Measurements of the photoproduction from hydrogen of single K + mesons at gamma ray energies of 3.4 and 5.0 GeV and at laboratory angles of 5.1°, 7.1°, 9.9° and 15.1° are reported. The s dependence at fixed t is derived for momentum transfers of −0.25 and −0.37 (GeV) 2 .
Axis error includes +- 13/13 contribution (Ovearall systematic uncertainty. Included).
Axis error includes +- 13/13 contribution (Ovearall systematic uncertainty. Included).
We have studied the reaction e−+p→e−+π++n by detecting the final electron and pion in coincidence. Data are presented in the region of virtual photon mass squared from -0.18 to -1.2 GeV2, and virtual photoproduction center-of-mass energy and angle from 1.85 to 2.50 GeV and 0 to 20°, respectively.
No description provided.
No description provided.
No description provided.
We report measurements of the photoproduction from hydrogen of single π+ mesons at gamma-ray energies of 3.4 and 5.0 BeV and at laboratory angles of 5.1°, 7.1°, 9.9°, and 15.1°. The s dependence at fixed t is derived for momentum transfers of -0.20, -0.37, and -0.70 BeV2. The pion data are compared with a Reggeized one-pion-exchange model.
No description provided.
Results are presented on the inclusive photoproduction of λ and λ for incident photon energies between 25 and 70 GeV. The slope parameter of the p T 2 distribution is found to be 2.83±0.1 GeV −2 for λ and 3.28±0.25 GeV −2 for λ . The x F distributions, measured in the range −0.2 to 0.7, show that while λ are produced centrally, λ production extends to more negative values of x F ; the shapes show no energy dependence and are similar to those in pion-induced reactions. The polarization of the produced λ is less than 10%. The results are discussed in terms of vector dominance and quark fusion models.
No description provided.
No description provided.
No description provided.
The angular distribution of proton-proton elastic scattering has been measured for incident beam momenta of 10.0, 12.0, 14.2 and 24.0 GeV/ c over a range of laboratory scattering angles from 12 to about 140 mrad. The results are compared with the fourth power of the electromagnetic form of the proton.
No description provided.
Measurements of the reaction γ p → p π + π − π + π − are presented, in which π + π − π + π − systems with masses up to 3 GeV are produced from fragmentation of the incident photon. The reaction is dominated by production of the large peak of the ϱ′(1600) meson and, at higher masses ≳2 GeV, y production of jet-like 4 π systems. The ϱ′(1600) meson is produced by a predominantly s -channel helicity conserving mechanism. At higher masses there are also indications of ϱπ peaks, of masses 1.3 GeV (the A 2 meson) and 1.75 GeV, produced with a recoiling π meson by a mechanism consistent with the Deck effect.
CORRECTED FOR TAILS OF BREIT-WIGNER RESONANCE USED IN FIT AND ALLOWING FOR 10 PCT BACKGROUND.
The reaction γ p→K + K − p has been investigated with photons in the energy range of 20< E γ <36 GeV and with K + K − pairs in the mass range of M K + K − <2.0 GeV. The production of the φ(1019) contributes with a cross section σ ( γ p → φ p) × BR( φ →K + K − ) = 240±6 nb with an additional systematic error of ±20 nb. In the higher mass range of 1.05< M K + K − <2.0 GeV the production of K + K − pairs yields a cross section σ ( γ p→K + K − p) = 160±8 nb with an additional systematic error of +40 −30 nb.
No description provided.
K+ K- PRODUCTION ABOVE PHI MASS.
No description provided.
A dipion enhancement of mass 1.59 GeV and width 0.23 GeV is observed in the channel γp→π + π − p. The spin-parity of the enhancement is consistent with being 1 − .
No description provided.
Angular distributions of proton-proton elastic scattering have been measured for incident beam momenta of 10.0, 12.0, 14.2 and 24.0 GeV/ c over a range of lab scattering angles from 12 to 152 mrad. This is equivalent to a range of four-momentum transfer squared from about 0.1 to 6.7 GeV 2 at the highest momentum. Nucleon resonance production in the two-body reaction p + p → p + X has been studied at 24.0 GeV/ c incident momentum from 13.5 to 112 mrad by measuring the proton momentum spectra from the elastic peak down to a momentum corresponding to a missing mass of about 2.6 GeV. The new data are compared with previous results and theoretical models.
ESTIMATED 8 PCT RANDOM ERROR.
ESTIMATED 8 PCT RANDOM ERROR.
ESTIMATED 8 PCT RANDOM ERROR.
Measurements of proton-deuteron scattering have been performed using an incident 24.0 GeV/ c proton beam. Momentum-loss spectra of forward-scattered protons were measured by a single-arm spectrometer over a range of proton angles from 13 to 107 mr. The contributions to the proton spectra of single and double scattering can be separated experimentally, thus allowing estimates of proton-neutron elastic cross sections to be deduced from the data over a range of four-momentum transfer squared, |t| 5.8 GeV 2 . Elastic p - d scattering, in which the proton and deuteron were detected in coincidence, has also been measured over a range of | t | from 0.6 to 1.8 GeV 2 .
No description provided.
EXTRACTED FROM SINGLE AND DOUBLE PEAK DEUTERIUM DATA BY THE GLAUBER METHOD WITH FERMI MOTION CORRECTIONS.
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