S. Jaccard

Energy dependence of the pp→π+d differential cross section between 500 and 600 MeV

Abstract The unpolarized differential cross section for the reaction pp→π + d has been measured at SIN at seven energies between 514 and 583 MeV. Data are presented in terms of a Legendre polynomial expansion. An observed strong energy dependence of the 4th order coefficient can be understood as a threshold phenomenon in a phenomenological NΔ resonant description. No evidence was found for a 1 D 2 dibaryon resonance near 600 MeV.

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 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.

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.

The analysing power of the reaction pp → πd for proton energies between 500 AND 600 MeV

Abstract The analysing power A y0 of the pp → π d reaction has been measured at SIN for four energies between 516 and 582 MeV with a statistical precision of better than 1%. Pions and deuterons have been detected in coincidence with scintillation detectors employing time-of-flight techniques for event identification. Using our data on the differential cross section σ, Legendre polynomial expansion coefficients b j y0 for the product σA y0 have been deduced for j = 1 to 5. The energy dependence of these coefficients has been compared with theoretical 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°.

Measurement of the analyzing power in the pp→π+d reaction

The analyzing power, Ayo, of the reaction pp→π+d has been measured to an accuracy of about 1% at 4 energies between 500 and 600 MeV at S.I.N. Pions and deuterons were detected in coincidence with scintillation detectors, using TOF techniques for event identification. Asymmetry results show considerable energy dependence in magnitude and shape. Final results have been fit, together with precise differential cross section data which were corrected for multiple scattering, pion decay, and muon detection. Numerical values of Legendre polynomial coefficients to describe Ayo and the differential cross section will be presented.