We present results of complete measurements of the two-prong events observed in a 50 000-picture exposure of the 30-in. hydrogen bubble chamber to a 205−GeVc proton beam at the National Accelerator Laboratory. Using kinematic fitting, elastic and inelastic events are separated and cross sections are obtained. The total two-prong cross section is measured to be 9.77 ± 0.40 mb, of which 2.85 ± 0.26 mb represents the inelastic contribution. The total elastic cross section is measured to be 6.92 ± 0.44 mb. Our data are consistent with the break in dσdt at |t|∼0.1−0.2 (GeVc)2 observed at the CERN ISR. A prominent low-mass enhancement is observed in the distribution of missing mass squared from the slow proton for the inelastic events. An analysis based on the missing-mass spectrum and the particle rapidities shows that this low-mass enhancement accounts for about 77% of the total inelastic two-prong cross section. The diffractive cross section in the two-prong events is 2.20 ± 0.25 mb, in agreement with certain two-component models.
USING A TOTAL CROSS SECTION OF 39.0 +- 1.0 MB.
No description provided.
The magnitude of |f21(0)|, the coherent K0 regeneration amplitude in Cu, has been measured for K momenta from 600 to 1400 MeVc. Results are compared with predictions of an optical model using forward dispersion relation predictions for real parts of kaon-nucleon scattering amplitudes.
No description provided.
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.
A measurement of the complete differential cross section for the reaction pp→dπ+ at 3.00, 3.20, 3.43, 3.65, 3.83, 4.00, 4.20, and 5.05 GeVc incident proton momentum has been made in an attempt to establish the role of the Δ (1950) in this region. The data show that the previously observed enhancement in the forward cross section between 3 and 4 GeVc due to this isobar is an effect which damps out quickly as the production angle departs from zero degrees, in contrast with the well-known enhancement at 1.35 GeVc, which is evident at all angles. In particular, the one-pion-exchange model is in poor agreement with the extended set of data. A detailed description is given of a novel proportional-wire-chamber system which facilitated the selection of this rather rare reaction from a very high competing background.
Axis error includes +- 6/6 contribution.
Axis error includes +- 6/6 contribution.
No description provided.
We have observed a second sharp peak in the cross section for e+e−→hadrons at a center-of-mass energy of 3.695±0.004 GeV. The upper limit of the full width at half-maximum is 2.7 MeV.
No description provided.
Full angular distributions of the polarization parameter in elastic K+p scattering at 1.37, 1.45, 1.60, 1.71, 1.80, 1.89, 2.11, and 2.31 GeV/c are presented. These data were obtained in an experiment at the Zero Gradient Synchrotron using a polarized proton target with arrays of scintillation and Čerenkov counters to detect the scattered particles.
No description provided.
No description provided.
No description provided.
Results on multiplicities, topological cross sections, total particle production cross sections, and correlations between charged particle and π 0 production are presented for pp interactions at 12 and 24 GeV/ c incident laboratory momentum. Inclusive production of π ± , K s 0 , p , Λ, Σ ± and Λ is studied; particle spectra are shown in single and double differential form and are compared, in different kinematic regions, with data obtained at other incident momenta and with other beam particles.
No description provided.
No description provided.
We have measured the reaction cross section for p¯p→n¯n in small momentum steps between 0.97 and 3.13 Gev/c to a high level of statistical accuracy. Structures are observed in the vicinity of Plab=1.25 GeVc and 1.8 GeVc which are consistent with the structure observed in the p¯p total cross section.
No description provided.
Differential cross sections for π0 and ρ0 photoproduction from protons have been measured at photon energies 6, 12, and 18 GeV and momentum transfers 0.5 to 3 (GeVc)2.
No description provided.
No description provided.
No description provided.
We report measurements of the ratio of the deep-inelastic electron-neutron to electron-proton differential cross sections in the threshold ( ω <3) region. The ratio was found to scale and to decrease monotically with decreasing ω . No violation of the quark model lower bound of 0.25 was observed in the ratio.
DATA ARE AVERAGED THROUG AVAILABLE KINEMATIC REGION.
Forum