[en] This chapter discusses the performances obtained or to be expected from small bubble chambers with ''classical'' optics (i.e. no holography). LEBC and HOLEBC, two hydrogen chambers, are used. The limits on the accessible cross sections, the limits on the accessible life times, the limits on the resolution, and bubble density are considered. In the experiment with the bubble chamber LEBC, two lenses were used of focal length f=180 mm, open at f/11 and with a space to film demagnification m=3.2. In the experiment with HOLBEC, lenses of f=300 mm at f/17 are used with a demagnification m=.9

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[en] This chapter discusses ^-pp annihilation at low energies; the problem of the initial angular momentum state; some other frequencies of two-body annihilations; and analysis of annihilations at rest. The Low-Energy Antiproton Ring (LEAR) will be able to overcome the problems encountered at lower energies with the low available beam intensities and the necessarily smaller target size. Data on ^-pp annihilations in flight can thereby be obtained below 300 MeV/c. The problem of the initial angular momentum state (S or P-wave) in ^-pp annihilations at rest in liquid hydrogen has been intensively investigated. It is concluded that P-wave annihilation is more abundant in D₂ than in H₂ (probably as a consequence of the Fermi motion of nucleons in D₂ which induces P-wave ^-NN annihilation from S-wave orbitals), and a comparison of the rates in H₂ and D₂ demonstrates an upper limit of 6% (at 95% confidence level) to the P-wave contribution to the triplet ^-pp annihilations at rest

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[en] The theoretical uncertainties for the total cross-section and for the function ρ, the ratio of the real-to-imaginary part of the scattering amplitude at zero angle, are discussed. These uncertainties are connected with the spin structure of the panti-p-amplitude. As an example the theoretical uncertainty for the total cross-section is Δσ_tot∼20 mb at p_lab = 181 MeV/c. Different possible solutions for the scattering amplitude, which are in agreement with the existing experimental results are also discussed. These solutions show one rather large P-wave (³P₂ or ³P₁) rapidly varying on a smooth background from the others P-waves and the S-waves

[en] The minimum distance of resolved bubbles in a perfect optical system--with experimental results in not too bad disagreement-does not take into account practical limitations from two sources: the quality of the optical system, and the resulting depth of field. Optical aberrations due to the bubble chamber and vacuum tank windows are studied. The use of an obstructing anular pupil to increase depth of field is considered. The superiority of the holographic method to any classical method, because of its unlimited depth of field, is also discussed

[en] The p-bard interaction at moderate energies is described in Glauber's theory. Experimental data on the cross sections of the p-bard interaction are used to obtain the total and elastic cross sections for scattering of an antiproton by a free neutron

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[en] In an experiment with a 360 GeV/c π^- beam at the CERN SPS using the high resolution hydrogen bubble chamber LEBC and the European Hybrid Spectrometer, an event has been observed of the type πsup(p) → anti D⁰D⁰ + 8 prongs. The fully reconstructed decay modes are D⁰ → K^-π⁺π⁰sub(π)⁰ and anti D⁰ → K⁺π⁺π^-π^-, with all six charged tracks being detected in the spectrometer and all four photons from the π⁰ decays detected in the lead glass gamma detection system. The D⁰ has momentum 119.0 +- 0.6 GeV/c, xsub(F) = 0.31, length 4.1 +- 0.1 mm and proper lifetime (2.1 +- 0.1) x 10^-13 s. The anti D⁰ has momentum 78.5 +- 0.3 GeV/c, xsub(F) = 0.19, length 7.5 +- 0.1 mm and proper lifetime (5.9 +- 0.1) x 10^-13 s. (orig.)