# ${{\boldsymbol \eta}}{{\boldsymbol \pi}}$ FINAL STATE ONLY INSPIRE search

VALUE (MeV) EVTS DOCUMENT ID TECN CHG  COMMENT
• • • We do not use the following data for averages, fits, limits, etc. • • •
$982.5$ $\pm1.6$ $\pm1.1$ 16.9k 1
 2009 F
KLOE 1.02 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{0}}{{\mathit \gamma}}$
$986$ $\pm4$
 2009
RVUE 0.0 ${{\overline{\mathit p}}}{{\mathit p}}$ , ${{\mathit \pi}}{{\mathit N}}$
$982.3$ ${}^{+0.6}_{-0.7}$ ${}^{+3.1}_{-4.7}$ 2
 2009 A
BELL ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit \pi}^{0}}{{\mathit \eta}}$
$987.4$ $\pm1.0$ $\pm3.0$ 3, 4
 2008 A
RVUE 0 ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit \eta}}$
$989.1$ $\pm1.0$ $\pm3.0$ 5, 4
 2008 A
RVUE 0 ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit \eta}}$
$985$ $\pm4$ $\pm6$ 318
 2002 B
L3 $183 - 209$ ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ ${{\mathit e}^{-}}$ ${{\mathit \eta}}$ ${{\mathit \pi}^{+}}$ ${{\mathit \pi}^{-}}$
$995$ ${}^{+52}_{-10}$ 36 6
 2000 F
SND ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{0}}{{\mathit \gamma}}$
$994$ ${}^{+33}_{-8}$ 36 7
 2000 F
SND ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{0}}{{\mathit \gamma}}$
$975$ $\pm7$
 2000 H
450 ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit p}_{{f}}}{{\mathit \eta}}{{\mathit \pi}^{0}}{{\mathit p}_{{s}}}$
$988$ $\pm8$
 2000 H
450 ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Delta}_{{f}}^{++}}{{\mathit \eta}}{{\mathit \pi}^{-}}{{\mathit p}_{{s}}}$
$\sim{}\text{ 1055}$ 8
 1999
RVUE ${{\mathit \eta}}{{\mathit \pi}}$ , ${{\mathit K}}{{\overline{\mathit K}}}$
$\sim{}\text{ 1009.2}$ 8
 1999 B
RVUE ${{\mathit \pi}}$ ${{\mathit \pi}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit \pi}}$ , ${{\mathit K}}{{\overline{\mathit K}}}$
$993.1$ $\pm2.1$ 9
 1999
B852 $18.3$ ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit n}}$
$988$ $\pm6$ 8
 1998 B
RVUE Compilation
$987$
 1996
RVUE ${{\mathit \pi}}$ ${{\mathit \pi}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit \pi}}$ , ${{\mathit K}}{{\overline{\mathit K}}}$ , ${{\mathit K}}{{\mathit \pi}}$ , ${{\mathit \eta}}{{\mathit \pi}}$
$991$
 1995
RVUE ${{\mathit \eta}}$ ${{\mathit \pi}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}}$ , ${{\mathit K}}{{\overline{\mathit K}}}$ , ${{\mathit K}}{{\mathit \pi}}$ , ${{\mathit \eta}}{{\mathit \pi}}$
$984.45$ $\pm1.23$ $\pm0.34$
 1994 C
CBAR $0.0$ ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \omega}}{{\mathit \eta}}{{\mathit \pi}^{0}}$
$982$ $\pm2$ 10
 1992
CBAR 0.0 ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \eta}}{{\mathit \pi}^{0}}$
$984$ $\pm4$ 1040 10
 1991 B
OMEG $\pm{}$ 300 ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit p}}{{\mathit p}}{{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
$976$ $\pm6$
 1984 E
OMEG $\pm{}$ 25$-$55 ${{\mathit \gamma}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}}{{\mathit n}}$
$986$ $\pm3$ 500 11
 1981
OMEG $\pm{}$ 12 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{-}}{{\mathit p}}$
$990$ $\pm7$ 145 11
 1979
HBC $\pm{}$ 4.2 ${{\mathit K}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \eta}}$2 ${{\mathit \pi}}$
$980$ $\pm11$ 47
 1978
OSPK - 4.5 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit p}}{{\mathit X}^{-}}$
$978$ $\pm16$ 50
 1978
OMEG $\pm{}$ 12$-$15 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit n}}{{\mathit \eta}}$2 ${{\mathit \pi}}$
$977$ $\pm7$
 1977
HBC - 16 ${{\mathit \pi}^{\mp}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \eta}}$3 ${{\mathit \pi}}$
$989$ $\pm4$ 70
 1975
HBC - 3.1$-$6 ${{\mathit K}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \eta}}$2 ${{\mathit \pi}}$
$972$ $\pm10$ 150
 1972
HBC $\pm{}$ 0.7 ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ 7 ${{\mathit \pi}}$
$970$ $\pm15$ 20
 1969 C
HBC - 4$-$5 ${{\mathit K}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \eta}}$2 ${{\mathit \pi}}$
$980$ $\pm10$
 1969
DBC $\pm{}$ 2.7 ${{\mathit \pi}^{+}}{{\mathit d}}$
$980$ $\pm10$ 15
 1969 B
HBC - 4.5 ${{\mathit K}^{-}}$ ${{\mathit N}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}}{{\mathit \Lambda}}$
$980$ $\pm10$ 30
 1968
HBC $\pm{}$ 5.5 ${{\mathit K}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \eta}}$2 ${{\mathit \pi}}$
1  Using the model of ACHASOV 1989 and ACHASOV 2003B.
2  From a fit with the S-wave amplitude including two interfering Breit-Wigners plus a background term.
3  Parameterizes couplings to ${{\overline{\mathit K}}}{{\mathit K}}$ , ${{\mathit \pi}}{{\mathit \eta}}$ , and ${{\mathit \pi}}{{\mathit \eta}^{\,'}}$ .
4  Using AMSLER 1994D and ABELE 1998 .
5  From the T-matrix pole on sheet II.
6  Using the model of ACHASOV 1989 . Supersedes ACHASOV 1998B.
7  Using the model of JAFFE 1977 . Supersedes ACHASOV 1998B.
8  T-matrix pole.
9  Breit-Wigner fit, average between ${{\mathit a}_{{0}}^{\pm}}$ and ${{\mathit a}_{{0}}^{0}}$. The fit favors a slightly heavier ${{\mathit a}_{{0}}^{\pm}}$.
10  From a single Breit-Wigner fit.
11  From ${{\mathit f}_{{1}}{(1285)}}$ decay.
References:
 AMBROSINO 2009F
PL B681 5 Study of the ${{\mathit a}_{{0}}{(980)}}$ Meson via the Radiative Decay ${{\mathit \phi}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{0}}{{\mathit \gamma}}$ with the KLOE Detector
 ANISOVICH 2009
IJMP A24 2481 The Combined Analysis of ${{\mathit \pi}}$ ${{\mathit N}}$ $\rightarrow$ two mesons ${+}$ ${{\mathit N}}$ Reactions within Reggeon Exchanges and Data for ${{\mathit p}}$ ${{\overline{\mathit p}}}$ (at rest) $\rightarrow$ three mesons
 UEHARA 2009A
PR D80 032001 High-Statistics Study of ${{\mathit \eta}}{{\mathit \pi}^{0}}$ Production in Two-Photon Collisions
 BUGG 2008A
PR D78 074023 Reanalysis of Data on ${{\mathit a}_{{0}}{(1450)}}$ and ${{\mathit a}_{{0}}{(980)}}$
 ACHARD 2002B
PL B526 269 ${{\mathit f}_{{1}}{(1285)}}$ Formation in Two Photon Collisions at LEP
 ACHASOV 2000F
PL B479 53 The ${{\mathit \phi}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{0}}{{\mathit \gamma}}$ Decay
 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 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
 OLLER 1999
PR D60 099906 (erratum) Meson-Meson Interaction in a Nonperturbative Chiral Approach
 TEIGE 1999
PR D59 012001 Properties of the ${{\mathit a}_{{0}}{(980)}}$ Meson
 ANISOVICH 1998B
SPU 41 419 The Lightest Scalar Glueball
 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 ${\mathrm {GeV/}}\mathit c$
 ATKINSON 1984E
PL 138B 459 Inclusive Photoproduction of ${{\mathit \delta}{(980)}}$ and ${{\mathit B}{(1235)}}$ at High x$_{F}$
 EVANGELISTA 1981
NP B178 197 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 ${\mathrm {GeV/}}\mathit c$
 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 ${\mathrm {MeV}}/\mathit c$
 BARNES 1969C
PRL 23 610 Evidence for a ${{\mathit \pi}}{{\mathit \eta}}$ Resonance at 970 MeV Produced in ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ Missing Mass at 3.9, 4.6, and 5.0 ${\mathrm {GeV/}}\mathit c$
 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 ${\mathrm {GeV/}}\mathit c$
 AMMAR 1968
PRL 21 1832 Boson Resonance of Mass 980 MeV Decaying into ${{\mathit \pi}}{{\mathit \eta}}$