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.
CROSS SECTIONS IN THE PHI MESON PEAK (CORRECTED FOR RADIATIVE EFFECTS).
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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.
Light ion collisions with carbon target at 4.2 GeV/c/N are studied. Pion multiplicity distributions, momentum and angular spectra are analysed. These data are described in terms of models assuming independent interactions of nucleons from the projectile nucleus with the target.
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'AXION' IS NEUTRAL BOSON WHICH HAS MASS < 200 MEV. IT IS ASSUMED THAT NEITHER THIS BOSON NOR THE PRODUCTS OF ITS DECAY ARE DETECTED.
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Axis error includes +- 0.0/0.0 contribution (?////NOT GIVEN).
Axis error includes +- 0.0/0.0 contribution (?////NOT GIVEN).
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The results of the study of the π + p→K + ∑ + (1) and π + p→K + ∑ + (1385) (2) reactions at 12 GeV/ c are presented. The differential cross sections d σ /d t in| t min |<| t |<0.8 (GeV/ c ) 2 momentum transfer range are measured. The ∑ + polarisation for | t |<0.5 (GeV/ c ) 2 for reaction (1) is defined. Binary reactions (1) and (2) were selected by analyzing the missing mass spectra for the forward emitted fast K + meson. The total cross sections in the studied momentum transfer range are 20.2±2.4 μ b and 7.3±1.1 μ b for the reactions (1) and (2) respectively. The experimental results are compared with the predictions of the Regge models which take into account rescattering and secondary singularities.
SYSTEMATIC ERRORS INCLUDED.
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EVENTS HAVE ONE OR MORE CUMULATIVE PIONS.
EVENTS HAVE ONE OR MORE CUMULATIVE PROTONS.
EVENTS HAVE ONE OR MORE CUMULATIVE PIONS AND ONE OR MORE CUMULATIVE PROTONS.
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.
Axis error includes +- 10/10 contribution (RES-DEF(RES=ETA,DEF=530<M(2GAMMA)<570 MEV,BACK=CORRECTED)).
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