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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