Total and differential cross sections are presented on the reactions: p ̄ p → Λ Λ, ΛΣ 0 + c.c. , Σ + Σ + at an incident momentum of 5.7 GeV/ c , from 200 000 photographs (13 events/ Σ b) of the CERN 2 metre hydrogen bubble chamber. The “forbidden” reaction p ̄ p → Σ − Σ − is also observed and its cross section is 1.3 ± 0.4 μ b. Polarization and correlation of polarizations are presented for the reaction p ̄ p → Λ Λ .
No description provided.
In the reaction p p → 3π + 3π − 2227 events, and in the reaction p p → 3π + 3π − π 0 6578 events have been analyzed. The general characteristics of the reactions, such as total cross sections, angular and momentum distributions, the production of ϱ, f, ω and η mesons, and angular correlations are presented.
No description provided.
THETA being the angle between PI+ and P (or PI- and PBAR) in CMS.
THETA being the angle between PI+ and P (or PI- and PBAR) in CMS.
From a bubble chamber exposure in an antiproton beam at 5.7 GeV/ c yielding 13 events/μb, the final states p ̄ p → Y 1 ∗+ (1385)Λ, Y 1 ∗+ (1385)Σ + , Y 1 ∗+ (1385) Y 1 ∗+ (1385) have been isolated. We have measured the total cross section, d σ /d t , and the complete density matrix of the Y ∗ for these processes. Upper limits have been set to the forbidden reactions p ̄ p → Y 1 ∗− (1385)Σ − , Y 1 ∗− (1385) Y 1 ∗− (1385) .
VALUE OF PRODUCTION CROSS-SECTION IN TEXT HALVED AS INCLUDED CHARGE CONJUGATE REACTION.
VALUE OF PRODUCTION CROSS-SECTION IN TEXT HALVED AS INCLUDED CHARGE CONJUGATE REACTION.
No description provided.
We have studied the process p¯p into π+X− using wire spark chambers. The data cover the angular range of cosθp¯π+* between 0.96 and 1.0 at several incident momenta between 1 and 2 GeVc. The reaction p¯p→π+ρ− was observed with (dσdΩ)* of the order of 100 μb/sr at several momenta.
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Data are presented which firmly establish the existence of the double charge exchange reaction p p → Σ − Σ − at 3.6 GeV/ c . The forward cross section was found to be (5.9 ± 1.1) μb and the ratio of the “forbidden” to “allowed” forward cross section is R = σ( Σ − Σ − σ( Σ + Σ + ) = 0.09 ± 0.02 .
No description provided.
No description provided.
The reactions p p → Λ Λ, Λ Σ 0 or Σ 0 Λ, Σ + Σ + are studied at an incident momentum of 3.6 GeV/ c in a 35.4 event/μb experiment performed in the CERN 2m HBC. Total and differential cross sections are presented. The polarization of the hyperons is measured as a function of t and for the reaction p p → Λ Λ the complete spin correlation matrix is given.
35.4 event/mub data sample used.
35.4 event/mub data sample used.
35.4 event/mub data sample used.
The final states\(\bar p\)pω and\(\Delta ^{ ++ } \bar \Delta ^{ -- } \pi ^0 \), produced in the reaction\(\bar p\)p →\(\bar p\)pπ+π−π0 (6435 events) at 5.7 GeV/c, are studied. Cross-sections are presented, and general features of the resonances produced are investigated. Spin alignment of the ω’s, reported earlier, is studied. An enhancement is observed in the ωp (ω\(\bar p\)) mass plot of mass (1810±15) MeV and width (87 ± 20) MeV.
No description provided.
No definite evidence for structure is found in the p¯p→n¯n cross section between 276 and 963 MeV/c. From these results limits are deduced on properties of the narrow enhancement reported in the p¯p total cross section at 475 MeV/c.
No description provided.
From 63 760 four pronged events we have selected 10 960 events of the p p π + π − final state. We have studied baryon resonances production and the associated production of Δ(1236) Δ (1236) isobars. We find (48.5 ± 2.6)% of Δ ++ Δ ++ and (4.5 ± 0.5)% of Δ 0 Δ 0 . Study of the various mass spectra shows that they are essentially described by the introduction of Δ ++ ( Δ ++ ) production. Introduction of the strong t dependence of the Δ ++ ( Δ ++ ) changes this description only slightly. A study of the interaction radius of the p π system reveals a best value of r = 1.6 ± 0.4 fm. Bumps observed in the p π + π − + c.c. system at 1450 and 1690 MeV when treated as resonances give rates of (4.0 ± 0.4)% and (4.5 ± 0.4)% respectively. We arrive at the conclusion that the reaction p p → p p π + π − at 5.7 GeV/ c proceeds almost entirely via the production of baryon resonances.
No description provided.
No description provided.
Total and annihilation cross sections for p¯p and p¯d have been measured over the momentum range 355-1066 MeV/c at closely spaced momenta and with good energy resolution. No evidence is seen for the narrow structure reported by other experiments in the vicinity of 500 MeV/c. The present measurements indicate a broader enhancement in this region, which, if interpreted as a resonance, would have a height of ∼ 3 mb and a width of ∼ 20 MeV. This structure appears only in the p¯p data.
No description provided.
No description provided.
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