# ${{\boldsymbol f}_{{4}}{(2050)}}$ MASS INSPIRE search

VALUE (MeV) EVTS DOCUMENT ID TECN  COMMENT
$\bf{ 2018 \pm11}$ OUR AVERAGE  Error includes scale factor of 2.1.
$1960$ $\pm15$
 2006
VES 36 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \omega}}{{\mathit \omega}}{{\mathit n}}$
$2005$ $\pm10$ 1
 2005
GAMS 33 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \eta}}{{\mathit n}}$
$1998$ $\pm15$
 1998
GAM4 100 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit n}}$
$2060$ $\pm20$
 1990
GAM2 38 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \omega}}{{\mathit \omega}}{{\mathit n}}$
$2038$ $\pm30$
 1987
DM2 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
$2086$ $\pm15$
 1987
MRK3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
$2000$ $\pm60$
 1986 D
GAM4 100 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit n}}$2 ${{\mathit \eta}}$
$2020$ $\pm20$ 40k 2
 1984 B
GAM2 38 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit n}}$2 ${{\mathit \pi}^{0}}$
$2015$ $\pm28$ 3
 1982
STRC 8 ${{\mathit \pi}^{+}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Delta}^{++}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$
$2031$ ${}^{+25}_{-36}$
 1982 B
MPS 23 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit n}}$2 ${{\mathit K}_S^0}$
$2020$ $\pm30$ 700
 1975
NICE 40 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit n}}$2 ${{\mathit \pi}^{0}}$
$2050$ $\pm25$
 1975
ASPK 18.4 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit n}}{{\mathit K}^{+}}{{\mathit K}^{-}}$
• • • We do not use the following data for averages, fits, limits, etc. • • •
$1966$ $\pm25$ 4
 2009
RVUE 0.0 ${{\overline{\mathit p}}}{{\mathit p}}$ , ${{\mathit \pi}}{{\mathit N}}$
$1885$ ${}^{+14}_{-13}$ ${}^{+218}_{-25}$ 5
 2009
BELL 10.6 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$
$2018$ $\pm6$
 2000 J
SPEC 2.0 ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$ , ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$ , ${{\mathit \eta}}{{\mathit \eta}}$ , ${{\mathit \eta}}{{\mathit \eta}^{\,'}}$ , ${{\mathit \pi}}{{\mathit \pi}}$
$\sim$$2000 6  1998 RVUE {{\mathit N}} {{\overline{\mathit N}}} \rightarrow {{\mathit \pi}}{{\mathit \pi}} \sim$$2010$ 7
 1997
RVUE ${{\overline{\mathit N}}}$ ${{\mathit N}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit \pi}}$
$\sim$$2040 8  1994 RVUE 0.36 - 1.55 {{\overline{\mathit p}}} {{\mathit p}} \rightarrow {{\mathit \pi}}{{\mathit \pi}} \sim$$1990$ 9
 1994
RVUE $0.36 - 1.55$ ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit \pi}}$
$1978$ $\pm5$ 10
 1980
CNTR 62 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit n}}$
$2040$ $\pm10$ 10
 1980
SPRK 18 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit p}}{{\overline{\mathit p}}}{{\mathit n}}$
$1935$ $\pm13$ 10
 1979
OMEG 12$-$15 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit n}}$2 ${{\mathit \pi}}$
$1988$ $\pm7$
 1979 B
OMEG 10 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit n}}$
$1922$ $\pm14$ 11
 1977
CIBS 25 ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit p}}$3 ${{\mathit \pi}}$
1  From the first PWA solution.
2  From a partial-wave analysis of the data.
3  From an amplitude analysis of the reaction ${{\mathit \pi}^{+}}$ ${{\mathit \pi}^{-}}$ $\rightarrow$ 2 ${{\mathit \pi}^{0}}$ .
4  K matrix pole.
5  Taking into account the ${{\mathit f}_{{2}}{(1950)}}$. Helicity-2 production favored.
6  Energy-dependent analysis.
7  Single energy analysis.
8  From solution A of amplitude analysis of data on ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit \pi}}$ . See however KLOET 1996 who fit ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ only and find waves only up to $\mathit J = 3$ to be important but not significantly resonant.
9  From solution B of amplitude analysis of data on ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit \pi}}$ . See however KLOET 1996 who fit ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ only and find waves only up to $\mathit J = 3$ to be important but not significantly resonant.
10  $\mathit I(\mathit J{}^{P}) = 0(4{}^{+})$ from amplitude analysis assuming one-pion exchange.
11  Width errors enlarged by us to 4${}\Gamma /\sqrt {\mathit N }$; see the note with the ${{\mathit K}^{*}{(892)}}$ mass.

${{\mathit f}_{{4}}{(2050)}}$ mass (MeV)
References:
 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 2009
PR D79 052009 High-Statistics Study of Neutral-Pion Pair Production in Two-Photon Collisions
 AMELIN 2006
PAN 69 690 Resonances in the ${{\mathit \omega}}{{\mathit \omega}}$ System
 BINON 2005
PAN 68 960 Investigation of the ${{\mathit \eta}}{{\mathit \eta}}$ System in ${{\mathit \pi}^{-}}{{\mathit p}}$ Interactions at a Momentum of 32.5 GeV/$\mathit c$ at the GAMS-4$\pi$ Spectrometer
 ANISOVICH 2000J
PL B491 47 I = 0 C = +1 Mesons from 1920 to 2410 MeV
 ALDE 1998
EPJ A3 361 Study of the ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$ System with the GAMS-4000 Spectrometer at 100 ${\mathrm {GeV/}}\mathit c$
 MARTIN 1998
PR C57 3492 Amplitudes and Resonances from an Energy Dependent Analysis of ${{\overline{\mathit p}}}$ ${+}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}}{+}$ ${{\mathit \pi}}$
 MARTIN 1997
PR C56 1114 Partial Wave Amplitudes and Resonances in ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit \pi}}$
 OAKDEN 1994
NP A574 731 Amplitude Analysis of Data on ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}}{{\mathit \pi}}$ at Low Energy
 ALDE 1990
PL B241 600 Further Study of Mesons which Decay into ${{\mathit \omega}}{{\mathit \omega}}$
 AUGUSTIN 1987
ZPHY C36 369 Radiative Decay of ${{\mathit J / \psi}}$ into ${{\mathit \gamma}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$
 BALTRUSAITIS 1987
PR D35 2077 Radiative Decays of the ${{\mathit J / \psi}}$ into ${{\mathit \gamma}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ and ${{\mathit \gamma}}{{\mathit K}^{+}}{{\mathit K}^{-}}$
 ALDE 1986D
NP B269 485 Production of ${{\mathit G}{(1590)}}$ and other Mesons Decaying into ${{\mathit \eta}}$ Pairs by 100 ${\mathrm {GeV/}}\mathit c$ ${{\mathit \pi}^{-}}$ on Protons
 BINON 1984B
LNC 39 41 Observation a Spin 6 Neutral ${{\mathit R}{(2510)}}$ Meson
 CASON 1982
PRL 48 1316 Amplitude Analysis of the Reaction ${{\mathit \pi}^{+}}$ ${{\mathit \pi}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$ from 1.0 to 2.3 GeV
 ETKIN 1982B
PR D25 1786 Amplitude Analysis of the ${{\mathit K}_S^0}{{\mathit K}_S^0}$ System Produced in the Reaction ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit K}_S^0}$ ${{\mathit K}_S^0}$ ${{\mathit n}}$ at 23 ${\mathrm {GeV/}}\mathit c$
 ALPER 1980
PL 94B 422 Evidence for a Spin-5 Boson Resonance at 2300 MeV
 ROZANSKA 1980
NP B162 505 A Partial Wave Analysis of the ${{\mathit p}}{{\overline{\mathit p}}}$ System Produced at Low Four Momentum Transfer in the Reaction ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit p}}{{\overline{\mathit p}}}{{\mathit n}}$ at 18 GeV
 CORDEN 1979
NP B157 250 An Amplitude Analysis of ${{\mathit \pi}}{{\mathit \pi}}$ Scattering from New Data on the Reaction ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit n}}$
 EVANGELISTA 1979B
NP B154 381 Observation in the ${{\mathit K}^{+}}{{\mathit K}^{-}}$ System of a New Structure at 2.20 GeV
 ANTIPOV 1977
NP B119 45 Boson States in the Reaction ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \pi}^{-}}{{\mathit \pi}^{-}}{{\mathit \pi}^{+}}{{\mathit p}}$ with Leading ${{\mathit \pi}^{+}}$ Meson at 25 ${\mathrm {GeV/}}\mathit c$
 APEL 1975
PL 57B 398 Observation of a Spin 4 Neutral Meson with 2 GeV Mass Decaying in ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$
 BLUM 1975
PL 57B 403 Evidence for a Spin-4 Boson Resonance at 2050 MeV