}}{{\mathit \pi}^{-}}{{\mathit p}_{{s}}}$
$\sim{}\text{ 42}$ 4
OLLER
1999
RVUE ${{\mathit \eta}}{{\mathit \pi}}$ , ${{\mathit K}}{{\overline{\mathit K}}}$
$\sim{}\text{ 112}$ 4
OLLER
1999B
 RVUE ${{\mathit \pi}}$ ${{\mathit \pi}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}}$ , ${{\mathit K}}{{\overline{\mathit K}}}$
$71$ $\pm7$
TEIGE
1999
B852 $18.3$ ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit n}}$
$92$ $\pm20$ 4
ANISOVICH
1998B
 RVUE Compilation
$65$ $\pm10$ 5
BERTIN
1998B
 OBLX $\pm{}$ 0.0 ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit K}^{\pm}}{{\mathit K}_{{s}}}{{\mathit \pi}^{\mp}}$
$\sim{}\text{ 100}$
TORNQVIST
1996
RVUE ${{\mathit \pi}}$ ${{\mathit \pi}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit \pi}}$ , ${{\mathit K}}{{\overline{\mathit K}}}$ , ${{\mathit K}}{{\mathit \pi}}$ , ${{\mathit \eta}}{{\mathit \pi}}$
$202$
JANSSEN
1995
RVUE ${{\mathit \eta}}$ ${{\mathit \pi}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}}$ , ${{\mathit K}}{{\overline{\mathit K}}}$ , ${{\mathit K}}{{\mathit \pi}}$ , ${{\mathit \eta}}{{\mathit \pi}}$
$54.12$ $\pm0.34$ $\pm0.12$
AMSLER
1994C
 CBAR $0.0$ ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \omega}}{{\mathit \eta}}{{\mathit \pi}^{0}}$
$54$ $\pm10$ 6
AMSLER
1992
CBAR 0.0 ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \eta}}{{\mathit \pi}^{0}}$
$95$ $\pm14$ 1040 6
ARMSTRONG
1991B
 OMEG $\pm{}$ 300 ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit p}}{{\mathit p}}{{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
$62$ $\pm15$ 500 7
EVANGELISTA
1981
OMEG $\pm{}$ 12 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{-}}{{\mathit p}}$
$60$ $\pm20$ 145 7
GURTU
1979
HBC $\pm{}$ 4.2 ${{\mathit K}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \eta}}$2 ${{\mathit \pi}}$
$60$ ${}^{+50}_{-30}$ 47
CONFORTO
1978
OSPK - 4.5 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit p}}{{\mathit X}^{-}}$
$86.0$ ${}^{+60.0}_{-50.0}$ 50
CORDEN
1978
OMEG $\pm{}$ 12$-$15 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit n}}{{\mathit \eta}}$2 ${{\mathit \pi}}$
$44$ $\pm22$
GRASSLER
1977
HBC - 16 ${{\mathit \pi}^{\mp}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \eta}}$3 ${{\mathit \pi}}$
$80\text{ to }300 $ 8
FLATTE
1976
RVUE - 4.2 ${{\mathit K}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \eta}}$2 ${{\mathit \pi}}$
$16.0$ ${}^{+25.0}_{-16.0}$ 70 9
WELLS
1975
HBC - 3.1$-$6 ${{\mathit K}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \eta}}$2 ${{\mathit \pi}}$
$30$ $\pm5$ 150 10
DEFOIX
1972
HBC $\pm{}$ 0.7 ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ 7 ${{\mathit \pi}}$
$40$ $\pm15$
CAMPBELL
1969
DBC $\pm{}$ 2.7 ${{\mathit \pi}^{+}}{{\mathit d}}$
$60$ $\pm30$ 15
MILLER
1969B
 HBC - 4.5 ${{\mathit K}^{-}}$ ${{\mathit N}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}}{{\mathit \Lambda}}$
$80$ $\pm30$ 30
AMMAR
1968
HBC $\pm{}$ 5.5 ${{\mathit K}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \eta}}$2 ${{\mathit \pi}}$
1  T-matrix pole with 2 poles, 2 channels, pole width on adjacent sheet $127.0$ $\pm2.3$ $\pm6.7$ MeV.
2  T-matrix pole on sheet II.
3  From a fit with the S-wave amplitude including two interfering Breit-Wigners plus a background term.
4  T-matrix pole.
5  The ${{\mathit \eta}}{{\mathit \pi}}$ width.
6  From a single Breit-Wigner fit.
7  From ${{\mathit f}_{{1}}{(1285)}}$ decay.
8  Using a two-channel resonance parametrization of GAY 1976B data.
9  Weak evidence only for ${{\mathit a}_{{0}}{(980)}^{+}}$ production.
10  This number has very little meaning. Error is much too small. Vlada
References:
ALBRECHT 2020
EPJ C80 453 Coupled channel analysis of ${\bar{p}p}\,\rightarrow \,\pi ^0\pi ^0\eta $, ${\pi ^0\eta \eta }$ and ${K^+K^-\pi ^0}$ at 900 MeV/c and of ${\pi \pi }$-scattering data
LU 2020
EPJ C80 436 The $\pi \eta $ interaction and $a_0$ resonances in photon?photon scattering
UEHARA 2009A
PR D80 032001 High-Statistics Study of ${{\mathit \eta}}{{\mathit \pi}^{0}}$ Production in Two-Photon Collisions
ACHARD 2002B
PL B526 269 ${{\mathit f}_{{1}}{(1285)}}$ Formation in Two Photon Collisions at LEP
BARBERIS 2000H
PL B488 225 A Study of the Centrally Produced ${{\mathit \eta}}{{\mathit \pi}^{0}}$ and ${{\mathit \eta}}{{\mathit \pi}^{-}}$ Systems in ${{\mathit p}}{{\mathit p}}$ Interactions at 450 ${\mathrm {GeV/}}\mathit c$
OLLER 1999
PR D60 099906 (erratum) Meson-Meson Interaction in a Nonperturbative Chiral Approach
OLLER 1999B
NP A652 407 (erratum) Chiral Symmetry Amplitudes in the S-wave Isoscalar and Isovector Channels and the ${{\mathit \sigma}}$, ${{\mathit f}_{{0}}{(980)}}$, ${{\mathit a}_{{0}}{(980)}}$ Scalar Mesons
TEIGE 1999
PR D59 012001 Properties of the ${{\mathit a}_{{0}}{(980)}}$ Meson
ANISOVICH 1998B
SPU 41 419 The Lightest Scalar Glueball
BERTIN 1998B
PL B434 180 Study of the Isovector Scalar Mesons in the Channel ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit K}^{\pm}}{{\mathit K}_S^0}$ ${{\mathit \pi}^{\mp}}$ at Rest with Initial Angular Momentum State
TORNQVIST 1996
PRL 76 1575 Resurrection of the ${{\mathit \sigma}}$ Meson
JANSSEN 1995
PR D52 2690 On the Structure of the Scalar Mesons ${{\mathit f}_{{0}}{(975)}}$ and ${{\mathit a}_{{0}}{(980)}}$
AMSLER 1994C
PL B327 425 Study of ${{\overline{\mathit p}}}{{\mathit p}}$ Annihilation at Rest into ${{\mathit \omega}}{{\mathit \eta}}{{\mathit \pi}^{0}}$
AMSLER 1992
PL B291 347 Proton Antiproton Annihilation into ${{\mathit \eta}}{{\mathit \eta}}{{\mathit \pi}}$: Observation of a Scalar Resonance Decaying into ${{\mathit \eta}}{{\mathit \eta}}$
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 ${\mathrm {GeV/}}\mathit c$
EVANGELISTA 1981
NP B178 197 Results from a ${{\mathit \pi}^{-}}{{\mathit p}}$ Slow Proton Trigger Experiment at 12 ${\mathrm {GeV/}}\mathit c$
Also
NP B186 594 Results from a ${{\mathit \pi}^{-}}{{\mathit p}}$ Slow Proton Trigger Experiment at 12 ${\mathrm {GeV/}}\mathit c$
GURTU 1979
NP B151 181 Production and Decay Properties of the ${{\mathit D}{(1285)}}$ Meson in ${{\mathit K}^{-}}{{\mathit p}}$ Interactions at 4.2 ${\mathrm {GeV/}}\mathit c$
CONFORTO 1978
LNC 23 419 Study of the ${{\mathit \delta}{(970)}}$ Meson
CORDEN 1978
NP B144 253 Observation of the ${{\mathit D}}$, ${{\mathit E}}$ and ${{\mathit \delta}}$ Mesons in ${{\mathit \pi}^{-}}{{\mathit p}}$ Interactions at 12 and 15 ${\mathrm {GeV/}}\mathit c$
GRASSLER 1977
NP B121 189 Production and Decay of the ${{\mathit \delta}{(970)}}$ and ${{\mathit D}{(1285)}}$ Mesons in ${{\mathit \pi}^{\pm}}{{\mathit p}}$ Interactions at 16 ${\mathrm {GeV/}}\mathit c$
FLATTE 1976
PL 63B 224 Coupled-Channel Analysis of the ${{\mathit \pi}}{{\mathit \eta}}$ and ${{\mathit K}}{{\overline{\mathit K}}}$ Systems near ${{\mathit K}}{{\overline{\mathit K}}}$ Threshold
WELLS 1975
NP B101 333 $\delta $ Production in $3.1 - 3.6$ ${\mathrm {GeV/}}\mathit c$ ${{\mathit K}^{-}}{{\mathit p}}$ Interactions
DEFOIX 1972
NP B44 125 Evidence for Decays of the ${{\mathit D}}$- and ${{\mathit E}}$-Mesons into ${{\mathit \sigma}}{{\mathit \pi}}$ in ${{\overline{\mathit p}}}{{\mathit p}}$ Annihilation at 700 ${\mathrm {MeV}}/\mathit c$
CAMPBELL 1969
PRL 22 1204 Study of ${{\mathit D}^{0}}$ $\rightarrow$ ${{\mathit \pi}^{\pm}}{{\mathit \delta}^{\mp}}$ and ${{\mathit \delta}^{\mp}}$ $\rightarrow$ ${{\mathit \pi}^{\mp}}{{\mathit \eta}}$ in the Reaction ${{\mathit \pi}^{+}}$ ${{\mathit d}}$ $\rightarrow$ ${{\mathit p}}$ $_{spect.}$ ${{\mathit p}}{{\mathit D}^{0}}$ at 2.7 ${\mathrm {GeV/}}\mathit c$
MILLER 1969B
PL 29B 255 Production of a ${{\mathit \pi}}-{{\mathit \eta}}$ Resonance at a Mass of 0.98 GeV in ${{\mathit K}^{-}}$ ${{\mathit n}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \pi}^{-}}{{\mathit \eta}}$ at 4.5 ${\mathrm {GeV/}}\mathit c$
Also
PR 188 2011 Final States with a Single Charged Particle and Visible ${{\mathit \Lambda}}$ from ${{\mathit K}}{{\mathit n}}$ Interactions at 4.5 ${\mathrm {GeV/}}\mathit c$
AMMAR 1968
PRL 21 1832 Boson Resonance of Mass 980 MeV Decaying into ${{\mathit \pi}}{{\mathit \eta}}$