Results are reported based on a study of π − p interactions at 147 GeV/ c in the FERMILAB 30-inch Proportional Wire Hybrid Bubble Chamber System. We have measured the topological cross sections and separated two-prong elastic and inelastic channels. In addition, we have extracted leading particle cross sections using the increased momentum resolution of the downstream proportional wire chambers. We have compared our results with experiments and predictions of a simple fragmentation hyphothesis.
No description provided.
The differential cross section has been measured for the reaction γ +p→ π o + p at the Bonn 2.5 GeV electron synchrotron in the energy range from 0.55 to 2.2 GeV at a c.m.angle of 120 degrees.
No description provided.
The reaction e − + p → e − + p + η has been studied in the region of the S 11 (1535)-resonance by detecting the recoil proton in coincidence with the scattered electron. The reaction has been observed at three four-momentum transfers of the virtual photon: q 2 = 0.2, 0.28 and 0.4 (GeV/ c ). First results of the differential cross section measurements are given and compared with quark model calculations.
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The ratio between the cross sections for the reactions π − p→ χ ↳ 2γ 0 n and π − p → η →2 γ n has been measured to be (2.4 ± 0.9) × 10 −2 , (2.1 ± 0.6) × 10 −2 and (2.8 ± 1.3) × 10 −2 at 3.8,6,8 and 12 GeV/ c incident momentum respectively.
ETAPRIME CROSS SECTIONS DEDUCED FROM THEIR RATIO TO ETA PRODUCTION, USING THE RESULTS OF O. GUISAN ET AL., PL 18, 200 (1965).
Channel cross sections have been determined for p p annihilations into final states containing 3 to 9 pions at 4.6 GeV/ c . The moments of both the charged and neutral pion multiplicity distributions are presented and model predictions are critically examined.
No description provided.
The reaction e − + p → e − + p + π 0 has been studied in the region of the Δ (1236) resonance at a four-momentum transfer of the virtual photon of 0.3 (GeV/ c ) 2 . Angles and momenta of the secondary electron and of the outgoing proton were measured in coincidence to obtain the angular dependence of the differential cross section. The angular distribution for s- and p-waves of the pion in the πN cm-system was fitted to the cross section for three W -bins around the maximum of the resonance. The contribution of the resonant multipoles M 1+ , E 1+ and S 1+ to the cross section as well as the contribution of the background amplitudes M 1− , E 0+ and S 0+ are given.
No description provided.
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Photoproduction of π + and π − on deuterium has been measured in the photon energy range from 240 to 400 MeV and for pion c.m. angles between 15° and 180°. The pions were analysed in angle and momentum by a magnetic spectrometer. From the measured π − / π + ratio, corrected for Coulomb interactions in the final state, differential cross sections of the reaction γ +n→ π − +p were calculated. Together with the π + photoproduction our data show no isotensor contribution. Comparison of our data with the recent experiments done on the inverse reaction shows no evidence of a violation of time reversal invariance. With the measured π + photoproduction on deuterium, a test of the spectator model has been made. Using the closure-approximation of Chew and Lewis our data agree within a range of ±10%.
No description provided.
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Bubble chamber film of 10 GeV/ c K − p interactions was scanned automatically by an H.P.D. to look for small angle scatters in the | t |-range from 0.008 to 0.1 GeV 2 . Combining the 1800 events so obtained with 22 000 elastic events obtained from normal scanning (| t | > 0.06 GeV 2 ), the real part of the elastic scattering amplitude was found to be (+25 ± 10)% of the imaginary part. Evidence is found for a change in slope in the differential cross-section distribution, from 9.8 ± 0.6 GeV −2 in the | t |-range below 0.1 GeV 2 to 7.1 ± 0.2 GeV −2 in the range 0.12 < | t | ⩽ 0.4 GeV 2 .
No description provided.
THE 10 PCT ERROR IS THE RESULT OF A 5 PCT ERROR FROM THE FIT AND AN 8 PCT NORMALIZATION UNCERTAINTY.
No description provided.
The polarization parameter in π − p elastic scattering has been measured in the backward angular region at an incident momentum of 6 GeV/ c . The measurements cover the range of four momentum transfer u = 0 to −1 (GeV/ c ) 2 , and were obtained with a high intensity pion beam, a butanol polarized proton target, and arrays of scintillation counter hodoscopes. The polarization is different from zero, in contradiction to the prediction of the naive one trajectory Regge-exchange model. It increases positively with the four-momentum transfer u, reaching a maximum of about 0.4 at u ≈ −0.3 (GeV/c)2. It then decreases and becomes slightly negative beyond u ≈ −0.5 (GeV/c)2. A variety of baryon exchange models are briefly reviewed and none are found to be in complete agreement with all the experimental data.
No description provided.
The π − p→n γ and π − p→n π ° differential cross sections have been measured for −0.9< cos θ ∗ <−0.45 (θ ∗ c.m. scattering angle) at 475 MeV/ c and 550 MeV/ c incident momenta. The π − p→n γ measurement is a good check of the detailed balance principle in the electromagnetic interactions of hadrons at these energies and is in good agreement with Walker's analysis. On the other hand the π − p→ π °n extrapolated values of 180° allows one to verify that the phases of the A 1 2 and A 3 2 amplitudes are equal.
No description provided.
No description provided.
BACKWARD CROSS SECTION ESTIMATED BY LEGENDRE POLYNOMIAL FIT.
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