HEPData Search

Showing 10 of 38 results

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.

Anti-proton charge exchange on protons at 25 and 35 gev/c

Bolotov, V.N. ; Isakov, V.V. ; Kakauridze, D.B. ; et al.

Nucl.Phys.B 73 (1974) 401-409, 1974.

Inspire Record 94654 DOI 10.17182/hepdata.32275

Cross sections for p ̄ p → n ̄ n at 25 and 35 GeV/ c have been measured. The cross sections decrease with increasing momentum as 1/ P 2 . A narrow peak is observed in the momentum transfer interval 0 ⩽ − t ≲ 0.02 (GeV/ c 2 in the differential cross sections. Neither ϱ nor A 2 exchange contribute to the process in the investigated energy range.

3 data tables

Table 1

K- CEX MEASURED BY STARS FROM KL AS A CHECK.

Table 2

No description provided.

Table 3

No description provided.

Negative pion charge exchange scattering on protons in the momentum range 20-50 gev/c

Bolotov, V.N. ; Isakov, V.V. ; Kachanov, V.A. ; et al.

Nucl.Phys.B 73 (1974) 365-386, 1974.

Inspire Record 94656 DOI 10.17182/hepdata.32247

Differential cross sections for charge exchange π − p → π 0 n have been measured for momenta up to 50 GeV/ c . The cross section falls as a power of energy. The forward scattering cone shrinks with increasing energy. The cross section for charge exchange at zero angle drops with momentum as P −0.81±0.05 . The charge exchange cross section in the region of the second maximum decrease as P −2.8±0.1 . The ϱ trajectory is described by a linear function α ( t ) = 0.56 + 0.97 t in the interval 0 < − t -<1.5 (GeV/ c ) 2 .

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Reaction pi- p ---> eta0 n at momenta up to 50 gev/c

Bolotov, V.N. ; Isakov, V.V. ; Kakauridze, D.B. ; et al.

Nucl.Phys.B 73 (1974) 387-400, 1974.

Inspire Record 94655 DOI 10.17182/hepdata.32318

Differential cross sections for π − p → η 0 n, η 0 → 2 γ have been measured from 20 to 50 GeV for four-momentum transfers − ≲ 3 (GeV/ c ) 2 . The cross sections decrease as a power of momentum and the forward scattering cone shrinks slowly. The parameters of the A 2 trajectory, which is considerably non-linear, have been determined.

2 data tables

Table 1

No description provided.

Table 2

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.

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

The Serpukhov-CERN collaboration Apel, W.D. ; Augenstein, K. ; Bertolucci, E. ; et al.

Phys.Lett.B 57 (1975) 398, 1975.

Inspire Record 99595 DOI 10.17182/hepdata.27849

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.

Measurement of the cross-sections for reaction pi- p ---> x0 n in the momentum range up to 50 gev/c

Bolotov, V.N. ; Isakov, V.V. ; Kachanov, V.A. ; et al.

Phys.Lett.B 48 (1974) 280-284, 1974.

Inspire Record 95354 DOI 10.17182/hepdata.27969

The cross sections for the reaction π − p → X o n, X o → 2 λ are measured at 32.5 and 48 GeV c momenta. The cross spectrometer of γ -quanta is used to select events of reaction, whose cross section is only about 0.05 μbarn. The cross section energy dependence has the power form ( ≈ p −1.11±0.12 . conclusion on U(6) symmetry of quark model is made when comparing the differential cross sections at zero angle for the reactions π − p → X o and π − p → η o . The angle of octet-singlet mixing for pseudo-scalar mesons β = −(20.6 ± 2.2)° is defined.

2 data tables

Table 1

FROM AVERAGE OF 32.5 AND 48 GEV/C DATA.

Table 2

No description provided.