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STATISTICAL ERRORS ONLY.
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.
No description provided.
A study of π − p → K ∗ Λ and π − p → K ∗ Σ° at 3.9 GeV /c indicates that the main features of both reactions can be interpreted in terms of simple exchange processes, the first involving both natural and unnatural exchange, the second showing evidence for natural parity exchange only.
No description provided.
Antiproton-proton elastic scattering has been measured at 5 GeV/c. A total of 30 000 events were observed in the angular range 17° < θ cm < 136°, corresponding to 0.3 < − t < 7.7 (GeV/ c 2 ). In addition to the known dip at − t = 0.5 ( GeV / c ) 2 , we observe a structure at about − t = 2 (GeV/ c ) 2 and a backward peak with a slope4.1 ± 0.6 (GeV/ c ) 2 . The extrapolated differential cross-section at u = 0 is 1.3 ± 0.8 μ b/(GeV/ c ) 2 .
No description provided.
No description provided.
The elastic scattering of K ± mesons on protons has been studied at 5 GeV/c. A total of about 500 000 events have been measured in the c.m. angular range 17° < θ cm < 165° corresponding to 0.2 < − t < (GeV/ c ) 2 . We observed a K − p backward peak which we have parametrized as d σ /d u = (0.6 ± 0.2) exp [(3.3 ± 0.6) u ] μb /(GeV/c) 2 , while for the K + p backward peak we find d σ /d u = (17.5 ± 1) exp [(3.6 ± 0.2) u ] μb /(GeV/c) 2 . The K − p cross-section falls to about 0.03 μ b ( GeV /c) 2 around − t = 5 (GeV/ c ) 2 , while the K + p cross-section stays in the vicinity of 0.3 μ b ( GeV /c) 2 in the same t -region. The K + p and K − p differential cross-sections have cross-over points at − t = 0.2, 1.1 and about 3.5 (GeV/ c ) 2 .
No description provided.
No description provided.
The differential cross-section for 5 GeV/ cπ + p and π − p elastic scattering have been measured in the c.m. angular region 27° < θ cm < 130° corresponding to 0.5 < | t | < 7.8 (GeV/ c ) 2 . Dips are observed in both reactions at − t = 2.8 and 4.8 (GeV/ c ) 2 where the cross-sections are approximately 0.1 μ b/(GeV/ c ) 2 .
No description provided.
No description provided.
We have analyzed the two-prong final states in π+p interactions at 3.9 GeVc. Our result for elastic scattering is σ (elastic) = 6.50±0.1 mb (statistical error only). We find the elastic slope to be 6.61±0.14 (GeVc)−2. We find the elastic forward cross section to be 40.0±1.4 mb(GeVc)2. We have applied a longitudinal-momentum analysis to the one-pion-production channel. We find the cross section for the reaction π++p→π++π0+p to be 2.30±0.06 mb and that for π++p→π++π++n to be 1.45±0.05 mb. For resonance-production cross sections in these channels we find Δ(1236)=0.60±0.07 mb, ρ(760)=0.86±0.06 mb, and diffraction dissociation = 1.69±0.11 mb. We find that we can satisfactorily fit all distributions in the one-pion-production channel without assuming any phase-space production. In the missing-mass channel we observe dominant Δ++(1236) production plus evidence for A2+ production.
No description provided.
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Proton-proton elastic scattering has been measured over the angular range 7 to 16 mrad at centre-of-mass energies of 31, 45 and 53 GeV using the CERN Intersecting Storage Rings. The results indicate that the diffraction peak has continued to shrink with increasing energy, but not as fast as suggested by the results at lower energies.
No description provided.
Differential cross sections and polarizations have been measured for the reaction π − p → K 0 Λ and π − p → K 0 Σ 0 at 3.9 GeV/ c π − momentum. Comparison of these data with those of the related reactions K − n → π − Λ and K − p → π − Σ + (at approximately the same c.m. energy) indicate that simple Regge-pole models involving only K ∗ (890) and K ∗ (1420) exchange are unable to describe all the features of the data. On the other hand, comparison of the π − p → K 0 Σ 0 data with that of π + p → K + Σ + shows that the data are consistent with absence of exotic strange-meson exchange.
No description provided.
We report on coherent interactions in a 2.5 event/μb K − d exposure. The predominant channel studied is K − d → K − π + gp − d (415 events). We find strong Q- and L-production in the (K ππ ) system. The production mechanism determines I = 1 2 for both enhancements and a spin-parity in the series 0 − , 1 + ,2 − … . A spin-parity analysis shows the Q to be a 1 + object, while the L is 1 + or 2 − , although a higher spin cannot be excluded. The cross sections for Q and L production and other final states are presented.
CORRECTED FOR UNSEEN RECOIL DEUTERONS BY EXTRAPOLATION. (UNCORRECTED CROSS SECTIONS ARE THOSE OBSERVED WITH P(DEUT) > 140 MEV/C).
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