The production of N ∗ (1400) isobar in the reaction pp → pN ∗+ (1400), where N ∗ (1400) → n π + and p π 0 , is investigated with the aid of one-pion exchange model. The one-pion exchange mechanism does not seem to dominate the production process. The isospin of N ∗ (1400) is found to be I = 1 2 , and the elasticity of the resonance is estimated to be 0.66.
Axis error includes +- 0.0/0.0 contribution (?////Due to fitting mass spectrum).
Forward differential cross sections for isospin-1 bosons produced in p+p→d+x+ were measured using a deuteron missing-mass spectrometer at a small angle between 4.0- and 12.3−GeVc incident momentum. Differential cross sections for π+ and ρ+ were extracted from the spectra using phase-space backgrounds. They range from 10.4 to 0.4 μb/sr for π+ and from 1.4 to 0.3 μb/sr for ρ+. A bump near 6 GeVc appears in both dπ and dρ channels. No clear evidence is seen for higher-mass bosons. The possible δ+ cross sections average less than 0.01 μb/sr.
TECHNIQUE USED...ELECTRONIC. TABLE 1.
TECHNIQUE USED...MISSING MASS. BREIT WIGNER USED WITH FIXED WIDTH (150 MEV) AND VARIABLE MASS (LATTER VARIED WITH MOMENTA FROM 715 TO 765 MEV). 6 PERCENT NORMALIZATION ERROR; 20 PERCENT FROM BREIT WIGNER FIT. TABLE 1.
TECHNIQUE USED...MISSING MASS. CROSS-SECTIONS CORRESPOND TO VERY NARROW DELTA (962).
An experiment was done in the external proton beam of the Berkeley 184-in. cyclotron to measure the production cross sections for pions from various target nuclei, from hydrogen to lead. The cross-section data are presented and the reaction mechanisms discussed. The hydrogen production appears to fit the one-pion-exchange model.
No description provided.
The differential cross section of pp scattering has been measured in the energy region 100–300 GeV and in the t -range 0.002 < | t | < 0.04 (GeV/| c ) 2 . The results on the real part of the scattering amplitude agrees with dispersion relation calculations. We also report on our determination of the slope parameter b together with an analysis of the world data of b for different hadrons and different t -values. It is shown that the data are consistent with the hypothesis of a universal shrinkage of the hadronic diffraction cone at high energies.
FROM FITS TO D(SIG)/DT IN THE COULOMB-NUCLEAR INTERFERENCE REGION, USING TOTAL CROSS SECTION VALUES FROM A. S. CARROLL ET AL., PL 80B, 423 (1979). ERRORS INCLUDE STATISTICAL ERRORS AND ERRORS IN NORMALIZATION AND IN SIG.
Differential cross sections for π − p and pp elastic scattering have been measured at incident momenta ranging from 30 to 345 GeV and in the t range 0.002 (GeV/ c ) 2 ⩽ | t | ⩽ 0.04 (GeV/ c ) 2 . From the analysis of the data, the ratio ϱ ( t = 0) of the real to the imaginary parts of the forward scattering amplitude was determined together with the logarithmic slope b of the diffraction cone.
No description provided.
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We have obtained a sample of 20 465 (2201) events in the channel pp→ ( Λ 0 K + )p at 50 (30) GeV/ c incident momentum with Geneva-Lausanne spectrometer at the CERN SPS. In this analysis we investigate: 1. (i) the production of N ∗ (I = 1 2 ) states in the mass region 1.6 ⩽ M ( Λ 0 K + ) ⩽ 2.6 GeV and momentum transfer 0.06 ⩽ | t | 1.0 (GeV/ c ) 2 , by studing the amplitudes and phases from a moment analysis of the decay angular distribution; 2. (ii) the contribution of the K-exchange Deck model for M ( Λ 0 K + < 2.22 GeV; 3. (iii) the double Regge exchange phenomenology for s Λ 0 K + > 5 GeV 2 and s Λ 0 K + p > 5 GeV 2 .
No description provided.
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The inclusive cross sections for production of prompt photons and π0s by 280 GeV/c protons incident on a liquid hydrogen target, have been measured forpT in the range 4.0 to 6.5 GeV/c and for |xF|<0.45. A quantitative comparison of the prompt photon cross section with next-to-leading order QCD predictions using Duke and Owens structure functions is performed. Phenomenological fits to the π0 and prompt photon cross sections are given.
Invariant cross section.
No description provided.
Invariant cross section.
Accelerating polarized protons to 22 GeV/c at the Brookhaven Alternating Gradient Synchro- tron required both extensive hardware modifications and a difficult commissioning process. We had to overcome 45 strong depolarizing resonances to maintain polarization up to 22 GeV/c in this strong-focusing synchrotron. At 18.5 GeV/c we measured the analyzing power A and the spin-spin correlation parameter Ann in large- P⊥2 proton-proton elastic scattering, using the polarized proton beam and a polarized proton target. We also obtained a high-precision measurement of A at P⊥2=0.3 (GeV/c)2 at 13.3 GeV/c. At 18.5 GeV/c we found that Ann=(-2±16)% at P⊥2=4.7 (GeV/c)2, where it was about 60% near 12 GeV at the Argonne Zero Gradient Synchrotron. This sharp change suggests that spin-spin forces may have a strong and unexpected energy dependence at high P⊥2.
No description provided.
2.2 GeV point taken from Brown et al., PR D31(85) 3017.
No description provided.
The inclusive cross sections for η production by the interactions of 280 GeV/c momentum π−, π+, and proton beams in hydrogen have been measured. The kinematical range covered is −0.45<xF<0.45, and 4.0<PT<7.0 GeV/c for FeynmanxF and transverse momentum respectively. The η to π0 cross section ratios are given for the three reactions. The ratio of π−p to π+p cross sections for η production in the above kinematic ranges is 1.22±0.08±0.11.
No description provided.
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We have measured the asymmetry of elastic pp scattering at small scattering angles (30–100 mrad) in the Coulomb-nuclear interference region, using the polarized proton beam of Saturne II, a segmented scintillator active target, and two telescopes of multiwire proportional chambers. Results are given at four energies — 940, 1000, 1320 and 2440 MeV-and are compared with phase-shift calculations.
No description provided.
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