YN scattering data: AN75

The experiment:

The elastic scattering of Λ on protons is investigated. Λ particles are produced in the interaction of 25 GeV/c protons with the nucleons of a platinum plate which is placed in the 80-inch hydrogen bubble-chamber at Brookhaven National Laboratory. Approximately 220000 pictures are taken and scanned. 109 Elastic scattering events have been found in the 1-17 GeV/c interval. Of these 69 have been used for the final analysis.

The data:

momentum range       number of     SGT [mb]
    [MeV/c]           events

 1000 -  2000           22      22.3 +/- 5.8
 2000 -  3000           16      16.3 +/- 4.8
 3000 -  4000           12      14.4 +/- 4.8
 4000 -  5000            7       7.7 +/- 3.2
 5000 -  6000            4       6.2 +/- 3.3
 6000 - 17000            8       4.1 +/- 1.6

Notes:

• Several corrections have been applied; for the presence of recoil protons too short to be seen; for the cutoff of the Λ-distance from the proton recoil in scattering events; and in the determination of the Λ path-length.
• The cross section for K_S p → K_S p has been determined in the interval 1-9 GeV/c
• The average polarization of the Λ has been determined.
  For Λ momenta < 5 GeV/c, α*P = -0.4 +/- 0.2
  For Λ momenta > 5 GeV/c, α*P = -0.2 +/- 0.4