We have analyzed the two-prong final states in π+p interactions at 3.9 GeVc. Our result for elastic scattering is σ (elastic) = 6.50±0.1 mb (statistical error only). We find the elastic slope to be 6.61±0.14 (GeVc)−2. We find the elastic forward cross section to be 40.0±1.4 mb(GeVc)2. We have applied a longitudinal-momentum analysis to the one-pion-production channel. We find the cross section for the reaction π++p→π++π0+p to be 2.30±0.06 mb and that for π++p→π++π++n to be 1.45±0.05 mb. For resonance-production cross sections in these channels we find Δ(1236)=0.60±0.07 mb, ρ(760)=0.86±0.06 mb, and diffraction dissociation = 1.69±0.11 mb. We find that we can satisfactorily fit all distributions in the one-pion-production channel without assuming any phase-space production. In the missing-mass channel we observe dominant Δ++(1236) production plus evidence for A2+ production.
No description provided.
No description provided.
No description provided.
Results on polarization in π − p and π + p forward elastic scattering at 10, 14 and 17.5 GeV/ c are presented.
No description provided.
No description provided.
No description provided.
Results of a spark chamber experiment on elastic scattering of pions on protons are presented and analyzed. The processes studied were π+p at 2.92 GeV/c, and π−p at 3.15, 4.13, and 4.95 GeV/c. The data are fitted to an exponential function of the four-momentum transfer, t, in several different ways in attempts to explore systematic energy and angular dependences. No shrinkage of the diffraction peak is seen in comparing the coefficients of a linear exponential fit for |t|<0.4 (GeV/c)2; at larger |t|, however, the cross section falls off with increasing energy. The large-angle differential cross section is examined for structure and is compared with all other large angle scattering data. The results are compared with proton-proton scattering data over the same energy range and substantial differences between the two processes are evident.
No description provided.
No description provided.
No description provided.
We measured elastic-scattering angular distributions for π++p scattering at 1.5, 2.0, and 2.5 BeV/c using spark chambers to detect scattered pions and protons. A bump that decreases in amplitude with increasing momentum is observed in the backward hemisphere in the 1.5- and 2.0-BeV/c distributions, but is not observed in the 2.5-BeV/c distributions. It appears reasonable to attribute this phenomenon to the 1.45-BeV/c resonance observed in the π++p total cross section. The data are compared with π−+p data and are found to support the theoretical prediction that the scattering cross sections for both charge states should become equal at high energies. We fit the angular distributions with a power series in cosθ*, and compare the extrapolated values for the scattering cross section in the backward direction with the calculation of the neutron-exchange pole contribution to the cross section. The "elementary" neutron-pole term contribution is calculated to be 90 mb/sr at 2.0 BeV/c, in violent disagreement with the extrapolated value, ≈0.5 mb/sr.
No description provided.
No description provided.
No description provided.
None
No description provided.
No description provided.
Forum