CBM and FRRC

Mikhail Ryzhinskiy, SPbSPU(on behalf of Russian CBM branch)

1st FRRC International Seminar

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SIS 300 → U92+ 15-35 GeV/nucleon with beam intensities up to 109/s

Z/A = 0.5 nuclei up to 45 GeV/nucleon

→ exploration of the QCD phase diagram with heavy-ion collisions!

→ investigation of nuclear matter at highest baryon densities but still moderate temperatures in A+A collisions

Compressed Baryonic Matter experiment

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What is the equation-of-state of strongly interacting matter? (core collapse supernovae, neutron stars, early universe)

What is the structure of strongly interacting matter as a function of T and ρB ? (hot and dense hadronic medium, deconfined phase, phase transitions ?)

What are the in-medium properties of hadrons as a function of T and ρB ? (partial restoration of chiral symmetry ?)

Fundamental Questions of QCD

compression + heating = QGP ?

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DipolmagnetJINR

The Compressed Baryonic Matter Experiment

Ring ImagingCherenkovDetectorIHEP, PNPI

Transition Radiation DetectorsJINR, PNPI

ResistivePlate Chambers(TOF)INR, IHEP

ECALITEP, IHEP

SiliconTrackingStationMSU, MEPHI,JINR, IHEP,Khlopov, CKBM

Tracking Detector

Muondetection SystemPNPI

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• Sergei Belogurov (ITEP) PhD – Design and Integration of the CBM experiment• Mikhail Ryzhinskiy (SPbSPU) PhD – Advanced Digitization and Cluster Finding in

MUCH• Alexander Sadovsky (INR) PhD – Event-by-event Fluctuations at CBM Experiment• Andrei Chernogorov (ITEP) – Design Justification of ECAL• Olga Denisova (JINR) – Development of New Mathematical Methods for

Experimental Data analysis• Alexander Dermenev (INR) – Study of Projectile Spectator Detector for Centrality

and Reaction Plane Determination • Dmitry Golubkov (ITEP) - Optimization of CBM ECAL for χc States Production

Studies• Alexander Klyuev (MEPhI) - Development or Data-driven, De-randomizing

Architecture and Building Blocks for the CBM-XYTER ASIC • Eugeny Kryshen (PNPI) – MUCH Design and Construction, Software

Development• Mikhail Prokudin (ITEP) - Development of CBM ECAL Software• Georgy Sharkov (ITEP) - Comparison of ω and φ Meson Cross Sections,

Measured in Different Decay Modes using CMMROOT Simulations• Taras Vasiliev (JINR) - Participation in the R&D of TRD and Development of

Software for Selection of Strange Particles in Nucleus-Nucleus Collisions• Vladislav Zryuev (JINR) - Research and Development of Fast and High

Resolution Gaseous Detectors for CBM

List of candidates for FRRC grants from the Russian Institutes

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A number of polarization observables have been proposed as a possible signature of phase transition in heavy ion collisions:

• Decreasing of the Λ0 transverse polarization in central collisions • Global hyperon polarization in non-central events

The study of the polarization effects at CBM requires good definition of the reaction plane RP and collision centrality b.

Kinematical fit using ASME method for STS(Au+Au centr.coll. 25 AGeV, via UrQMD, GEANT3 m.field) improves accuracy of the primary vertex determination spatial approx. 20 microns (P_V0, beta, tan(alpha)) : better than (1%,0.5 mrad, 0.3)

Polarization in HI collisions as a new probe of the phase-transition (T.Vasiliev, Dubna group)

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Research and development of fast gaseous detectors for TRD CBM (V.Zryuev, LHEP JINR,

Dubna)

• High granularity• Spatial resolution < 300µm• High rate capability • high-speed detector (for the inner part of the detector planes)

Main requirements for TRD detectors• High radiation hardness• Minimum material budget• Optimal number of electronic channels

The results obtained with GEM based detector• Spatial resolution is ~ 90 µm for 600µm strip pitch• Good linearity ~ 1%• Amplification factor ~ 2 x10³.

The results obtained with THGEM based detector • Spatial resolution is ~ 230 μm fot 1 stage THGEM detector• We are working on the technology for construction of THGEM

patterns (holes and rims) with a high precision.• FEE with n-Xyter chip is planning to use for further tests.

R&D work show that both GEM and THGEM detectors require a lot of work to improve its reliability and stability to use them in a large system like CBM.

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Layout of the detector installation on the beam line SYS-18 GSI

We have performed a systematic study of several types of gas MWPC detectors at high intensity beams at GSI .

The R&D of the MWPC detectors shows practically no degradation of the signal amplitudes up to the rate of 360 kHz/cm2. Taking into account the high spatial resolution (< 200 μm) and the operational stability of the MWPC detector as well as the results obtained on its high rate capability in our research we believe that this type of detector meets all requirements to TRD of the CBM project.

The results obtained with MWPC based detector

φ e-

hadronization Kinetic freeze-out

φη η

e+

φK+

K+

K-φ

ω

l,fm

β= 1/3

e+e-

If resonance decays before in dense barionic matter Possible rescattering of hadronic daughters Reconstruction probability decrease for hadronic mode

ω(782) π+π-π0, π+π-, π0 (c = 23 fm)

φ(1020) K+K-, η, e+e- (c = 44 fm)

and ω resonance decay modes (G.Sharkov, ITEP)

10Gray – MC. Black – data. Scale!

Near fibers LHCb inner. 4mm

Prototype. 0.5 mm1cm 1cm1cm

Near fibers

Shower library•Fits exactly to the data•Any incident angle•checking analytical approximation quality

Calorimeter simulation and reconstruction (M.Prokudin, ITEP)

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Advanced digitization and hit finding in MUCH (M.Ryzhinskiy, SPbSPU)

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On e/ identification: comparision of TRD prototype measurements with GEANT simulation at p=1.5 GeV/c (O.Denisova, JINR)

•One cannot get a maximal value of pion’s suppression when using the LFR test, because the electron energy losses are described by a complex hypothesis – the sum of two distributions.•Using GEANT simulations were reproduced the results obtained on the basis of real measurements, and there was demonstrated that the procedure of preparation of data sets based on real measurements is a reason of getting erroneous, overestimated results

Time schedule

Time schedule