We report the results of a study of the reaction p p → p + x at 32.1 GeV c , where the recoiling proton has a small laboratory momentum. The reaction is studied in the 4.5 m Mirabelle bubble chamber at Serpukhov. We compare the diffractive dissociation of the incident antiproton to other incident particles.
No description provided.
CALCULATED USING THE OPTICAL THEOREM AND THE TOTAL CROSS SECTION FOR AP P OF 46 +- 0.3 MB.
The elastic, the pion-production, and the multipion-annihilation cross sections for antiproton-proton interactions at 3.28 and 3.66 BeV/c incident antiproton momenta have been measured. A comparison of the elastic interactions at 3.28 BeV/c with a purely-absorbing disc optical model gave a best value for the radius of interaction of 1.3 F. The real part of the forward scattering amplitude has been found to be less than 20% of the imaginary part. A study of the asymmetries in double elastic scatters yielded a value for a polarizing power of the hydrogen consistent with zero when averaged over production angles.
No description provided.
'1'.
No description provided.
An extensive investigation of antiproton-proton interactions at 5.7 GeV/c without strange-particle production was carried out using a hydrogen bubble chamber. Cross-sections for different channels are given and discussed. The reliability of the analysis was checked using artificially generated events. The cross-sections for elastic scattering, for all processes involving annihilation, and for all other inelastic processes are respectively σel=(16.3±0.6)mb,σannlbil=(22.5±2.0)mb, σinel=(24.8±2.0)mb. TheN * 1:38 is present both in the single and multiple pion production channels. For the reaction MediaObjects/11539_2007_Article_BF02720569_f1.jpg a cross-section of (1.05±0.21) mb was obtained. Cross-sections forN * 1238 production in other channels are also given. Some indication of the presence ofI=1/2 isobars was found in the nucleon-pion and the nucleon-two-pion systems. The inelastic nonannihilation reactions were found to be strongly peripheral. The one-pion exchange model including either a form factor or corrections for absorption was applied to the reaction MediaObjects/11539_2007_Article_BF02720569_f2.jpg . Neither version of the model could correctly account for all features of the reaction. The average number of pions in the annihilation was found to be 7.3±0.6. The presence of an asymmetry in the angular distribution of the charged pions was confirmed at this energy; it is due mostly to high-energy pions. The production of ρ and ω mesons was observed in various annihilation channels. Rates of up to 80% for ρ production and up to 15% for ω production were obtained by fitting phase-space and Breit-Wigner curves to the effective-mass distributions of different channels.
'1'.
No description provided.
No description provided.
Absolute inclusive cross sections for\(\bar pp\) interactions at 7.3 GeV/c are given. The data cover prong cross sections,V0, γ production and inclusive charged particle (p/π) production. Separation has been made into annihilation and non-annihilation components. Inclusive π+, π− production in the processes of\(\bar pp\) annihilation and non-annihilation are compared with simple quark models.
No description provided.
No description provided.
We present new data on charged particle production in p p interactions at 100 GeV/ c . Comparisons are made between p p annihilations (estimated by differences) between corresponding p p and pp data samples) and e + e − annihilation into hadrons. A technique for separating the inclusive proton and pion spectra is described and the resulting pion spectra are studied in terms of Feynman x , rapidity and p T . Comparison with pp data allows us to estimate the pion spectra in p p annihilations and we find agreement with predictions of Mueller-Regge theory. We also present results on semi-inclusive π ± and proton production, give updated topological cross sections and describe further attempts to isolate effects due to annihilations. Finally we investigate the diffractive excitation of the antiproton into low-mass states by studying events with a slow recoil proton.
No description provided.
The small-angle elastic scattering for pp at s=23.5, 30.7, and 52.8 GeV and for p¯p at s=52.8 GeV are measured. The data are normalized on Coulomb scattering. Using the optical theorem and the best estimate of the real part of the forward scattering amplitude, ρ(pp¯)=0.1, we obtain σtot(p¯p)=44.1±2.9 mb for the total cross section and b(p¯p)=13.6±2.2 GeV−2 for the nuclear slope parameter. This supports the dispersion relation prediction that σtot(p¯p) will start to rise above Elab≈200 GeV.
No description provided.
No description provided.
The elastic and topological p¯p cross sections have been measured at 48.9 GeV/c in the Fermilab proportional-wire-chamber-30-in.-bubble-chamber hybrid spectrometer. The elastic cross section is 7.81±0.24 mb and the slope of the elastic differential cross section at t=0 is 13.4±0.8 GeV−2. Further, the moments of the inelastic topological-cross-section distribution are 〈nc〉=5.69±0.03, 〈nc〉D=2.10±0.02, and f2cc=1.67±0.12.
Axis error includes +- 0.0/0.0 contribution (?////DALITZ PAIRS. VEES AND GAMMA CONVERSIONS NEAR THE VERTEX WERE DETERMINED TO BE NEGLIGIBLE. LOW -T ELASTIC EVENTS//ODD-PRONG EVENTS APPARANTLY NOT CAUSED BY SECONDARY INTERACTIONS WERE MOVED TO THE NEXT HIGHER MULTIPLICITY ON THE ASSUMPTION THAT A SHORT TRACK WAS NOTVISIBLETOTAL AP-P CROSS SECTION OF 43.86+-0.25 MB FROM A.S.CARROL ET AL.PRL 33, 928(1974) WAS USED FOR NORMALIZATION).
Forum