HEPData Search

η′η pair production in the charge exchange reaction π−p→η′ηn has been observed and studied in a search for glueballs with the 38 GeV/c pion beam of the 70 GeV IHEP accelerator. The γ-rays from the decay η′η→4γ were detected with the hodoscope spectrometer GAMS-2000. The η′η events in the mass range from threshold up to 1.8 GeV are decays of the scalar G(1590)-meson which has been already observed in its ηη decay mode. The measured ratio of the partial widths of the G→η′η and the G → ηη decay channels is 2.7±0.8 in agreement with the value expected for glueballs.

1 data table

Table 1

No description provided.

TEST OF QUANTUM ELECTRODYNAMICS IN THE COMPTON SCATTERING OF QUASIREAL PHOTONS BY ELECTRONS AND POSITRONS AT THE VEPP-2M STORAGE RING

Druzhinin, V.P. ; Golubev, V.B. ; Ivanchenko, V.N. ; et al.

Sov.J.Nucl.Phys. 41 (1985) 752, 1985.

Inspire Record 202873 DOI 10.17182/hepdata.37153

None

5 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

Measurement of $\phi$ Meson Radiative Decays at the Storage Ring Vepp-2m With the Neutral Detector

Druzhinin, V.P. ; Golubev, V.B. ; Ivanchenko, V.N. ; et al.

Phys.Lett.B 144 (1984) 136-140, 1984.

Inspire Record 202874 DOI 10.17182/hepdata.6570

Results of the first experiments with the Neutral Detector at the electron-positron storage ring VEPP-2M are presented. Branching ratios of the ø-meson radiative decays have been measured: B ( ø → ηγ )=(1.30±0.06)%, B ( ø → π 0 γ )=(0.130±0.013)%, their accuracy being several times higher than the world average. The width ratio is Γ(ø→ηγ) Γ(ø→π 0 γ)=(10±1) . Using the abovementioned quantities, the ω − ø mixing angle θ v =(38.3±0.2) ° , as well as the ratio between the effective magnetic moments of the s- and u-quarks, μ s μ u =(0.57±0.03) have been calculated.

8 data tables

Table 1

CROSS SECTIONS IN THE PHI MESON PEAK (CORRECTED FOR RADIATIVE EFFECTS).

Table 2

No description provided.

Table 3

SAME AS FIG 2A, BUT KINEMATICAL RECONSTRUCTION ARE APPLIED. I.E. THE ENERGY- MOMENTUM CONSERVATIONS ARE USED TO IMPROVE THE ACCURACY OF PARTICLE ENERGIES AND ANGLES MEASURED IN DETECTOR.

More…

RECENT RESULTS OF EXPERIMENTS WITH THE NEUTRAL DETECTOR AT VEPP-2M

Druzhinin, V.P. ; Dubrovin, M.S. ; Eidelman, S.I. ; et al.

IYF-84-93, 1984.

Inspire Record 202875 DOI 10.17182/hepdata.37143

None

1 data table

Table 1

'AXION' IS NEUTRAL BOSON WHICH HAS MASS < 200 MEV. IT IS ASSUMED THAT NEITHER THIS BOSON NOR THE PRODUCTS OF ITS DECAY ARE DETECTED.

Investigation of the Reaction $e^+ e^- \to \eta \pi^+ \pi^-$ in the Energy Range Up to 1.4-{GeV}

Druzhinin, V.P. ; Dubrovin, M.S. ; Eidelman, S.I. ; et al.

Phys.Lett.B 174 (1986) 115-117, 1986.

Inspire Record 234174 DOI 10.17182/hepdata.30258

The reaction e + e − → ηπ + π − has been studied with the Neutral Detector in the CM energy range 1.05–1.40 GeV at VEPP-2M. At the maximum energy the cross section exceeds the prediction of the vector dominance with one ϱ(770). The following upper limits for the electron width times branching ratio into ηπ + π − have been obtained for a resonance with a mass of 1.28 GeV and width of 0.08 GeV observed with the Omega-spectrometer at CERN: Λ ee · B ηππ < 9 eV, and for a ϱ′(1250) with a mass of 1.26 GeV and width of 0.125 GeV: Λ ee · B ηππ < 14 eV at 90% confidence level.

1 data table

Table 1

Axis error includes +- 10/10 contribution (RES-DEF(RES=ETA,DEF=530<M(2GAMMA)<570 MEV,BACK=CORRECTED)).

A-dependence of $\eta$ Meson Inclusive Production at 10.5-{GeV}/$c$

Bitsadze, G.S. ; Budagov, Yu.A. ; Chirikov-Zorin, I.E. ; et al.

Nucl.Phys.B 279 (1987) 770, 1987.

Inspire Record 231123 DOI 10.17182/hepdata.39482

The experimental results are presented for ratios of ν-meson inclusive differential cross sections in 10.5 GeV/ c π + p, π + D and π + A collisions, R D/p =(d σ /d x F )( π + D → η X)/ (d σ /d x F ) π + p→ η X), R A =(d σ /d x F )( π + D→ η X) in the beam fragmentation region. The results are based on the statistics of ≈ 5 × 10 4 detected η → 2 γ decays. It is shown that the power α in the parametrisation R A ≈ A α ( xf ) does not change significantly with x F and its mean value is 0.50±0.02. The lower limit is obtained for the effective coefficient with string tension in the colour string model, κ ⩾ 3 GeV/fm. The observed growth of R A with x F can be explained by an assumption of a neutron halo with the factor H ≈ 4 in the nuclei.

5 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

2.22-{GeV} $\eta \eta^\prime$ Structure Observed in 38-{GeV}/$c$ and 100-{GeV}/$c \pi^- p$ Collisions

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

Phys.Lett.B 177 (1986) 120, 1986.

Inspire Record 230300 DOI 10.17182/hepdata.40940

A structure has been observed at 2220 MeV in the mass spectrum of ηη ′ systems produced by 38GeV/ c and 100 GeV/ c ′ negative pions on protons. The angular distribution of the decay products shows that this structure is presumably a spin J ⩾ 2 meson.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Date

Collaboration

Subject_areas

Phrases Reset

Observables

CM Energies (GeV)

Authors Reset

MEASUREMENT OF DIFFERENTIAL CROSS-SECTIONS FOR INVERSE PION ELECTROPRODUCTION (PI- P ---> E+ E- N) AT THE PION ENERGY E = 164-MEV. (IN RUSSIAN)

Determination of Nucleon and Pion Form-factors by Analyzing the $\pi^- p \to e^+ e^- \pi$ Reaction at E ($\pi$) = 164-{MeV}

THE RESULTS OF EXPERIMENTS WITH CMD ON VEPP-2M STORAGE RING

Study of $\pi^- p \to \eta^\prime \eta n$ in a Search for Glueballs

TEST OF QUANTUM ELECTRODYNAMICS IN THE COMPTON SCATTERING OF QUASIREAL PHOTONS BY ELECTRONS AND POSITRONS AT THE VEPP-2M STORAGE RING

Measurement of $\phi$ Meson Radiative Decays at the Storage Ring Vepp-2m With the Neutral Detector

RECENT RESULTS OF EXPERIMENTS WITH THE NEUTRAL DETECTOR AT VEPP-2M

Investigation of the Reaction $e^+ e^- \to \eta \pi^+ \pi^-$ in the Energy Range Up to 1.4-{GeV}

A-dependence of $\eta$ Meson Inclusive Production at 10.5-{GeV}/$c$

2.22-{GeV} $\eta \eta^\prime$ Structure Observed in 38-{GeV}/$c$ and 100-{GeV}/$c \pi^- p$ Collisions