Search

The aim of the deuteron spin structure (DSS) experiment is to obtain polarization observables in dp elastic scattering and in dp breakup at large CMS angles (> 60°). The dp breakup reaction has been investigated by the scintillation detectors placed at the vicinity of the Internal Target Station (ITS) of Nuclotron. Calibration data have been obtained at the deuteron energy of 300 - 500 MeV. The main goal of this report is to present the calibration procedure of the ΔE - E detectors. Calibration coefficients are used to recover the deposited particle energy.

The paper presents measurements of the noise characteristics of silicon photomultipliers in the temperature range from 27.7 °C to 39.1 °C, as well as study of the response of the detector prototypes with Ketek and Hamamatsu SiPM readout to the light source at different voltages. The prototype with SiPM readout from Ketek was tested at the Joint Institute for Nuclear Research Nuclotron deuteron beam at the energy of 4 GeV/nucleon. Time resolution and amplitude of the signal have been estimated.

Analyzing power in elastic proton-proton scattering was obtained at the Nuclotron Internal Target Station using a polarized deuteron beam and a polyethylene target. The selection of useful events was performed using the time and amplitude information from scintillation counters. The asymmetry on hydrogen was obtained by the subtraction of the carbon background. The obtained analyzing power values are compared with the predictions of the partial-wave analysis SAID at the beam energies of 500 and 650 MeV/nucleon.

The vector Ay and tensor analyzing powers Ayy and Axx for dp-elastic scattering were measured at the energy of 800 MeV and at the angular range from 60° to 135° in the center-of-mass system at the JINR Nuclotron. The experimental data are compared with the calculations obtained within framework of relativistic multiple scattering approach.