The goal of the P-349 experiment is to determine polarization of antiprotons produced in pA collisions [1]. Experimentally this is done by the measurement of the left-right asymmetry of elastic antiproton scattering on a liquid hydrogen target in the Coulomb-nuclear interference region.

According to preliminary calculations, the maximum of the analyzing power ${A_y}$ equal to about -4.5% is reached for a four-momentum transfer $\vert t \vert = 0.003$ GeV/c [2] which corresponds to a scattering angle in the laboratory frame in the range of 10 - 20 mrad. Therefore, the required track reconstruction precision expected to be sufficient for the asymmetry determination is equal to about 1 mrad.

The experiment was performed in the PS test beam East Area, CERN in 2014 and 2015 and the data analysis is ongoing [3]. Currently, the main goals are reaching the desired track reconstruction precision and elimination of the dominant pionic background.

In this contribution the current status of the analysis will be presented with a focus on the drift chambers calibration, track identifiaction and reconstruction and particle identification with DIRC.

1. D. Grzonka et al., Acta Phys. Pol. B 46, 191 (2015).

2. J. Haidenbauer, private communication.

3. D. Alfs et al., Acta Phys. Pol. B 48, 1938 (2017).