Final states ηΛ and η ′ Λ were studied in K − p interactions at 3.95 GeV c . Cross sections, angular distributions and Λ polarizations are reported. The coupling ration R T = (η 1 K K ∗∗ (1420) (η 8 K K ∗∗ (1420)) M is found to be independent of the momentum transfer. Backward Λη is compared to K − p → Λπ o , π ± p → pπ ± and π − p → nπ o at the same momentum.
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We present the results on total channel cross-sections obtained in the Saclay 180 l HBC exposed to a separated K− beam at Nimrod. The cross-sections for each channel are given at 13 incident K− momenta between 1.26 and 1.84 GeV/c.
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Differential cross sections and density matrix elements are presented for K ∗− (890) and K ∗− (1400) produced in the reaction K − p→K O π − p at 3.95 GeV/ c . The cross sections are decomposed into contributions due to different exchange mechanisms.
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A study is made of η 0 production in p p → 3π + 3π − π 0 (7500 events) at an incident momentum of 720 MeV/ c . The reaction is dominated by production of ω 0 (≈68 o/o). The η o production has been studied by means of two independent methods: the first, a study of correlations between the (4 π ) ± and (5 π ) 0 and the (3 π ) 0 systems, circumvents the problem of ω 0 reflections. The second attempts to isolate the η 0 4π channel by means of rigorous selections using the decay properties of η 0 and ω 0 . The results of the two methods are consistent and confirnm the production of σ +- , D 0 and E 0 with the decays ifD 0 → σ ± π ± → η 0 π + π ( su −), E 0 → σ ± π ∓ → η ( su 0) π + π − , E 0 → η 0 π + π − .
CORRECTED FOR UNOBSERVED ETA DECAYS AND I=0 ASSUMED FOR ETAPRIME, D(1285) AND E(1420) --> ETA PI0 PI0.
The reaction π − p → ηφ has been studied at 1.8 GeV/ c incident pion momentum using the Bologna-CERN NBC set-up, in order to investigate the electromagnetic decay mode φ → ηγ . We observed (27 ± 6) events, yielding a branching ratio Γ(φ → ηγ) Γ(φ → total ) = (7.3 ± 1.9)% . The theoretical implications of this result are discussed.
ASSUMING THE TOTAL PHI CROSS SECTION IS 35 +- 5 MUB, THIS YIELDS THE BRANCHING RATIO OF (7.3 +- 1.9) PCT FOR PHI --> ETA GAMMA.
From a 3.5 ev/μb exposure of the BNL 80 inch chamber filled with deuterium to a 7.0 GeV/ c p beam we obtained 664 events in the channel p n → p π − p . The channel cross section is (1270 ± 110 60 ) μb. The final state is dominated by Δ (1230) production. The experimental data is well described by a one-pion exchange model with off-mass shell corrections.
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As a partial result of an analysis of K + d interactions at 3 GeV/ c produced in the 81 cm Saclay bubble chamber, we present data on K + differential cross sections for the following reactions: K + d → K + d, K + d → K + pn, K + d → K 0 pp . A set of parameters describing the K + n elastic scattering has been obtained from a simulataneous fit, based on the Glauber model. to the three experimental differential cross sections and to the K + d total cross section, giving α n = 1.7 ± 0.5 GeV −2 for the slope α n of the differential cross section, and ρ n = −0.16 ± 0.3 for the ratio of the real to the imaginary part of the forward scattering amplitude. The D-wave function of the deuteron has been found to give a non-negligible contribution to the coherent reaction.
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The reaction pn → pp π − at 7.0 GeV/ c is studied in a pd experiment. Observations on isobar production and low-mass enhancement are reported. The I = 1 2 isobars and the low-mass enhancement produced at the neutron vertex are discussed in terms of the diffraction dissociation plus duality model.
PART OF THE DIFFERENCE BETWEEN DEL PRODUCTION AT THE NEUTRON AND AT THE PROTON VERTICES COULD ARISE FROM DEUTERON EFFECTS.
We present results on the differential cross sections for the process K + n → K 0 p extracted from the reaction K + d → K 0 pp measured at 13 momenta between 0.64 and 1.51 GeV/ c .
THESE TOTAL CROSS SECTIONS WERE PRESENTED WITH MORE EXPERIMENTAL DETAILS IN G. GIACOMELLI ET AL., NP B37, 577 (1972).
REACTION HAS A SPECTATOR PROTON. THESE ARE NOT FREE NEUTRON CROSS SECTIONS. A 250 MEV/C MOMENTUM CUT IS APPLIED TO THE SPECTATOR MOMENTUM AND D(SIG)/DOMEGA THEN NORMALIZED TO THE UNCUT TOTAL CROSS SECTION FOR K+ DEUT --> K0 P P.
Final results for 3678 six-prong π+p events at 8 GeV/c are presented. Single-particle distributions are compared with the predictions of the Chan-Loskiewicz-Allison model and the phenomenological model of the F(t) function. Differences between the transverse momenta of the π+ and π− and between the transverse momenta of secondaries emitted forward and backward in the c.m. system are observed. Cross sections for production of the ρ0, ρ+, ρ−, η, ω0, X0, and D0 mesons and the N33*++ and N33*− isobars are given, together with upper limits for some other resonances. The D0 meson is observed in the seven-body channel in the ηπ+π− system, with some evidence for the cascade decay D0→δ±π∓→ηπ+π−. The branching ratio (f0→2π+2π−)(f0→2π) is determined to be (2.2−2.2+4.5)%. Upper limits for the decay of A mesons into X0π systems are quoted. The cross section for the two-body reaction π+p→N33*++X0 is determined to be 30 ± 13 μb, from which the η0−X0 mixing angle is derived. Associated production of N33*++ and ρ0 in the six-body channel and of N33*++, ρ0, and ω0 in the seven-body channel is studied, and the cross sections for reactions involving simultaneous production of these resonances are estimated. The Goldhaber-Goldhaber-Lee-Pais effect is studied and shown to be strong in the six-body channel, especially for selected events with low energy of the pion system.
TOTAL NUMBER EVENTS=504. DATA FROM T 1.
TOTAL NUMBER EVENTS=1075. DATA FROM T 1.
TOTAL NUMBER EVENTS=425. DATA FROM T 1.