W.R. Leo

Measurement of the total cross section difference ΔσT(pp) in the energy range from 0.43 to 2.4 GeV

Abstract The SATURNE II polarized proton beam and the Saclay frozen spin polarized proton target were used to measure the total cross section difference Δσ T = −2 σ 1 tot at 26 energies between 0.43 and 2.4 GeV. Here Δσ T is the total cross section difference for transverse beam and target spins parallel and antiparallel, respectively, and σ 1tot is one of spin-dependent terms in the total cross section σ tot . The energy dependence of Δσ T below 1 GeV shows similar structures as for Δσ L . An additional minimum appears at about 1.3 GeV, which involves a structure in singlet spin partial waves.

p(↑)+p(↑) → π+d at 515 and 578 MeV

Abstract The polarization asymmetries A 0 y and A y 0 , and the spin correlation parameter A yy have been measured at SIN at 515 and 578 MeV using a transversally polarized proton beam and target. The results are compared with various theoretical models.

Measurement of ΔσL in pp scattering between 200 and 583 MeV

Abstract The main structure around m = 2.15 GeV first observed by the Argonne group in the spin-dependent total cross section Δσ L is confirmed in the energy range available at SIN. A simultaneous study of the scattered particles at small angles has been carried out with success and gave the spin-correlation parameter A 00 kk for the pp elastic scattering and for the reaction pp → π + d. The contribution of the 3-body reactions to this spin-dependent total cross section has been deduced and found to be lower than the contribution of the π + d reaction even at 583 MeV.

Measurement of the spin correlation parameter A00nn and the polarization A00n0 in elastic p-p scattering between 400 and 600 MeV

Abstract We have measured the spin correlation parameter A 00 nn and the polarization A 00 n 0 for p-p elastic scattering in the c.m. angular range between 30° and 90° at seven energies between 400 and 600 MeV. The experiment was performed at SIN using a polarized beam and target and a fast on-line event reconstruction method. The results are compared with phase-shift predictions.

Study of the reaction pp → π+d with a polarized beam and target☆

Abstract We have measured at the SIN-ring cyclotron the spin dependent parameters A yo A oy , A yy , A xx , A zz and A zx for the pp → π + d reaction, at 578 and 515 MeV. The 578 MeV data are presented.

Spin correlations and analyzing powers in pp → π+d between 447 and 578 MeV

Abstract The analyzing power A n 0( θ ) and the spin correlation parameters A nn ( θ ), A ss ( θ ), A kk ( θ ), A sk ( θ ) have been measured in the reaction pp → π + d over a large angular range at 447, 496, 515, 538 and 578 MeV. The experiments were performed at SIN, using a polarized proton beam and a polarized proton target. The measured angular distributions have been fitted to phenomenological partial wave expansions in terms of Legendre polynomials and associated functions. Results have been compared with several calculations based on different theoretical models. At the lower energies, the agreement is reasonably good; however, none of the theories is able to explain all the results in a satisfactory way.

Measurement of the spin correlation parameters Aoosk and Aookk in pp elastic scattering at 0.84 and 1.0 GeV

The spin correlation parameters Aoosk and Aookk were measured at 0.834 and 0.995 GeV using the SATURNE II polarized proton beam and the Saclay frozen spin polarized target. The measurements were carried out in the angular region φCM from 50° to ≃ 90°. The shape of the angular distribution Aoosk (pp) = f(θCM) changes rapidly from 0.8 to 1.0 GeV. The Aookk data points specify our previous measurements.

A direct reconstruction of the scattering amplitudes for the reaction pp → πd at 90° and 0° c.m. between 447 and 578 MeV

Abstract A reconstruction of the scattering amplitudes for pp → π d at 90° and 0° c.m. is made from five sets of five polarization parameters measured at 447, 496, 515, 538, 578 MeV. These data allow a determination of the moduli and one relative phase of the three amplitudes at 90° angle and two of the moduli at 0°. The deuteron tensor polarizations are also computed from these two reconstructions.

Measurements of the spin-correlation parametersA00kk,A00ks, andA00ssinp−pelastic scattering between 400 and 600 MeV

We have measured the spin-correlation parameters A/sub 00k/k, A/sub 00k/s, and A/sub 00s/s in p-p scattering between 400 and 600 MeV using a longitudinally polarized beam and a butanol target polarized in the horizontal plane. Owing to the restrictive geometrical acceptance of the target, the polarization axis of the target was oriented at an angle ..cap alpha.. with respect to beam direction. The parameters A/sub 00k/k and A/sub 00k/s were therefore measured as a linear combination at 577, 536, 514, 494, and 445 MeV. These experiments were extended to the measurement of A/sub 00k/s and A/sub 00s/s by using a transversely polarized beam. We present the results, which are compared with phase-shift predictions.

Measurements of the polarization A and the spin‐correlation Ann

The experiment was performed at SIN using a polarized proton beam with ‖p↘B‖= (41.65±0.43) % and a polarized butanol target. Beam polarization was produced by scattering the main 590 MeV unpolarized beam from a thin Be target and selecting the elastically scattered portion at 8°.