Elastic scattering of p¯ on p has been studied for cosθc.m. between -0.88 and -1.0 and Plab(p¯) between 0.70 and 2.16 GeV/c. The momentum dependence of the cross section shows a sharp dip at 0.9 GeV/c and a broad peaking around 1.4 GeV/c. The possibility of the peak resulting from direct formation of boson resonances has been studied. Alternatively, a diffraction model agrees qualitatively with our data and other elastic data at different angles.
'1'. '2'. '3'.
No description provided.
No description provided.
The cross section for 180° elastic scattering of antiprotons by protons between 406 and 922 MeV/c has been measured. A single-arm spectrometer detected recoil protons corresponding to events with 〈cosθc.m.〉=−0.994. The regions of the reported resonances at 1936 and 2020 MeV were scanned in 10-MeV/c steps with a typical statistical error of ≈ 7% and an rms mass resolution of ±3 MeV. No narrow enhancements (Γ<10 MeV) were observed.
735 MEV/C VALUE MISPRINTED IN JOURNAL - CORRECTION SUPPLIED BY M. A. GARNJOST (PRIV COMM 28 MAR 1980).
The differential cross section for the charge-exchange reaction K−p→K¯0n has been measured at 22 incident momenta between 515 and 956 MeV/c. Experimental results and Legendre-polynomial fits to the data are presented.
No description provided.
No description provided.
No description provided.
In this paper we report measurements of the backward K−p differential cross section at 49 momenta covering the momentum range 476-1084 MeV/c. The statistical precision achieved, typically 2.5%, is an order of magnitude better than previous measurements. The systematic errors for this reaction are about 1%. The differential cross section for the reaction K−p→Σ−π+ where the π+ emerges at 0° has also been measured at 32 momenta with comparable improvement in precision over previous experiments. A partial-wave analysis of the K¯N channels including the new K−p backward elastic data is presented.
No description provided.
No description provided.
We have studied the process p¯p into π+X− using wire spark chambers. The data cover the angular range of cosθp¯π+* between 0.96 and 1.0 at several incident momenta between 1 and 2 GeVc. The reaction p¯p→π+ρ− was observed with (dσdΩ)* of the order of 100 μb/sr at several momenta.
READ FROM GRAPH.
Total and differential cross sections for the reaction gamma p -> pi^o eta p have been measured with the Crystal Ball/TAPS detector using the tagged photon facility at the MAMI C accelerator in Mainz. In the energy range E_gamma=0.95-1.4 GeV the reaction is dominated by the excitation and sequential decay of the Delta(1700)D33 resonance. Angular distributions measured with high statistics allow us to determine the ratio of hadronic decay widths \Gamma_{\eta \Delta}/\Gamma_{\pi S11} and the ratio of the helicity amplitudes A_{3/2}/A_{1/2} for this resonance.
Total cross section for the GAMMA P --> PI0 ETA P reaction.. Statistical erros only.
The differential cross section as a function of cos(theta(pi0) in the canonical(K) reference frame.. Statistical erros only.
The differential cross section as a function of phi(pi0) in the canonical(K) reference frame.. Statistical erros only.
Pions from the reaction γ + p → π + + n were analysed in the backward direction by a magnetic spectrometer. The photon energy region of 0.394 GeV to 1.397 GeV was covered by 19 different momentum settings. Data reduction resulted in 74 measured differential cross sections with statistical uncertainties typically from 4% to 8%. The systematic uncertainty was estimated to be ±5%. The data are compared to other recent experiments and predictions of phenomenological analyses.
No description provided.
Excitation functions of proton-proton elastic scattering cross sections have been measured in narrow steps for projectile momenta pp (energies Tp) from 1100 to 3300MeV/c (500 to 2500 MeV) in the angular range 35°≤Θc.m.≤90° with a detector providing ΔΘc.m.≈1.4° resolution. Measurements have been performed continuously during projectile acceleration in the cooler synchrotron COSY with an internal CH2 fiber target, taking particular care to monitor luminosity as a function of Tp. The advantages of this experimental technique are demonstrated, and the excitation functions obtained are compared to existing cross section data. No evidence for narrow structures was found.
No description provided.
No description provided.
No description provided.
The cross section of the pure QED process e + e − → γγ has been measured using data accumulated during the 1989 and 1990 scans of the Z 0 resonance at LEP. Both the energy dependence and the angular distribution are in good agreement with the QED prediction. Upper limits on the branching ratios of Z 0 → γγ , Z 0 → π 0 γ and Z 0 → ηγ have been set at 1.4×10 −4 , 1.4×10 −4 and 2.0×10 −4 respectively. Lower limits on the cutoff parameters of the modified electron propagator have been found to be Λ + > 117 GeV and Λ − > 110 GeV. The reaction e + e − → γγγ has also been studied and was found to be consistent with the QED prediction. An upper limit on the branching ratio of Z 0 → γγγ has been set at 6.6 × 10 −5 . All the limits are given at 95% confidence level.
No description provided.
No description provided.
No description provided.
The reaction γp → K 0 Σ + has been measured with the SAPHIR detector at the electron stretcher ring ELSA. The total cross section rises up to a peak value of 1.1 μ b at a photon energy of 1.4 GeV. The differential cross sections dσ/dΩ are consistent with being flat throughout the measured energy range. The first measurement of the Σ + polarization in photon induced reactions was obtained.
Total cross section for the reaction GAMMA P --> K0 SIGMA+. Errors include statistics and the uncertainty on the acceptance calculation and photon flux.
Differential cross section for the reaction GAMMA P --> K0 SIGMA+. Errors are dominated by statistical uncertainties.
Measure of SIGMA+ polarization in the reaction GAMMA P --> K0 SIGMA+.
Forum