HEPData Search

The invariant mass spectrum of neutral meson states from π − p interactions at 40 GeV/ c incident momentum has been investigated in a high statistics experiment performed at the 70 GeV IHEP accelerator. To detect the high energy photons coming from the produced neutral states, a hodoscope spectrometer with a computer on-line was used. A clear structure on the mass spectrum of dipions produced in the reaction π − p→π°π°n is observed at 2 GeV. The decay angular distributions show in this mass region the variation with mass typical of a state with a spin J = 4. The mass of the observed meson is found to be M = (2020±30)MeV and the estimate of the full width is (180±60) MeV.

1 data table

Table 1

No description provided.

Observation of A Meson x --> 2 gamma, with Mass 2.85-GeV/c**2, Produced in the Charge Exchange Reaction pi- p --> x n at 40-GeV/c

Apel, W.D. ; Augenstein, K.H. ; Bertolucci, E. ; et al.

Phys.Lett.B 72 (1978) 500-502, 1978.

Inspire Record 122151 DOI 10.17182/hepdata.27481

The invariant mass spectrum of neutral final states produced in π − p charge-exchange scattering at 40 GeV/ c has been studied, searching for heavy particles decaying in 2γ. A peak is observed around 2.85 GeV/ c 2 . The cross section of the reaction π − p→X(2.85)+n, times the branching ratio of the X→2 γ decay, is measured to be σ × BR ⋍ 2 × 10 −34 cm 2 .

1 data table

Table 1

MEAN VALUE OF -T = 0.28 +- 0.04 GEV**2.

Evidence for a 1.9-{GeV} Meson Decaying Into $\eta \eta^\prime$

The IFVE-Brussels-Annecy-Los Alamos collaboration Alde, D. ; Binon, F.G. ; Bricman, C. ; et al.

Phys.Lett.B 216 (1989) 447, 1989.

Inspire Record 267048 DOI 10.17182/hepdata.29856

Evidence for a new meson decaying into ηη′ has been found in 38 GeV π − p charge-exchange interactions. The mass and the width of this meson are (1917 ± 15) MeV and (90 −50 +35 ) MeV, respectively. Possible spin and parity assignments are J PC = 0 ++ , 1 −+ or 2 ++ , isospin and G -parity are I G = 0 + . The t -dependence of the differential cross section follows an exponential behaviour exp( bt with a small slope: b = (2±1) (GeV/ c ) −2 .Upper limits on its decay into ππ, ηη and K K exotic interpretation of this meson.

1 data table

Table 1

No description provided.

Study of $\omega \omega$ Systems Produced in 38-{GeV}/$c \pi^- p$ Collisions

The IHEP-IISN-LANL-LAPP-TSUIHEP collaboration Alde, D. ; Binon, F.G. ; Bricman, C. ; et al.

Phys.Lett.B 216 (1989) 451, 1989.

Inspire Record 267049 DOI 10.17182/hepdata.29857

The π − p→ ωω n reaction has studied for the first time at the 70 GeV IHEP accelerator. The six photons from the decay of the two ω mesons were detected in GAMS-2000, a hodoscope multi-photon spectometer. Two resonances decaying into ωω,X (1640) and X(1960), have been observed. Their quantum numbers are J PC =2 ++ , I G =0 + . The reaction is dominated by the one-pion exchange mechanism. The production cross sections σ. BR(X→ ωω ) are 0.65±0.15 μ b and 1.0±0.2 μ b, respectively.

2 data tables

Table 1

X(1640) IS A JPC - 2++, IG - 0+ MESON WITH MASS 1643+-7 MEV.

Table 2

X(1960) IS A JPC - 2++, IG - 0+ MESON WITH MASS 1956+-20 MEV.

Evidence for a 1-+ Exotic Meson

The IHEP-Brussels-Los Alamos-Annecy(LAPP) collaboration Alde, D. ; Binon, F.G. ; Boutemeur, M. ; et al.

Phys.Lett.B 205 (1988) 397, 1988.

Inspire Record 260839 DOI 10.17182/hepdata.29972

A non q q ,J PC = 1 −+ , I G =1 − meson has been observed in the study of the exclusive reaction π − p→π 0 ηn at 100 GeV. Its mass is (1406±20) MeV. Its width is (180±30) MeV.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

NEUTRAL MESONS WHICH DECAY INTO 4 pi0

The Serpukhov-Brussels-Los Alamos-Annecy(LAPP) collaboration Alde, D. ; Binon, F.G. ; Bricman, C. ; et al.

Phys.Lett.B 198 (1987) 286-291, 1987.

Inspire Record 250768 DOI 10.17182/hepdata.30106

Data on the 4π 0 decay mode of mesons have been obtained in a search for glueballs performed at the CERN SPS with the GAMS-4000 multiphoton spectrometer. A new tensor glueball candidate X(1810) appears as a clear peak in the 4π 0 mass spectrum. The 4π 0 decay of G(1590) is also observed. The measured value of BR(G→4 π 0 )/BR(G→ ηη )=0.8±0.3 further supports the glueball assignment of this scalar particle. The rate decay of f(1270) into 4π 0 has been measured: BR(f→4 π 0 ) = (3±1)×10 −3 .

4 data tables

Table 1

No description provided.

Table 2

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Table 3

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Observation of a 1750-{MeV} Narrow Meson Decaying Into $\eta \eta$

The Serpukhov-Brussels-Los Alamos-Annecy(LAPP) collaboration Alde, D. ; Binon, F. ; Bricman, C. ; et al.

Phys.Lett.B 182 (1986) 105, 1986.

Inspire Record 233596 DOI 10.17182/hepdata.30211

A narrow meson which decays into ηη is observed in 38 GeV/ c π − p collisions at large momentum transfer. The experiment has been performed at the Serpukhov accelerator with the GAMS-2000 spectrometer. The mass of this new meson is (1755 ± 8) MeV, its width is less than 50 MeV. Its spin-parity is J PC =0 ++ or less probably 2 ++ .

1 data table

Table 1

No description provided.

OBSERVATION OF AN EXOTIC MESON OF 1.9-GeV MASS DECAYING INTO eta-prime eta

The IFVE-Brussels-Annecy-Los-Alamos collaboration Alde, D. ; Binon, F.G. ; Bricman, C. ; et al.

Sov.J.Nucl.Phys. 48 (1988) 1035, 1988.

Inspire Record 264474 DOI 10.17182/hepdata.40730

None

2 data tables

Table 1

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Table 2

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ANALYSIS OF THE REACTION PI- P ---> PI0 ETA N AT 40-GEV/C BEAM MOMENTUM.

Production of $G(1590)$ in 300-{GeV} Central $\pi^- N$ Collisions

Observation of a Spin 4 Neutral Meson with 2-GeV Mass Decaying in pi0 pi0

Observation of A Meson x --> 2 gamma, with Mass 2.85-GeV/c**2, Produced in the Charge Exchange Reaction pi- p --> x n at 40-GeV/c

Evidence for a 1.9-{GeV} Meson Decaying Into $\eta \eta^\prime$

Study of $\omega \omega$ Systems Produced in 38-{GeV}/$c \pi^- p$ Collisions

Evidence for a 1-+ Exotic Meson

NEUTRAL MESONS WHICH DECAY INTO 4 pi0

Observation of a 1750-{MeV} Narrow Meson Decaying Into $\eta \eta$

OBSERVATION OF AN EXOTIC MESON OF 1.9-GeV MASS DECAYING INTO eta-prime eta