We measured d σ d t(90° cm ) for ↑+ p ↑→ p + p from 1.75 to 5.5 GeV/ c , using the Argonne zero-gradient synchrotron 70% polarized proton beam and a 70% polarized proton target. We found that the spin-spin correlation parameter. A nn , equals 60% at low energy, then drops sharply to about 10% near 3.5 GeV/ c , and remains constant up to 5.5 GeV/ c .
ANALYZING POWER. QUOTED ERRORS DUE TO 4.3 PCT POINT TO POINT RELATIVE ERROR.
THE SPIN-SPIN CORRELATION PARAMETER CNN IS NOW DENOTED BY ANN ACCORDING TO THE NEW ANN ARBOR CONVENTION.
We measured dσdt for p+p→p+p at 11.75 GeV/c using the zero-gradient synchrotron 70% polarized-proton beam and a 65% polarized-proton target. We obtained the spin-orbit asymmetry parameter A and the spin-spin correlation parameter Cm out to P⊥2=4.2 (GeV/c)2. We found that A drops smoothly towards zero, but that Cnn increases abruptly near P⊥2=3.6 (GeV/c)2, where the exp(−1.4P⊥2) component of elastic scattering becomes dominant. This suggests that large-P⊥2 "hard" elastic scattering may occur mostly when the two proton spins are parallel.
No description provided.
We have measured the spin-spin correlation parameter CNN at 2, 3, 4, and 6 GeV/c over the |t| range of 0.1 to 2.0 (GeV/c)2 and have observed a striking energy and |t| dependence in CNN. Polarization data were simultaneously collected and are compared to previous results.
CNN PARAMETER MEASURED.
We measured the differential cross section for proton-proton elastic scattering at 6 GeV/c, with both initial spins oriented normal to the scattering plane. The analyzing power A shows significant structure with a large broad peak reaching about 24% near P⊥2=1.6 (GeV/c)2. The spin-spin correlation parameter Ann exhibits more dramatic structure, with a small but very sharp peak rising rapidly to about 13% at 90°c.m.. This sharp peak may be caused by particle-identity effects.
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The energy dependence of the spin-parallel and spin-antiparallel cross sections for p↑+p↑→p+p at 90°c.m. was measured for beam momenta between 6 and 12.75 GeV/c. The ratio (dσdt)parallel:(dσdt)antiparallel at 90° is about 1.2 up to 8 GeV/c and then increases rapidly to a value of almost 4 near 11 GeV/c. Our data indicate that this ratio may depend only on the variable P⊥2, and suggests that the ratio may reach a limiting value of about 4 for large P⊥2.
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The Wolfenstein parameters D, R, and A and the polarization parameter P have been measured for p−p elastic scattering at 312, 392, 493, and 575 MeV kinetic energy. The center-of-mass angular range observed was from 3° to 33°. The experiment was performed at SIN, using a polarized proton beam. These data significantly improve the determination of I=1 phase shifts.
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We measured the cross section for proton-proton elastic scattering at 11.75 GeV/c using the Zero Gradient Synchrotron 52% polarized proton beam and a 60% polarized proton target. We measured dσdt(ij) in the ↑↑, ↓↓, and ↑↓ initial spin states perpendicular to the scattering plane in the range P⊥2=2.0−3.6 (GeV/c)2. We found that the asymmetry parameter A decreases smoothly with increasing P⊥2 in this range, and that the spin-spin correlation parameter Cnn may have a minimum near P⊥2=3 (GeV/c)2.
No description provided.
Using the polarized-beam facility at Argonne National Laboratory and a polarized proton target, simultaneous measurements of the spin parameter P and the spin correlation term CNN were made. Data were obtained and analyzed at beam momenta of 2, 3, 4, and 6 GeV/c in the momentum-transfer-squared interval 0.1≤|t|≤2.8 (GeV/c)2. A preliminary phase-shift analysis of the 2- and 3-GeV/c data is discussed and a comparison with predictions of a particular Regge-pole model at all four energies is made.
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A polarized proton beam extracted from SATURNE II, the Saclay polarized target with$^6$Li compounds, and
Analysing power measurements in the scattering of polarized protons from either hydrogen in the LiH target or on bound protons in the LiD target. The three sets of results are independent.
Analysing power measurements in the scattering of polarized protons from either hydrogen in the LiH target or on bound protons in the LiD target. The three sets of results are independent.
Analysing power measurements in the scattering of polarized protons from either hydrogen in the LiH target or on bound protons in the LiD target. The three sets of results are independent.
We measured dσdt for p↑+p↑→p+p from P⊥2=4.50 to 5.09 (GeV/c)2 at 11.75 GeV/c. We used a 59%-polarized proton beam and a 71%-polarized proton target with both spins oriented perpendicular to the scattering plane. In these large-P⊥2 hard-scattering events, spin effects are very large and the ratio (dσdt)↑↑:(dσdt)↑↓ grows rapidly with increasing P⊥2, reaching a value of 4 at 90° (c.m.). Thus, hard elastic scattering, which is presumably due to the direct scattering of the protons' constituents, may only occur when the two incident protons' spins are parallel.
THE ERRORS INCLUDE STATISTICAL AND SYSTEMATIC ERRORS ADDED IN QUADRATURE. THE PARALLEL/ANTIPARALLEL SPIN CROSS SECTION RATIO IS (1+CNN)/(1-CNN).
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