HADES

Upgrade for DIRAC-Phase-1

P. Salabura

Jagiellonian University Kraków, GSI Darmstadt

HADES detector @ GSIHADES detector @ GSI

20 institutions from 20 countries

1994 approved

2002 first production run

Physics runs conductedPhysics runs conducted

November 2002: C+C 2 AGeV, commissioning and physics runs – two level trigger scheme (LVL1/LVL2) 220 220

MeventsMevents

– full coverage with inner MDCI/II, 2 sectors complete tracking (MDCI-IV)

inclusive e+,e- production ("DLS enhancement")

February 2004: p+p 2.2 GeV

– LH2 target 400 400

MeventsMevents

– complete tracking in 4 sectors, 2 sectors with MDC(I-III)

exclusive meson reconstruction

August 2004: C+C 1AGeV– complete tracking in 4 sectors, 2 sectors with MDC(I-III)

inclusive e+,e- production ("DLS enhancement" 650 Mevents650 Mevents

September 2005: Ar+KCl 1.75 AGeV 2200 Mevents2200 Mevents

– complete tracking in 4 sectors, 2 sectors with MDC(I-III)

inclusive e+,e- production: vector mesons in medium

M/M()= 10%.no outer tracking

within acceptance

16k signal pairs @ S/B>1 for M>140 MeV/c2

Corrected for Reconstruction Efficiency

Inside HADES geometrical acceptance, no extrapolation to 4!

Compared with a cocktailbased on known or mt-scaledmeson multiplicities and theirvacuum decay properties.

Dielectrons from C+C @ 2 AGeVDielectrons from C+C @ 2 AGeV

Exclusive meson reconstruction in pp @ 2.2 GeVExclusive meson reconstruction in pp @ 2.2 GeV

pp→pp→pp+-0• pp→pp→ppe+e-

0

Hadronic channelsElectromagnetic channels

• pp→pp0→ppe+e-

=14 MeV/c2

(pp/e+/e-) missing mass vs (pp) missing mass distributions

future upgradesfuture upgrades

Needed for :

(I) HI systems with at 1-2 AGeV Atot>80

(II) HADES @ FAIR (8AGeV)

(III) High intenisty pion beams

• RPC (inner time-of-flight) → essential for HI, important for elementary channels with strangeness production (/K separation)

(FP6 construction -> P. Fonte)

• Forward hodoscope → essential for p+d, important for HI

(FP6 construction-> H. Stroebele)

• Pion tracking → essential for +p, +HI

• DAQ → essential for HI (FP6 construction-> M. Traxler)

HADES1-TOFINO replacement by RPCHADES1-TOFINO replacement by RPC•TOFINO:(time-of-flight between 180 -45o)

– 4 paddles per sector only

– limited resolution (450 ps)

– insufficient granularity for HI

TOFINO

target

RPC:

180 cells/sector (double hit<10% for 1.0 AGeV Au+Au)

time resolution < 100 ps

Granularity:

1080 cells

operational parameter matched to HADES overall performance

• granularity: double-hit probability below 10%

• resolution: 100 ps (s) or better

• rate capability: up to 600 Hz/cm2 (at forward)efficiency: above 95% for single hits

concept of the design: • shielded single cells• 4 gaps with commercial glass 2mm thick• common gas box sector-wise• customized read-out: FEE (preamp, discriminator, TimeOverThreshold) + TDC (128 channels) based on HPTDC & CPU with fast ethernet

RPC for HADESRPC for HADES

Gas mixture:

98.5% C2H2F4

+ 1% SF6

+ 0.5% i-C4H10

Potential = 3 kV

• All full-size components produced and tested 10.05 @GSI

•30 months duration workplane details in talk of P. Fonte

HADES2-HADES2-Forward hodoscopeForward hodoscope

• Collective observables for dilectron production in HI collisions (flow)

event plane determination

measurement of reaction centrality

• Spactator tagging for d+p reactions

direct comparison of dielectron production in pp and p+n reactions

Upgrade of old and well known KAOS FH:

• inspection of detectors (380 modules), new reflecting cover for light guides, mainframe modifications

• new digital (TDC) electronic – same as used for the RPC

• new HV and slow control system

•Total project duration 12 months → see talk of H. Stroebele for workplan details

Acceptance for charge particles with < 80

HADES3 – DAQ upgradeHADES3 – DAQ upgrade

(1) Exchange of CPUs for event building for more efficient transport of large events.

• x86 CPUs running under LINUX and featuring GIGAbit Ethernet• successfully tested in the last Ar+KCl beam time

(2) New Image Processing Unit for Time of Flight and RPC detector• essential for heavy systems (Atot >80) with large multiplicities

(3) New Matching Unit for faster processing of second level trigger in large multiplicity environment

• essential for heavy systems (Atot>80 ) with large multiplicities

• Final goal is to reach 20 KHz LVL1 trigger rate (presently 7kHz)

Total duration 26 months → see talk of M. Traxler for workplan details

time linetime line

2005 2006 2007

2008

on p, A

p, on p, d

AA collisions

DIRAC

Allocated man power and investmentAllocated man power and investment

• 5 institutions: GSI Darmstadt, Institute fuer Kernphysik Frankfurt (IKF), Jagiellonian University (JU) Kraków, University Santiago de Compostella (USC), Laboratório de Instrumentação e Física Experimental de Partículas (LIP) Coimbra, Nuclear Physics Institute (INR) Rez, Institute for Nuclear Reasearch Moscow

•3 tasks: HADES1-RPC (P.Fonte), HADES2-FH (H.Stroebele), HADES3-DAQ (M. Traxler)

Man power : DIRAC Investment (k€): DIRAC

All321721321326096129

Total 570 130 100

HADES collaborationHADES collaboration1)Institute of Physics, Slovak Academy of Sciences, 84228 Bratislava, Slovakia2)Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, 95125 Catania, Italy3)Dipartimento di Fisica e Astronomia, Università di Catania, 95125, Catania, Italy4)LIP-Laboratório de Instrumentação e Física Experimental de Partículas, Departamento de Física da Universidade de Coimbra, 3004-516 Coimbra, Portugal5)Smoluchowski Institute of Physics, Jagiellonian University of Cracow, 30059 Cracow, Poland6)Gesellschaft für Schwerionenforschung mbH, 64291 Darmstadt, Germany7)Joint Institute of Nuclear Research, 141980 Dubna, Russia8)Institut für Kernphysik, Johann Wolfgang Goethe-Universität, 60486 Frankfurt, Germany9)II.Physikalisches Institut, Justus Liebig Universität Giessen, 35392 Giessen, Germany10)Istituto Nazionale di Fisica Nucleare, Sezione di Milano, 20133 Milano, Italy11)Dipartimento di Fisica, Università di Milano, 20133 Milano, Italy12)Institute for Nuclear Research, Russian Academy of Science, 117312 Moscow, Russia13)Institute of Theoretical and Experimental Physics, 117218 Moscow, Russia14)Physik Department E12, Technische Universität München, 85748 Garching, Germany15)Department of Physics, University of Cyprus, 1678 Nicosia, Cyprus16)Institut de Physique Nucléaire d'Orsay, CNRS/IN2P3, 91406 Orsay, France17)Nuclear Physics Institute, Academy of Sciences of Czech Republic, 25068 Rez, Czech Republic18)Institut für Kern- und Hadronenphysik, Forschungszentrum Rossendorf, PF 510119, 01314 Dresden, Germany19)Departamento de Física de Partículas. University of Santiago de Compostela. 15782 Santiago de Compostela, Spain20)Instituto de Física Corpuscular, Universidad de Valencia-CSIC,46971-Valencia, Spain

Comparison with transport theoryComparison with transport theory

RQMD calculation: D. Cozma, C. Fuchs and A. Faessler, Tübingen

Filtered with HADES acceptanceresolution smeared

vacuum calculation in-medium calculation

collisional broadeningextended VDM + decoherenceBrown-Rho scaling of VMs

See Phys. Rev. C68 (2003) 014904 for details.