Newly developing SPASCHARM (SPin Asymmetry in CHARMonia) experiment at U70 accelerator will give the unique possibility to measure spin effects with the use of polarized proton and antiproton beams and polarized target. We suggest to carry out the measurements of the pp and p(bar)p elastic scattering spin observables at 16 GeV/c (direct reconstruction of elastic pp and p(bar)p elastic scattering amplitudes at SPASCHARM experiment). To date the direct reconstruction of amplitudes for pp elastic scattering was performed up to 6 GeV/c only, meanwhile there is no available data for p(bar)p elastics scattering. New measurements at SPASCHARM will significantly extend the energy range of the spin studies and will give unique possibility to compare elastic pp and p(bar5)p scattering

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In the Spring 2018, the first physics data was accumulated in the new SPASCHARM experiment at U-70 accelerator of IHEP, Protvino. The first stage of SPASCHARM’s physics programs prursues the goal of studying spin effects in the beam fragmentation region at an unpolarized negative 28 GeV beam, interacting with a frozen polarized proton target. In this resport, the feasibility of measuring the single spin asymmetry AN in the reaction: π − + p↑→K 0 S + X is evaluated by Monte-Carlo simulations. We present estimates of the detection efficiency as well as for expected event statistics. It is shown that, in the process of interest above, the attainable statistical errors for AN would be at the scale of a few percents.

The SPASCHARM experiment at U70 aims an exploration of a fundamental problem in modern particle physics, the role of spin in strong interactions. At present, the first physics data have been accumulated at a negative 28 GeV beam, interacting with a frozen polarized proton target. The SPASCHARM wide-aperture spectrometer can detect both charged and neutral particles in the large solid angle with 2π azimuthal coverage in the fragmentation region of beam-particles. It covers the kinematic region of non-perturbative quantum chromodynamics (QCD), where the theoretical predictions are difficult and unreliable due to the full strength quark confinement at low and medium momentum transfers. In this report, the current status of the experiment is presented. The algorithm for reconstructing charged tracks is discussed along with its results on real data and the comparison with the Monte Carlo (MC) simulations. Based on a real track reconstruction, the statistical errors for the measurements of single-spin asymmetries in inclusive charged pion production are estimated. The data analysis is in progress.

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