A high-statistics experiment on the reaction π − p→ π + π − π 0 n at 8.06 GeV/ c has been performed using a spectrometer detecting both charged particles and gamma rays. A partial-wave analysis based on the isobar model has been carried out for π + π − π 0 data in the mass range between 0.86 and 1.50 GeV for four t ′ regions: 0.0–0.1, 0.1–0.25, 0.25–0.45 and 0.45–0.95 (GeV/ c 2 ). Two axial-vector resonances, a 1 (1260) and h 1 (1170), were observed in the analysis. The masses and widths of a 1 and h 1 were determined to be M (a 1 = 1121 ± 8 MeV, Λ (a 1 = 239± 11 MeV, M (h 1 = 1168±4 MeV and Λ (h 1 = 345±6 MeV, respectively, by fitting the Breit-Wigner formula to the partial wave amplitude. A fit including the Deck type background was also tried in each t ′ region. The results showed a small effect on these resonance parameters and were consistent with those obtained by the simple Breit-Wigner fitting.
Production cross section of A2(1320) from the 12+ rhoD1+ partial wave.
Production cross section of H1(1190) from the 01+ rhoS0+ partial wave.
Production cross section of A1(1270) from the 11+ rhoS1+ partial wave.
Data on the reactions (K+/π+)p→(K+/π+)pπ+π- and (K+/π+)p→(K+/π+)p2π+2π-, obtained with the European Hybrid Spectrometer, are presented and compared with data at lower energies. The contribution of beam and target diffractive dissociation and double Pomeron exchange, and porperties of these reactions are discussed.
No description provided.
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Cross sections or upper limits are reported for 12 meson-baryon and two baryon-baryon reactions for an incident momentum of 9.9 GeV/c, near 90° c.m.: π±p→pπ±,pp±,π+°±,K+Σ±, (Λ0/Σ0)K0; K±p→pK±; p±p→pp. By studying the flavor dependence of the different reactions, we have been able to isolate the quark-interchange mechanism as dominant over gluon exchange and quark-antiquark annihilation.
No description provided.
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Results are presented on π + p and K + p elastic scattering at 250 GeV/ c , the highest momentum so far reached for positive meson beams. The experiment (NA22) was performed with the european hybrid spectrometer. The π + p elastic cross section stays constant with energy while the K + p cross section increases.
No description provided.
No description provided.
ERRORS IN ELASTIC CROSS SECTIONS INCLUDE SYSTEMATIC ERRORS.
The cross section for the production of π+π− or K+K− pairs in γγ interactions is measured for mππ between 1.7 and 3.5 GeV/c2 and for two intervals of γγ center-of-mass scattering angle. Results are compared with predictions of a QCD model.
Data read off graph.
Data read off graph.
Differential cross sections of proton Compton scattering have been measured in the energy range between 400 MeV and 1050 MeV at C.M.S. angles of 150° and 160°.
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The exclusive process π−p→ρ−p has been measured at 90° c.m. with an incident pion momentum of 9.9 GeV/c. We present data on the angular dependence of the decay ρ−→π−π0. We observe a strong azimuthal dependence in the decay in the c.m. helicity frame of the ρ. Such an azimuthal dependence is not compatible with SU(6) valence-quark perturbation calculations.
No description provided.
No description provided.
We have measured the differential cross section for p¯p and pp elastic scattering at s=53 GeV in the interval 0.5<|t|<4.0 (GeV/c)2 at the CERN intersecting storage rings using the split-field magnet detector. The shape of the differential cross section differs significantly between p¯p and pp scattering in the region 1.1<|t|<1.5 (GeV/c)2, with p¯p data showing a less pronounced dip structure than pp data.
No description provided.
No description provided.
We report results from a measurement of the inclusive diffraction dissociation of photons on hydrogen, γp→Xp, in the range 75
4 GeV2. We test the finite-mass sum rule and, by comparing γp with π−p data obtained in the same apparatus, we test factorization.
EXTRACTED ELASTIC CROSS SECTIONS.
EXTRACTED ELASTIC CROSS SECTIONS.
RESULTS OF EXPONENTIAL FITS TO ELASTIC CROSS SECTIONS.
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Axis error includes +- 0.0/0.0 contribution (?////).
Axis error includes +- 0.0/0.0 contribution (?////).
Axis error includes +- 0.0/0.0 contribution (?////).