Cross sections and decay distribution moments are presented for the reaction p p → Δ ++ Δ ++ at 3.6 GeV/ c , and compared with previously published data at 9.1 and 12 GeV/ c . With the aid of the quark model, we have isolated the natural and unnatural parity exchange contributions and shown them to accord with expectations based on simple Regge-pole exchanges.
DOUBLE RESONANCE PRODUCTION IS 62 +- 2 PCT OF CHANNEL.
DIFFERENTIAL CROSS SECTION INTERCEPT AND SLOPE. EVENT SAMPLE DEFINED BY CUTS ON LONGITUDINAL PHASE SPACE PLOT.
No description provided.
We have studied the reaction π − p → X − p followed by the decay X − → ωπ − at 11.2 GeV/ c . The partial-wave analysis in the mass range 1.36–2.0 GeV shows a clear structure in the J P = 3 − , m = 0 wave peaking at 1.67 GeV with a width of ∼0.21 GeV. We interpret this result as resulting from the g → ωπ decay. The differential cross section d σ d t is in agreement with the production of the g-meson through one-pion exchange.
FROM BREIT-WIGNER FIT TO <OMEGA PI-> MASS SPECTRUM. CORRECTED FOR OMEGA TAILS AND OTHER DECAY MODES. CROSS SECTION ORIGINALLY GIVEN IN R. GESSAROLI ET AL., NP B126, 382 (1977).
No description provided.
No description provided.
The reactions p p → K ∗ (890) X , p p →Σ ± (1385) X and p p → S ∗ (993) X at 12 GeV/ c incident momentum have been studied using 19 000 events with a visible V 0 decay in BEBC. Inclusive production cross sections of these resonances as a function of transverse momentum and rapidity are presented. The contribution of annihilation to the production of the K ∗ (890) is investigated from a comparison with the corresponding pp data.
COMBINDED K*+ AND K*- DATA IN THIS TABLE.
COMBINDED K*+ AND K*- DATA IN THIS TABLE.
No description provided.
A strong negative transverse polarization P z is found for forward produced lambdas observed in 10 and 16 GeV/ c K − p interactions. This indicates that exchanges of natural spin-parity are dominant in the production process. Using the polarization results, the d σ d u′ distributions for natural and unnatural spin-parity exchanges are derived. For unnatural exchanges, a dip is observed at u ′≅0.3 GeV 2 , which can be explained as a nonsense-wrong-signature zero of the N β trajectory. The value of P z for forward producted lambdas is constant with energy. This is in agreement with the triple-Regge model prediction, as is the fact that P z is constant as a function of M 2 s . The two non-transverse polarization components, P x and P y , have been measured and are found to be consistent with zero for all x values, unlike P z .
No description provided.
No description provided.
No description provided.
At the Bonn 2.5 GeV synchrotron the polarization of the Λ 0 was measured at 40° and 90° for three energies. The kaon was detected with a strong focussing magnetic spectrometer and separated from other particles with the help of a differential liquid Čerenkov counter. The polarization was determined by means of the angular distribution of the decay proton which was measured with a combination of sonic spark chambers and a scintillation counter hodoscope. The typical statistical errors are about 13%. The systematic errors add up to 8%.
No description provided.
Single-pion production in p p interactions at 9.1 GeV/ c is analysed and cross sections are given. The p lab dependence of the isospin amplitudes is determined by a fit to the world data. The data are also compared with the predictions of a reggeized Deck model. The results and the N π N amplitudes are compared with the results at other energies and with the corresponding N π N amplitudes.
MEASUREMENTS FROM OTHER EXPERIMENTS DOWN TO PLAB = 1 GEV ALSO QUOTED.
No description provided.
The production of the φ and ω mesons has been studied in the reactions p p → φ(ω)π + π − and p p → φ(ω) ϱ 0 at 0.70–0.76 GeV /c . The c.m. angular distribution of the φ meson in the reaction p p → φπ + π − is found to be consistent with isotropy. The corresponding distribution for ω is not. the ratio σ( p p → φπ + π − ) σ( p p → ωπ + π − ) is (10 ± 2.4) · 10 −3 , which leads to a value of (19 ± 5) · 10 −3 when corrected for the phase-space factor. Implications of this result for the OZI rule are discussed.
No description provided.
No description provided.
Cross sections for various channels in 3 prong + V 0 final states of K − n interactions are obtained at 8.25 GeV/ c . An energy dependence study of the quasi two-body reactions Σ − (1385) + vector meson and ΛB − seem to imply the presence of cuts in the Regge exchange formalism, whereas the reaction Δ(1236) K ∗ (890) does not require such cuts. Upper limits of 1 and 2 μb are found for the reactions K − n → Λ A 1 and K − n → Λ A 2 .
CROSS SECTIONS ARE CORRECTED FOR ALL RESONANCE DECAY MODES EXCEPT FOR K*- DEL0 PRODUCTION WHICH IS ONLY CORRECTED FOR UNSEEN AK0 DECAYS. NO EVIDENCE FOR NON-DIFFRACTIVE A1 AND A2 PRODUCTION.
MAXIMUM LIKELIHOOD EXPONENTIAL FITS TO DIFFERENTIAL CROSS SECTIONS.
Measurements of the total cross section have been performed at the ISR with c.m. energies between 23.5 GeV and 62.5 GeV. Two independent experimental methods have been applied, a measurement of total interaction rate and of small angle elastic scattering. Both experiments give consistent results showing that the total cross section increases by (11.8±1.5) % over the ISR energy range. This experiment has also measured the slope of the forward diffraction peak in elastic scattering at small momentum transfer. The elastic cross section shows the same relative rise as the total cross section, and the ratio λ of elastic to total cross section approaches a constant value of λ =0.178±0.003.
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TOTAL CROSS SECTION FROM (INTERACTION RATE)/(LUMINOSITY). SYSTEMATIC ERROR <0.8 PCT.
TOTAL CROSS SECTION FROM APPLYING THE OPTICAL THEOREM TO SMALL ANGLE ELASTIC SCATTERING EXTRAPOLATED TO T=0.
We have investigated the reactions p p π + π − a ̊ and p p a ̊ p p 2π + 2π − at 100 GeV /c . The p p π + π − final state is dominated by diffractive production of a p π + π − ( or p π + π − ) system which shows a strong tendency to form Δ ++ π − ( or Δ ++ π + ) . The process p p a ̊ Δ ++ Δ ++ is also observed in this reaction, indicating an energy dependence of s −1.5±0.1 . The p p 2π + 2π − channel shows less single diffraction, and has a doubly diffractive component consistent with pomeron factorization. Strong Δ ++ ( Δ ++ ) production is agoain seen, but in contrast to the p p π + π − channel we also observe considerable ϱ 0 production.
No description provided.
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