1 high acceptance di-electron spectrometer the activity of jinr for hades project is performed in...

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High Acceptance Di-Electron Spectrometer

The activity of JINR for HADES project is performed in frame of theme 03 -1 - 1020 - 96/2005 with a first priority.

Leader from JINR: Yu. Zanevsky

Institutes of Germany:GSI (Darmstadt), University (Frankfurt), Technical University (München), University (Giessen), Forschungzentrum (Rossendorf)

Laboratories of JINR: VBLHE, BLTP

_________________________________________________________ http:// www-hades.gsi.de http:// lhedl.jinr.ru

5th Workshop on the Scientific Cooperation between German Research Centers and JINR, 17-19 January, 2005

http://www.hades-gsi.de/

http://www.hades-gsi.de/

http://lhedl.jinr.ru/

http://lhedl.jinr.ru/

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HADES detector is designed to provide an excellent mass-resolution (~1 %) and very large acceptancefor comprehensive studies of the behavior of , and - mesons in the nuclear medium.

TOFINO

Magnet

SC toroid ( 6 coils) in

Lepton Identification

RICH C4F10 + gas Phot. Det. CsI - cathode

META TOF scintillator wall + Pre-Shower detector

Tracking

p – measurement

vertex reconstruction

MDC Drift chambers cell size cm x ~ 100 m

()


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• Bratislava (SAS, PI)• Catania (INFN - LNS)• Clermont-Ferrand (Univ.)• Cracow (Univ.)• Darmstadt (GSI)• Dresden (FZR)• Dubna (JINR)• Frankfurt (Univ.)• Giessen (Univ.)• Milano (INFN, Univ.)• Moscow (ITEP, INR, MEPhI)• Munich (Tech. Univ.)• Nicosia (Univ.)• Orsay (IPN)• Rez (CAS, NPI)• Sant. de Compostela (Univ.)• Valencia (Univ.)

HADES collaborationHADES collaboration


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3D sketch of the HADES spectrometer, split along the longitudinal direction for clarity. In operating conditions all the shown elements fit into each other making the whole structure much more compact.



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• Full-size Prototype of multilayer Drift Chamber has been developed and tested

• Front End Electronics for Drift Chambers has been developed and tested.

• Six low mass multilayer Drift Chambers (plane 2) were constructed, tested and integrated into the HADES spectrometer.

• Track reconstruction software has been developed and successfully applied for data analysis

( ‘ Dubna Tracking Software ’ ).

• Participation in physical program and data analysis.

Main items of JINR activity for HADES


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Full-size Drift Chambers Prototype

Assembling of Prototype at JINR Testing of Prototype on the beam at GSI

The results of the test were very successful:

- High spatial resolution (~ 70 μm) and high efficiency with gas mixture He + Isobutan.

- Long term stable operation.


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Front End Electronics for HADES Drift Chambers

The last test of Front End Electronics before installation into Magnet

Very important parts - flat cables with 16-channels Ampl/Discr Cards

Front End Electronics for HADES Drift Chambers has been developed

and tested by JINR team.


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Drift Chambers - assembling and installation

6 multilayer Drift Chambers (plane 2) were constructed and tested in Dubna.After the assembling and testing in HADES cave the Drift Chambers wereinstalled into Magnet and the Commissioning has been started.


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Track reconstruction software for HADES


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Spatial Resolution of HADES Drift Chambers

C. Muentz, Report on Vienna Instrum. Conference, Febr. 2004 Published in Nucl. Instr. Meth. 535 (2004), 242–246


Yuri Zanevsky

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Momenta Resolution for 2, 3 and 4 Momenta Resolution for 2, 3 and 4 Drift Chambers planes Drift Chambers planes

Res

olu

tion

[%

]

p5th Workshop on the Scientific Cooperation between German Research Centers and JINR, 17-19 January, 2005

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DETECTOR STATUS

From the Report of P. Salabura on PAC / GSI, September 2004


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Data Analysis and Experimental Program -During the production beamtimes of 2002 - 2004 were collected : ~ 210 mio events C+C@ 2,2 AGev (2002) ~ 500 mio events C+C@ 1,0 AGev (2004) ~ 400 mio events p+p@ 1-2,5 Gev (2004) Data analysis is in progress

-Development of further physical program on SIS and on future accelerator facility FAIR (A + A at 2-8 AGev).

Nearest Physical Program

1. Dielectrons from pp/pd 2. On threshold η production in d+p 3. ω production in pp collisions 4. Dielectrons from Ca+Ca

The results will be discussed on the next HADES Collaboration Meetingin Dubna, 7-12 June 2005.


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Preliminary

Data Analysis: Dielectrons, Vector Mesons

Simulation: Ca+Ca @ 2.2 AGev ΔP/P is improved up to ~ 2 % (with outer Drift Chambers were installed in HADES Spectrometer).

Experimental data: C+C @ 2.2AGeV Nov’2002Spectrum of effective mass of e+ e¯ pair (red color). There is a good agreement with simulation (outer Drift Chambers were not installed, ΔP/P is ~ 8%).

M [GeV/c²]


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1. Simulation of pp interactions at various energies (including electromagnetic decay of hadrons).

2. Track reconstruction and momentum determination software.

3. On-line and off-line vertex reconstruction.

4. “Event Display” program (a first version), monitoring of drift chambers data quality.

5. Participation in the commissioning, HADES experimental program and data analysis:

- C+C (1.5-2.0 AGeV)

- p+p (1.5-2.2 GeV)

6. Participation in development of the ALIGNMENT software.

The work is supported by INTAS grant No. 03-51-3208 for HADES

and grants of JINR/BMBF Committee

Main items of JINR team activity in 2002-2004


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Event display

The software has been developed by P. Biriukov from LIT (JINR)


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Online vertex reconstruction (Nov02 data)


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• The HADES spectrometer offers a unique possibility for systematic studies of the light vector meson mass distributions inside nuclear matter by means of di-electron spectroscopy. • Recent results from commissioning runs confirmed the expected superior on-line and off-line electron identification capabilities. In particular, a high-statistics run with LVL2 trigger provided first pair data from C+C reactions at 2 AGeV.

• High resolution di-electron spectroscopy becomes now also possible, after the completion of the outer MDC tracking system.

• The full experimental program is planned for several years. First experiments aiming at the exclusive meson reconstruction in proton-proton reactions have been started in 2004. High resolution studies of the vector meson production in pion induced reactions and light

nucleus-nucleus system are planned in next 2-3 years.

• The HADES experimental program for FAIR (2-8 AGev) is under development.

• The JINR activity for HADES project was very appreciated in the recommendations of JINR/BMBF Committee and previous Workshops on the Scientific Cooperation between German Research Centers and JINR.

CONCLUSIONS


1 high acceptance di-electron spectrometer the activity of jinr for hades project is performed in...

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