Drift chamber calibration and particle identification in the P-349 experiment

D Alfs,T Sefzick,F Hauenstein,D Lersch,S Malbrunot-Ettenauer,W Eyrich,H Mkrtchyan,D Grzonka,W Oelert,A Zink,A Mkrtchyan,S Zhamkochyan,J Ritman,M Diermaier,A Asaturyan,M Carmignotto,V Tadevosyan,K Kilian,E Widmann,B Głowacz,P Moskal,J Zmeskal,Marcin Zieliński ,T Horn,M Wolke,P Nadel-Turoński

doi:10.1051/epjconf/201919905017

Abstract

The goal of the P-349 experiment is to test whether 3.5 GeV/c antiprotons produced in high-energy proton-proton collisions are polarized in view of the preparation of a polarized antiproton beam. In this article, we present the details of the ongoing analysis focused on the drift chambers calibration and particle identification with DIRC.

Highlights

The experimental determination of the antiproton polarization in the P-349 experiment 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 [1, 2]
Tracking is done with a set of three drift chambers [4]: one drift chamber with 7 layers of hexagonally shaped cells (HEX, three layers with vertical wires, two double layers with wires inclined under ±11o) placed in front of the scattering target and a package of two drift chambers with rectangular cells (D1, D2) for the scattered particles
The preliminary PID determined from the DIRC photon distributions for an event sample with the aerogel Cherenkov detector veto on and off is shown in the Fig. 2 middle and right, respectively, where separate maxima corresponding to the antiprotons and pions are visible

Summary

Introduction

The experimental determination of the antiproton polarization in the P-349 experiment 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 [1, 2]. The experiment was performed in the CERN/PS test beam East Area. The secondary beam of positively charged particles with momentum equal to 3.5 GeV/c was delivered to the experimental setup in the form of 400 ms long spills. The experimental setup was designed to provide a precise tracking, online suppression of the dominant pionic background and reliable offline antiproton identification. For further information see [1, 3]

Track reconstruction

Particle identification

Summary and outlook