We have measured the production polarization and magnetic moment of a sample of 89×103Ξ− hyperons produced in the inclusive reaction p(400 GeV/c)+Cu→Ξ−+X. The weighted average of the polarization is -0.070±0.008±0.010 at a pt of 0.63 GeV/c. The Ξ−'s magnetic moment yields the value μΞ=−0.661±0.036±0.036 nuclear magnetons. The first error is statistical, the second systematic.
No description provided.
In order to improve existing I=0 phase shift solutions, the spin correlation parameter ANN and the analyzing powers A0N and AN0 have been measured in n-p elastic scattering over an angular range of 50°–150° (c.m.) at three neutron energies (220, 325, and 425 MeV) to an absolute accuracy of ±0.03. The data have a profound effect on various phase parameters, particularly the P11, D23, and ε1 phase parameters which in some cases change by almost a degree. With the exception of the highest energy, the data support the predictions of the latest version of the Bonn potential. Also, the analyzing power data (A0N and AN0) measured at 477 MeV in a different experiment over a limited angular range [60°–80° (c.m.)] are reported here.
The beam analysing power at incident kinetic energy 220 MeV. Additional systematic uncertainty of +- 0.015 and a scalar error of 3.5 PCT.
The beam analysing power at incident kinetic energy 325 MeV. Additional systematic uncertainty of +- 0.018 and a scalar error of 3.1 PCT.
The beam analysing power at incident kinetic energy 425 MeV. Additional systematic uncertainty of +- 0.022 and a scalar error of 3.3 PCT.
None
No description provided.
No description provided.
No description provided.
The excitation function of the reaction p p→ Λ Λ in the threshold region has been measured at LEAR. Sixteen measurements of the total cross section, in the energy range between 0.85 MeV below threshold and 4.05 MeV above, are presented. The shapes of the measured differential cross sections indicate a remarkably strong p-wave contribution even down to the reaction threshold. We also report here the measurement of significant polarizations in the threshold region; these are compared with previous higher-energy data.
Data to be supplied by authors.
No description provided.
No description provided.
The spin asymmetry in deep inelastic scattering of longitudinally polarised muons by longitudinally polarised protons has been measured in the range 0.01<×<0.7. The spin dependent structure function g 1 ( x ) for the proton has been determined and, combining the data with earlier SLAC measurements, its integral over x found to be 0.126±0.010(stat.)±0.015(syst.), in disagreement with the Ellis-Jaffe sum rule. Assuming the validity of the Biorken sum rule, this result implies a significant negative value for the integral of g 1 for the neutron. These integrals lead to the conclusion, in the naïve quark parton model, that the total quark spin constitutes a rather small fraction of the spin of the nucleon. Results are also presented on the asymmetries in inclusive hadron production which are consistent with the above picture.
THE MEAN Q**2 FOR EACH OF THE 10 VALUES OF X BELOW ARE 3.5,4.5,6.0, 8.010.3,12.9,15.2,18.0,22.5,29.5.
No description provided.
No description provided.
The mixed spin-spin correlation parameter Cσσ≈0.5CSS−0.8CSL for np elastic scattering was measured for incident-neutron-beam kinetic energies of 484, 634, and 788 MeV over the center-of-mass angular range 75°-180°. These Cσσ data are important for determining the I=0 nucleon-nucleon amplitudes and provide strong constraints on the phase-shift solutions. It was found that the P11, S13, and D13 isospin-0 partial waves are most strongly affected.
Mixed spin parameter POL.POL(NAME=CXX) is given by 0.475 * CSS + 0.088 CNN + 0.1390 CLL - 0.744 CSL.
Mixed spin parameter POL.POL(NAME=CXX) is given by 0.506 * CSS + 0.064 CNN + 0.163 CLL - 0.809 CSL.
Mixed spin parameter POL.POL(NAME=CXX) is given by 0.528 * CSS + 0.050 CNN + 0.178 CLL - 0.824 CSL.
The spin-correlation parameter Ann for free n-p elastic scattering has been measured for the first time for incident-neutron-beam energy En=790 MeV and c.m. angles 48°≤θ*≤149°. The data are compared with the widely differing predictions of several phase-shift analyses, clearly favoring one of them. They also are compared with recently published quasifree Ann data for the more limited c.m. angular region 98°≲θ*≲122°.
No description provided.
The polarization parameter Pn000, the two-spin parameters Dn0n0, Kn00n, Ds′0s0, Ds′0k0 and the three-spin parameters Ms′0sn and Ms′0kn have been measured for pp elastic scattering angles between 60° and 88° center of mass at 241 and 314 MeV incident kinetic energies, and between 38° c.m. and 98° c.m. at 341, 366, and 398 MeV. At 473 MeV, only Pn000 and Ds′0k0 were measured between 34° c.m. and 62° c.m. The experiment was performed at SIN using a polarized proton beam and a polarized butanol target. The polarization of the scattered proton was analyzed in a carbon polarimeter. The influence of these high-precision data on the Saclay-Geneva phase-shift analysis is discussed.
Statistical errors only.
Statistical errors only.
Statistical errors only.
A study of the inclusive polarization of Λ hyperons produced by 400-GeV/c protons incident on nuclear targets has been performed at Fermilab. The polarization P of the Λ has been mapped over a large range of xF and pT to good precision for pT up to 3.8 GeV/c. The magnitude of the polarization at fixed xF rises with pT to a plateau at about 1 GeV/c, and the size of the plateau increases monotonically with xF. The Λ¯ were found to be unpolarized for pT<2.4 GeV/c. A target-nucleus dependence for the Λ polarization has been observed.
No description provided.
No description provided.
No description provided.
The polarization of the recoil proton in π+p and π−p elastic scattering using a liquid-hydrogen target has been measured for backward angles at 547 and 625 MeV/c. The scattered pion and recoil proton were detected in coincidence using the large-acceptance spectrometer to detect and analyze the momentum of the pions and the JANUS polarimeter to identify and measure the polarization of the protons. Results from this experiment agree with other measurements of the recoil polarization, with analyzing-power data previously taken by this group, and with predictions of partial-wave analyses.
No description provided.
No description provided.
No description provided.
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