Measurement of the reactions anti-p p ---> Antisigma+ Sigma+ and anti-p p ---> Antisigma- Sigma- close to threshold

The PS185 collaboration Barnes, P.D ; Breunlich, W ; Dennert, H ; et al.
Phys.Lett.B 402 (1997) 227-236, 1997.
Inspire Record 457944 DOI 10.17182/hepdata.28302

The reactions p p → ∑ + ∑ + and p p → ∑ − ∑ − have been investigated at GeV/c beam momentum by the PS185 Collaboration at LEAR, CERN. Of both reaction types together 170 events could be identified. The cross section of the reaction p p → ∑ + ∑ + was determined to be σ tot = 3.68 ± 0.43 μ b at an excess energy of 23 MeV. Its angular distribution exhibits a pronounced forward peaking. The ratio of the cross sections σ( p p → ∑ + ∑ + ) σ( p p → ∑ − ∑ − ) = 2.4 −1.3 +3.0 was extracted with a confidence limit of 90%. It is the first time that experimental data of these reaction channels are available close to the threshold. We compare our results with those of earlier experiments and with theoretical predictions.

1 data table

No description provided.


Two-body hyperon production by 5.7 gev/c anitprotons on protons

Atherton, H.W. ; Celnikier, L.M. ; French, B. ; et al.
Phys.Lett.B 30 (1969) 494-497, 1969.
Inspire Record 56634 DOI 10.17182/hepdata.28892

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 .

1 data table

No description provided.