Excitation functions of spin correlation parametersANN,ASS, andA

Abstract

Excitation functions of the spin correlation coefficients ANN (p lab , θc.m.), ASS(p lab , θc.m.), and ASL(p lab , θc.m.) have been measured with the polarized proton beam of the Cooler Synchrotron COSY and an internal polarized atomic beam target. Data were taken continuously during the acceleration for proton momenta p lab ranging from 1000 to 3300 MeV/c (kinetic energies T lab 450 -2500 MeV) as well as for discrete momenta of 1430 MeV/c and above 1950 MeV/c covering angles θc.m. between 30• and 90• . The data are of high internal consistency. Whereas ASL(p lab, θc.m.) is small and without structures in the whole range, ANN and even more ASS show a pronounced energy dependence. The angular distributions for ASS are at variance with predictions of existing phase shift analyses at energies beyond 800 MeV. The impact of our results on phase shift solutions is discussed. The direct reconstruction of the scattering amplitudes from all available pp elastic scattering data considerably reduces the ambiguities of solutions.

Deuteron and proton beams polarimetry at internal target at JINR Nuclotron.

“…For this purpose the measurements of the proton beam polarization using several pairs of the detectors placed in the kinematic coincidences corresponding to ppelastic scattering in the horizontal plane (orbit plane of Nuclotron) have been proposed. The similar method has been used at COSY using EDDA setup [21,22]. The feasibility of the proposed method at ITS has been checked in November 2016 run at Nuclotron using polarized deuteron beam with the energy of 500 MeV/nucleon.…”