Drift chambers in BM@N Experiment

Ján Fedorišin,S Bondarenko,V Burov,A Malakhov

doi:10.1051/epjconf/201713811005

Ján Fedorišin, S Bondarenko + Show 2 more

Open Access

https://doi.org/10.1051/epjconf/201713811005

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Abstract

Drift chambers (DCH) constitute an important part of the tracking system of BM@N experiment designed to study the production of baryonic matter at the Nuclotron energies.The method of particle hit and track reconstruction in the drift chambers is proposed and tested on the BM@N deuteron beam data.In first step, the radius vs drift time calibration curve is estimated and applied to calculate DCH hit closest approach coordinates. These coordinates are used to construct hits in each DCH under the assumption of track linearity. Hits in both the DCHs are subsequently aligned and fitted to produce global linear track candidates. Eventually the hit and track reconstruction is optimized by the autocalibration method. The coordinate resolutions are estimated from Gaussian fits of the DCH hit residual spectra for different DCH planes. Furthermore, the deuteron beam momentum value is reconstructed in order to check reliability of the employed track reconstruction algorithm.

Highlights

BM@N (Baryonic Matter at Nuclotron) [1] is a fixed target experiment at the JINR NICA-Nuclotron complex proposed to study the hot compressed nuclear matter produced in collisions of relativistic heavy nuclei with emphasis on strange matter production
Once the y,x,u,v coordinates are calculated using the distances of closest approach (DCA) provided by the calibration, the missing transverse coordinates in all the Drift chambers (DCH) planes are evaluated by solving the set of linear equations as described in [3]
The hit residual spectra obtained by integration of figure 2 distributions along drift time axes are presented in figure 4

Summary

Introduction

BM@N (Baryonic Matter at Nuclotron) [1] is a fixed target experiment at the JINR NICA-Nuclotron complex proposed to study the hot compressed nuclear matter produced in collisions of relativistic heavy nuclei with emphasis on strange matter production. Each DCH consists of four segments measuring different track coordinates in a transverse plane relative to the beam axis. The directly measured experimental observables are the electron drift times that are subsequently by the proper calibration technique [3, 6,7,8] converted to the distances of closest approach (DCA) of tracks to the anode wires. Once the y,x,u,v coordinates are calculated using the DCAs provided by the calibration, the missing transverse coordinates in all the DCH planes are evaluated by solving the set of linear equations as described in [3]. The track candidates from both the drift chambers are combined and fitted by straight lines to produce the global track candidates

DCH autocalibration

Results

Consistency check of the track reconstruction algorithm

Summary