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No description provided.
In a study of photoproduction at photon energies up to 5.3 GeV in a deuterium bubble chamber the reactions γ n→p π + π − π − and γ n→p π + π − π − π 0 were analyzed. In these reactions production of the resonances Δ ++ , Δ 0 , ϱ 0 , ω and A 2 − was observed. Photoproduction of strange particles was investigated and cross sections for the reactions γ n→ Λ K + π − , Σ − K 0 π + , pK − K 0 , Λ K 0 π + π − and Λ K + π − π 0 are presented. Production of Σ − (1385) and K ∗0 (890) was observed.
No description provided.
No description provided.
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The differential cross section has been measured for the reaction γ +p→p+ π o at the Bonn 2.5 GeV electron synchrotron in the energy range from 0.4 to 2.2 GeV for a c.m. angle of 150 degrees. The protons were detected in a magnetic spectrometer system. The excitation curve shows a distinct resonance structure. The total corrections to the counting rate are about 3%. The contribution of the process γ +p→p+2 π was separated. The uncertainty of this separation leads to an error of about 4% in the cross section.
No description provided.
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 target asymmetry T = ( σ ↑ − σ ↓)/( σ ↑ + σ ↓) for the reaction γ p → π + n has been measured at the Bonn 2.5 GeV electron synchrotron for a pion c.m. angle of 40° and γ energies between 0.5 and 2.2 GeV. Butanol was used as the target material. About 35% of the protons could be polarized using the dynamic-polarization method in a continuous-flow cryostat operating at 1°K and 25 kG. The π + mesons were detected in a magnetic-spectrometer system. Considerable structure in the asymmetry was observed.
Axis error includes +- 11/11 contribution.
Total and differenial cross sections of the reaction γ +n→p+ π − have been determined for photon-energies between 0.2 and 2.0 GGeV. Below 500 MeV the differential cross sections are compared with theoretical predictions derived from fixed-momentum-transfer dispersion relations.
Axis error includes +- 0.0/0.0 contribution (5 TO 8////).
Axis error includes +- 0.0/0.0 contribution (5 TO 8////).
Axis error includes +- 0.0/0.0 contribution (5 TO 8////).
For the reaction γ p → K + Λ 0 the differential cross section has been measured at t = −0.147 GeV 2 ( θ C.M. = 26.5 ± 3.5°) and photoenergies between 1.05 and 2.2 GeV and for the reaction γ p→K + Σ 0 at ≈−0.17 GeV 2 ( θ C.M. = 28±3.5°) and photoenergies between 1.3 and 2.2 GeV. For this four momentum transfer the differential cross section of K + Λ 0 photoproduction has a surprising steep increase above threshold and stays nearly constant up to 2.2 GeV. The K + Σ 0 cross section increases from 1.3 to 1.56 GeV and goes down gradually at higher energies.
AT CONSTANT MOMENTUM TRANSFER OF -T = 0.147 GEV**2.
AT APPROXIMATELY CONSTANT MOMENTUM TRANSFER OF -T = 0.17 GEV**2.
We present results for the reactions K 0 p →Λπ + and K 0 p →∑ 0 π + , for |u'| <0. 05 ( GeV /c) 2 and kaon momenta between 1 and 8 GeV/ c . The experiment was performed ina neutral beam at the PS with a two arm spark chamber spectrometer. The cross sections show strong dependence on beam energy and momentum transfer u ′. Λ polarization is compatible with zero. We compare energy dependence of the backward cross sections with the baryon exchange model from π N scattering.
No description provided.
No description provided.
No description provided.
We present the first data on photon-photon annihilation into hadrons for CM energies > 1 GeV obtained with the detector PLUTO at the e + e − storage ring PETRA. Cross sections are extracted using an inelastic eγ scattering formalism. The results are compared to expectations from Regge-like models.
DEPENDENCE OF CROSS SECTION FOR ELECTRON-PHOTON SCATTERING (ANALOGOUS TO HAND'S FORMULA) ON VISIBLE HADRONIC ENERGY, CALCULATED BY TAKING PION MASSES FOR ALL CHARGED PARTICLES.
We present new high statistics data on hadron production in photon-photon reactions. The data are analyzed in terms of an electron-photon scattering formalism. The dependence of the total cross section of Q 2 , the four-momentum transfer squared of the scattered electron, and on the mass W of the hadronic system is investigated. The data are compared to predictions from Vector-Meson Dominance and the quark model.
No description provided.
DEPENDENCE ON VISIBLE HADRONIC INVARIANT MASS.
Data read from graph.
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