Data are presented on the production of the KN π final states in K + p interactions at 7.3 GeV/ c . The energy dependence of the KN π final state cross sections, the effective-mass distributions, and the spectra of c.m. longitudinal momenta are given, and features of these data are compared with predictions of the generalized Veneziano (GV) model. Furthermore, we present the momentum transfer and decay angular distributions for K ∗ (890), K ∗ (1420) and Δ (1236) production within the KN π final states and discuss these quasi-two-body reactions in terms of the GV model.
BREIT-WIGNER RESONANCE FITS WITH BACKGROUND CONTRIBUTION.
No description provided.
No description provided.
The ratio R = (d σ /d t )( γ d → ( π 0 n)p)/(d σ /d t )( γ d → ( π 0 p)n), was measured at the Deutsches Elektronen-Synchrotron DESY, Hamburg at a mean photon energy of 4.0 GeV in the four-momentum transfer range between t = − 0.2 (GeV/ c ) 2 and t = − 1.2 (GeV/ c ) 2 in steps of approximately 0.08 (GeV/ c ) 2 . The ratio R is less than 1 up to t = − 0.9 (GeV/ c ) 2 and shows a broad minimum around t = − 0.6 (GeV/ c ) 2 . Corrections for nuclear effects in the deuterium were not applied but are shown to be small.
No description provided.
We have studied high-energy proton scattering on Be, C, Cu and Pb targets using a single-arm spectrometer. The projectile momenta were 19 and 24 GeV/ c , the square of the four-momentum transfer varied from t = 0.1 to t = 4.4 GeV 2 . We have recorded momentum distributions of scattered protons in the high-momentum range. An application of multiple-scattering theory yielded agreement of calculation and experimental results to within a ± 30% uncertainty of the former.
X ERROR D(OMEGA) = 0.0076 MSR.
X ERROR D(OMEGA) = 0.0076 MSR.
X ERROR D(OMEGA) = 0.0076 MSR.
The electroproduction of a π-meson and of a Δ(1236) nucleon resonance on hydrogen, ep → e πΔ (1236), was investigated in the two charge states π − Δ ++ and π + Δ 0 by measuring the scattered lepton and the produced π-meson in coincidence. The differential cross sections as funcions of W , q 2 , t − t min and ø πq were determine in the following kinematical region: w = (π + δ) 2 = 2.0 − 3.0 GeV , |q 2 | = |(e−e′) 2 | = 0.15 − 0.8 GeV 2 /c 2 , |t − t min | = 0-0.5 GeV 2 /c 2 with t = ( p − δ) 2 , φ πq = 0 − 360° .
W-DEPENDENCE FOR 4.0 GEV INCIDENT POSITRONS.
W-DEPENDENCE FOR 4.9 GEV INCIDENT POSITRONS.
W-DEPENDENCE FOR 5.4 GEV INCIDENT POSITRONS.
The differential cross section of the reaction γ p → π 0 p has been measured at the Deutsches Elektronen Synchrotron DESY, Hamburg, at a mean photon energy of 4.0 GeV in the four-momentum transfer range between t = −0.2 (GeV/ c ) 2 and t = −1,2 (GeV/ c ) 2 in steps of approximately 0.08 (GeV/ c ) 2 . The experiment was carried out in connection with the measurements of the photoproduction of π 0 mesons on deuterium, which were described in the preceding article. In the present paper the contributions arising from background reactions are discussed in more detail.
No description provided.
For the reaction π + p → ωΔ ++ data on the total cross section ( σ = 61 ± 12 μ b), differential cross sections, spin density matrix elements and statistical tensor elements are given. We observe natural and unnatural parity exchange contributions to the total cross section. We note that the value of ϱ 00 is not zero and in the helicity frame exhibits a dip at t ≈ −0.25 (GeV/ c ) 2 . A qualitative theoretical discussion of our results is presented.
CORRECTED FOR BACKGROUND, RESONANCE TAILS AND UNSEEN OMEGA DECAY MODES.
NORMALIZED TO THE TOTAL CROSS SECTION. SOME BACKGROUND IS PRESENT.
NORMALIZED TO THE TOTAL CROSS SECTION. SOME BACKGROUND IS PRESENT.
A bubble-chamber study is presented of a 10 events/μb experiment using K − mesons of 4.25 GeV/ c incident momentum. Differential and total cross sections are determined for 7 different reactions: K − p → K 0 n ( la ), → π 0 Λ ( lb ), → ηΛ ( lc ), → η′Λ ( ld ), → π − Σ ( le ), → π + Σ − ( lf ), K + Ξ − ( lg ) . The experimental characteristics in d σ /d t of each reaction are described: (la) shows a levelling off at t = 0 (GeV/ c ) 2 , a break at t = −0.6 (GeV/ c ) 2 and no backward events, (lb) d σ /d t has a smooth behaviour and a measurable backward component with an indication of a dip at u = −0.2 (GeV/ c ) 2 , (1c) d σ /d t shows a dip in the region between t ≈ −0.2 and −0.4 (GeV/ c ) 2 , (ld) d σ /d t has a smooth behaviour; neither this reaction nor the preceding one shows a clear evidence for backward events, (le) d σ /d t has a break at t = −0.5 (GeV/ c ) 2 ; there is a significant cross section in the backward region; (lf) and (lg) show mainly backward production. The polarization of the hyperon is measured in the reactions (lb), (lc), (ld) and (le) in the forward production peak. The statistics do not allow the detection of a definite structure in the polarization but the sign and magnitude are determined. An interpretation of the results is given in terms of a dual Regge model, including the effects of absorption as elaborated recently by several authors.
No description provided.
No description provided.
No description provided.
We have measured the K − p elastic-scattering differential cross section at 3.59 GeV/ c for t < −0.1 (GeV/ c ) 2 . After all geometrical and kinematical cuts we have 11 734 elastic events. The forward diffraction peak has a slope of 7.57 ± 0.1 (GeV/ c ) −2 , and there is a marked dip-bump structure at t ∼ −1.0 (GeV/ c ) 2 . The elastic cross section is 4.4 ± 0.2 mb. There is no evidence for a backward peak.
No description provided.
EVENTS NORMALIZED TO A TOTAL CROSS SECTION OF 26.3 +- 0.3 MB.
The reaction K − p → X K − p has been measured at 25 and 40 GeV/ c at the Serpukhov accelerator using the CERN-IHEP boson spectrometer. At both energies we observe production of the resonances K ∗− (890) and K ∗− (1420) in the channels K ∗− → K 0 π − and K − π 0 ; the momentum dependence of their production cross sections is found to be σ[ K ∗− (890)] ∞ p inc −1.48±0.04 and σ [ K ∗− (1420)] ∞ p inc −0.8±0.2 .
No description provided.
No description provided.
No description provided.
The neutron-proton elastic differential cross section has been measured with high statistics for incident momenta between 10 and 24 GeV/ c using wire spark chambers for the neutron detection. The t -range covered by previous experiments could thus be extended to 0.06–3 (GeV/ c ) 2 . In this t -interval the np cross section is found to be very similar to the corresponding pp cross section.
No description provided.
No description provided.
No description provided.
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