Charged particle and π0 multiplicity distributions and the annihilation properties ofbar p p interactions at 70 GeV/c
Abstract
The elastic and inelasticbar p p cross sections at 70 GeV/c have been determined in an experiment performed at CERN using BEBC equipped with a TST. The topological cross sections were measured and the moments of the inelastic multiplicity distribution are < n c >=6.16±0.09, < n c >/ D=2.04±0.05 and f {2/ cc }=2.97±0.03. The average number of Dalitz pairs per inelastic event is (3.12±0.09)×10-2. Assuming that these all arise from π0 decay the average π0 multiplicity is< n_{π ^0 } rangle = 2.71 ± 0.14. Thebar p p-pp cross section differences lead to an annihilation cross section σ A = 4.42±0.41 mb and the moments of the annihilation multiplicty distribution are < n A >=8.0±0.3, < n A >/ D=2.5±0.2 and f {2/ A--}=-1.4±0.3. An independent check of σ A was made by investigating fast forward charged and neutral secondary interactions in the TST and in the surrounding neon-hydrogen mixture, and gives a value σ A = 5.0±1.6 mb. The ratio of fastbar n tobar p production in non-annihilation interactions at 70 GeV/c is found to be 0.45±0.11.
- Publication:
-
Zeitschrift fur Physik C Particles and Fields
- Pub Date:
- March 1982
- DOI:
- 10.1007/BF01553626
- Bibcode:
- 1982ZPhyC..13....1D