Measurement of the anti-p p ---> anti-lambda Lambda and anti-p p ---> Antisigma0 Lambda + c.c. reactions at 1.726-GeV/c and 1.771-GeV/c

Barnes, P.D. ; Franklin, G. ; Quinn, B. ; et al.
Phys.Rev.C 54 (1996) 2831-2842, 1996.
Inspire Record 433023 DOI 10.17182/hepdata.25800

Interest in the production of hyperon-antihyperon pairs following antiproton-proton annihilation stems largely from attempts to understand the nature of flavor production. To date the major focus of both the experimental and the theoretical effort has been on the p¯p→Λ¯Λ reaction. In this paper, we present data on the complementary channels p¯p→Σ¯0Λ and p¯p→Λ¯Σ0. Events from the kinematically similar p¯p→Λ¯Λ reaction were obtained in parallel. The procedure to distinguish these three separate reactions is described and results for all channels are presented. These include the total and differential cross sections, hyperon polarizations, and spin correlation coefficients. Data were obtained at incident antiproton lab momenta of 1.726 and 1.771 GeV/c which correspond to excess kinetic energies in the p¯p→Λ¯Σ0+c.c. reaction of 26 and 40 MeV, respectively, above threshold. Comparisons are made to earlier work at similar excess energies in the p¯p→Λ¯Λ channel. The low-energy regime has been highlighted in this experiment to reduce the complexity in the theoretical analysis. © 1996 The American Physical Society.

7 data tables

No description provided.

Axis error includes +- 2.3/2.3 contribution.

Axis error includes +- 2.3/2.3 contribution.

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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.


Flavor production in anti-p p reactions at low-energies

Eisenstein, Robert A. ;
Phys.Atom.Nucl. 57 (1994) 1680-1692, 1994.
Inspire Record 37436 DOI 10.17182/hepdata.40689

None

4 data tables

No description provided.

No description provided.

No description provided.

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Study of the reactions anti-p p ---> anti-lambda lambda, anti-lambda sigma0 or anti-sigma0 lambda, anti-sigma+ sigma+ at 3.6 gev/c

Atherton, H.W. ; French, B.R. ; Moebes, J.P. ; et al.
Nucl.Phys.B 69 (1974) 1-14, 1974.
Inspire Record 94822 DOI 10.17182/hepdata.32345

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.

4 data tables

35.4 event/mub data sample used.

35.4 event/mub data sample used.

35.4 event/mub data sample used.

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Study of the reaction anti-p p ---> Anti-lambda Lambda below 6-MeV excess energy

Barnes, P.D. ; Birien, P. ; Breunlich, W.H. ; et al.
Phys.Lett.B 331 (1994) 203-210, 1994.
Inspire Record 382628 DOI 10.17182/hepdata.28665

The reaction p p → Λ Λ → p π + pπ − is studied in the experiment PS185 at the CERN Low Energy Antiproton Ring (LEAR). A precise measurement of the excitation function in the immediate threshold region below 6 MeV excess energy was achieved. The total cross section shows an unexpected behaviour around 1 MeV excess energy.

2 data tables

The values are calculated using M(p)=M(pbar) = 938.27231 Mev and M(lambda)=M(lambdabar) = 1115.63 MeV.

D(SIG)/D(OMEGA) as a function of COS(THETA(RF=CM)) for the nine intervals of the excess energy. Excess energy is SQRT(S)-M(lambda)-M(lambdabar).


Study of the reaction anti-p p ---> anti-Lambda Lambda at 1.546-GeV/c and 1.695-GeV/c

Barnes, P.D. ; Diebold, G. ; Franklin, G. ; et al.
Nucl.Phys.A 526 (1991) 575-601, 1991.
Inspire Record 301648 DOI 10.17182/hepdata.36756

The PS185 experiment at the CERN Low Energy Antiproton Ring (LEAR) has studied the reaction p ̄ p → \ ̄ gLΛ at several momenta. In this paper results from two runs with high statistics at 1.546 GeV/ c and 1.695 GeV/ c are described. Based on 4063 and 11362 analysed events, respectively, differential and integrated cross sections, polarizations and spin correlations are presented. The singlet fraction, extracted from the spin correlations, is consistent with zero at both momenta, showing that the \ ̄ gLΛ pairs are produced in a pure triplet state. A comparison of the decay asymmetry parameters of Λ and \ ̄ gL reduces the upper limits for the violation of the CP invariance for this system.

10 data tables

No description provided.

THE BESTFIT WITH LMAX=3, HI2=1.204.

THE BESTFIT WITH LMAX=6, HI2=0.547.

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