The observation of 70 000 K 0 p π + events produced with K + incident momenta of 1.21, 1.29, 1.38 and 1.69 GeV/ c allows a detailed description of the production and decay of the Δ(1236) and K ∗ (892) resonances which dominate the K 0 p π + final state. No striking variations with energy are observed. The associated production of Δ and K ∗ near threshold shows striking similarities with the same production at higher energy.
INCLUDING 1 PCT SYSTEMATIC ERROR ON CORRECTIONS.
FIT 'A', ALLOWING FOR DELTA-K* INTERFERENCE (TWO OTHER FITS GIVEN IN PAPER).
S-CHANNEL HELICITY FRAME.
We have made a study of the coherent reaction K + d → K 0 π + d at 2 GeV/ c , using data obtained in the Lawrence Berkeley Laboratory 25 inch bubble chamber. The cross section for this reaction is 324 ± 25 μ b, after correction for invisible K 0 decays. This reaction is dominated primarily by vector exchange. We determine the parameters of the ω trajectory to be α ω = (0.33 ± 0.04) + t .
No description provided.
SLOPE IS 9.4 +- 0.5 GEV**-2 FOR -T > 0.02 GEV**2 AND 10.4 +- 0.6 GEV**-2 FOR -TP > 0.
No description provided.
We present the first results of an experiment at the CERN intersecting storage rings, which measures the total cross-section in proton-proton collisions. The equivalent laboratory momenta are 291, 496, 1068 and 1480 GeV/c. We have made a direct measurement of αT as the ratio between the total interaction rate and the machine luminosity. The present paper gives a detailed description of the experimental apparatus and of the analysis procedure. We find that αT increases by about 10% in the energy region studied.
No description provided.
The final results of an experimental investigation of the reaction γ+n→p+π− performed with a deuterium bubble chamber at the 1 GeV Frascati electrosynchrotron are presented. Total and differential cross-sections on neutrons are extracted by means of the spectator model, the reliability of which has been checked by numerous tests and is extensively discussed. The problems of a possible isotensor component in the electromagnetic current, the time-reversal invariance of the electromagnetic interactions and the photoproduction of the Roper resonance are considered in detail.
No description provided.
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The reaction π-p→pωπ- has been studied at 9.1 GeV/c, its total cross-section is σ=(123±22) μb. The pB− and the quasi-three-body channels contribute with cross-section of σ=(24±7) μb and σ=(94±23) μb, respectively. The main features of the quasi-three-body pωπ- channel, displayed by some techniques of data presentation, are satisfactorily described by a double-Regge-pole model. In this model pomeron-meson and meson-meson exchanges are taken into account. An OPE modelà la Veneziano predicts a total cross-section too high and reproduces very poorly the observed features.
BREIT-WIGNER PLUS BACKGROUND FITS FOR B(1235)- AND OMEGA MESONS.
We have measured ρ0, ω (combined) and ϕ electroproduction over a range of virtual-photon four-momentum Q2 from 0.4 to 2.2 GeV2 and for photon energies ν from 2.7 to 8.6 GeV. We find that the slope of the t (momentum transfer) dependence of the ρ0 and ω forward peak decreases with increasing Q2 to less than half of the photoproduction slope.
The cross section for virtual photon are derived from E- P cross section bydividing on the virtual-photon flux factor.
We have measured the mean charged multiplicity n¯CH as a function of transverse momentum p⊥ of the forward proton in the reaction p+p→p+MM for five intervals of missing mass (MM) using our Multiparticle Argo Spectrometer System. We observe an increase of n¯CH for p⊥>1 GeV/c.
No description provided.
The real part of the forward amplitude for Compton scattering on protons was measured through the interference between the Compton and Bethe-Heithler amplitudes by detecting the zero-degree electron pairs asymmetrically. The measurement was made at an average photon energy of 〈k〉=2.2 GeV, and an average momentum transfer to the recoil proton 〈t〉=−0.027 (GeV/c)2. The result confirms the prediction of the Kramers-Kronig relation.
No description provided.
We have measured the cross section, the angular distribution, and the Λ polarization for the reaction π−p→ΛK0. A spark-chamber spectrometer was used to collect 8400 ΛK0 events at fourteen beam momenta near ΣK threshold. Our data do not show the prominent cross-section enhancement suggested by some previous experiments. However, detailed structure in the cross section and the angular distribution agrees well with a simple model which includes a cusp effect at ΣK threshold.
No description provided.
BACKWARD-FORWARD PRODUCTION ASYMMETRY.
AVERAGE LAMBDA POLARIZATION.
The ratio (p¯d→π−π0ps)(p¯d→π−π+n) at rest, with spectator momenta ≲300 MeVc, has been measured and found to be 0.68 ± 0.07. This implies that (75 ± 8)% of the annihilations in deuterium into two pions come from odd N¯N orbital angular momenta, in disagreement with the S-state-dominance hypothesis. It has also been observed that the p¯d→π−π0ps production rate depends on the spectator momentum, which suggests energy-sensitive N¯N phenomena near threshold.
RELATIVE ANNIHILATION FREQUENCY AT REST.