Elastic Σ − p and π − p cross section have been measured at 17.2 GeV/ c in the t interval −0.12, −0.38 (GeV/ c ) 2 . The Σ − p slope is b = 8.12 ± 0.35 (GeV/ c ) −2 .
No description provided.
NORMALIZED TO PI- P ELASTIC FORWARD DIFFERENTIAL CROSS SECTION OF 31.2 +- 1.9 MB/GEV**2 (PLUS 6 PCT SYSTEMATIC ERROR) OF K. J. FOLEY ET AL., PRL 11, 425 (1963).
NUMERICAL VALUES SUPPLIED BY J. J. BLAISING AND ADDED TO RECORD ON 19 DEC 77.
The single diffraction dissociation process pp → (p π + π − )p has been studied at the CERN ISR at √ s = 45 GeV and 0.1 < − t < 0.6 GeV 2 . The reaction is dominated by nucleon resonance production: pp → pN (1520) and pp → pN(1688) with cross-sections (0.25 ± 0.08) mb and (0.56 ± 0.19) mb respectively.
DIFFERENTIAL CROSS SECTIONS FOR THREE RANGES OF <P PI+ PI-> MASS.
FROM BREIT-WIGNER PLUS BACKGROUND FITS. CORRECTIONS FOR OTHER DECAY MODES USE THE PDG 1974 TABLES FOR N(1520) AND N(1688).
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K + p elastic scattering is studied at incident K + beam momenta of 2.53, 2.76 and 3.20 GeV/ c . From the analysis of about 10 000 elastic events at each energy, we present data on the forward and backward elastic scattering peaks. No structure is observed in the forward peak for − t ⩽ 2 (GeV/ c ) 2 . In addition, the statistics available from this exposure permit a measurement of the differential cross sections near 90° in the center of mass system. These results exhibit a strong energy dependence and are compared to similar results at other energies.
No description provided.
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THE QUOTED ERRORS ARE STATISTICAL.
Cross sections, differential cross sections, and hyperon polarization results are presented for the reactions K¯0p→Λπ+ and K¯0p→Σ0π+ in the momentum interval 1 to 12 GeV/c. Emphasis is placed on the comparison of Λ and Σ channels, and on the momentum dependences of the data. In particular, the Λ polarization data are consistent with being independent of energy above 2 GeV/c; and the slopes of the forward cross sections are found to increase toward the slope values for the line-reversed reactions πp→K(Λ,Σ) as energy increases.
No description provided.
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RESONANCE REGION CROSS SECTIONS.
Cross sections, differential cross sections, density matrix elements and statistical tensors are given for the reactions π + p → ( ϱ 0 , ω ) Δ ++ at 13.2 GeV/ c . A discussion of the results in terms of particle exchanges, quark model or dipole coupling constraints, and the equal phase hypothesis is presented in some detail for the high statistics ϱ 0 Δ ++ channel.
BREIT-WIGNER FITS WHICH CORRECT FOR RESONANCE TAILS AND BACKGROUNDS.
No description provided.
JACKSON FRAME DENSITY MATRIX ELEMENTS.
A systematic analysis is presented on the reaction K + p → K ∗0 (890) Δ ++ for nine incident momenta between 4.6–16.0 GeV/ c . Cross sections, differential cross sections and vector meson single density matrix elements are given. As a function of energy, little if any change is observed in either the shapes of the differential cross sections or in the values of the density matrix elements. The data are interpreted in terms of current ideas on t -channel exchange mechanisms.
No description provided.
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Results are presented on the elastic scattering of photons by protons. The incident photon energy ranged from 0.55 GeV to 4.5 GeV, and the four-momentum transfer t ranged from 0.12 to 1.0 (GeV/c)2. The data at large angles, 60°<θ*<115°, are characterized by a pronounced excitation of the D13(1518) resonance, a shoulder in the 1688-MeV mass region, and a precipitous drop thereafter in the cross section as a function of incident energy. The low-t data are characterized by a diffraction slope of 5 (GeV/c)−2. The data are inconsistent with the predictions of the vector-dominance model if the latter is restricted to ρ0, ω, and φ vector mesons.
No description provided.
At the Bonn 2.5 GeV synchrotron the differential photoproduction cross section d σ /d t of φ mesons has been measured at a photon energy of 2.0 GeV at fibe different t values between 0.23 < | t | < 0.73 (GeV/ c ) 2 . The φ meson was detected by magnetic momentum analysis of both charged decay K mesons and by a time of flight and angle measurement of the coincident recoil proton. We found an exponential behaviour for the t dependence of the cross section. The measured slope of the exponential decrease was b = (4.01 ± 0.23) (GeV/ c −2 . This result, combined with previous measurements at higher energies, implies that the slope of the pomeron trajectory is compatible with zero. In addition the experiment yielded a value of the φ mass, m φ = (1019.4 ± 0.8) MeV and a value of the φ width, Γ = (4.4 ± 0.4) MeV.
No description provided.
The reaction γ d→d ππ , γ p→p ππ and γ n→n ππ were studied in the SLAC 82″ deuterium filled bubble chamber, exposed to a linearly polarized photon beam of 7.5 GeV. All three reactions are dominated by ϱ 0 production. The differential cross section has a slope of ∼6.5 GeV −2 for nucleon reactions and a slope of ∼27 GeV −2 for coherent deuteron reactions. The behaviour of the density matrix elements shows that ϱ production conserves s -channel c.m.s. helicity and is dominated by natural parity exchange.
No description provided.
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