Vasilisa Lenivenko Vladimir Palichik (LHEP, JINR ) Alushta, June 2016

Physics possibilities at the Nuclotron Physics possibilities at the Nuclotron AGS NA49BRAHMS In A+A collisions at Nuclotron energies: In A+A collisions at Nuclotron energies:  Strange and multi-strange hyperon production at threshold Au+Au/Pb+Pb, central Nuclotron energies  Production of hypernuclei through coalescence of Λ with light fragments enhanced at high baryon densities  The energy range is well suited for the search of hypernuclei 2

setup DCHmRPC-2 GEM Central tracker (GEM) inside analyzing magnet to reconstruct AA interactions Outer tracker (DCH, Straw) behind magnet to link central tracks to ToF detectors ToF system based on mRPC chambers and T0 detectors to identify hadrons and light nucleus ZDC calorimeter to measure centrality of AA collisions and form trigger Detectors to form T0, L1 centrality trigger and beam monitors Electromagnetic calorimeter for γ,e+e- MWPC chambers will be used as beam trajectory detectors Target & T0 detector Analyzing magnet ZDC mRPC-1 Straw mRPC-2 DCH GEM 2 m Final setup 3

BM&N setup in first technical run in February-March 2015 ToF-700 Scint-700 ToF MWPC ToF-700 Scint-700 ZDC DCH-1,2 magnet ZDC Tasks for technical run: deuteron and C 12 beams with T 0 = 3.5 AGeV Trace beams, measure beam profile and time structure Test detector response: ToF-400, ToF-700, T0+Trigger detectors, DCH chambers, ZDC and ECAL modules, MWPC chambers Test integrated DAQ and trigger system 4

Location of MWPCs in technical runs 2015 MWPC layout Deutron Run2 (February, 2015) Carbon Run3 (March, 2015) 5 MWPC served as beam trajectory detectors in deutron Run2 and tracking detectors in carbon Run3

MWPC geometry of planes 6 6-plane working area

Track-segment building in the MWPC 7 track-segment candidate

8 X- V- U+ X+ V+ U- X- V- U+ X+ V+ U-

Segments matching between Chambers 2 & 3 in Carbon Run3 9

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MWPC detector system alignment Carbon Run3 geometry Z_Ch1= -150 cm; Z_Ch2 = 453 cm; Z_Ch3 = 486 cm; Alignment was done with data without magnetic field (B=0): Beam before target is oriented along Z-axis. After target charged particles are located around zero on Y-coordinate and there extrapolation to Z=0 on X-coordinate must be matched with beam (X=0). 11

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13 MWPCs efficiencies (deuteron Run2) Noisy layers: V+, U-, V- After magnet Eff per Ch(4/6) = 96.5 % Eff per Ch(4/6) = 98.3 % Eff per Ch(5/6) 63.5 % 61.0 % 59.0 % Before magnet

14 MWPCs efficiencies (Carbon Run3) Eff per Ch(4/6) 98.0 % 99.6 % Eff per Ch(4/6) 95.5 % 97.4 % 95.6 % 98.0 % Eff per Ch(5/6)

15 Matching of MWPC segments with DCH tracks By simulation

16 Extrapolation of track from DCH to MWPC ( Carbon Run 3 data ) MWPC

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BD – the scintillation-strip barrel detector The BD granularity is 40 channels and it consists of 40 scintillation strips BC- 418 with cross section of 7×7 mm2 and 150-mm length. In 2016 the nuclear interaction in the target is triggered by detection of charged particles in a range of polar angle 10° < θ < 150° using a new barrel detector (BD). 18 polar angle 13° < θ < 35°

Lambda–hyperon registration in modeling QGSM generator

ELoss, GeV Pz, GeV

Z = 0 – 15 cm Z = 16 – 31 cm Ecut=1 MeV Z = 8 – 23 cm Entries Pz, GeV Entries MinBias Ev MinBias Ev

Z = 0 – 15 cm Z = 16 – 31 cm Z = 8 – 23 cm Pz, GeV Z, cm Pz, GeV MinBias Ev MinBias Ev

Summary Track reconstruction algorithm was developed for MWPC chambers ►Track segment reconstruction for each MWPC ►Alignment of MWPC detector system ►Segment matching between chambers 2&3 ►Spatial fit by straight line in two MWPC Efficiencies per plane & per chamber were estimated We attempted to match MWPC segments with DCH tracks: we do not see correlation between MWPC & DCH tracks in Carbon Run due to different geometric layout of MWPC & DCH detector systems. 23

24 Thank you for your attention

Backup 25

experimental layout in Run3 with carbon beam Beam Monitor (BM), Multiwire Proportional Chambers (MWPC), Drift Chambers (DCH), Time of Flight (ToF), Zero Degree Calorimeter (ZDC) 26

Track-segment selecting 27

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