HADES Upgrade for DIRAC-Phase-1 P. Salabura Jagiellonian University Kraków, GSI Darmstadt

HADES GSI 20 institutions from 20 countries 1994 approved 2002 first production run

Physics runs conducted November 2002: C+C 2 AGeV, commissioning and physics runs 220 Mevents – two level trigger scheme (LVL1/LVL2)220 Mevents – 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 400 Mevents –LH 2 target400 Mevents –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) 650 Mevents  inclusive e+,e- production ("DLS enhancement" 650 Mevents 2200 Mevents September 2005: Ar+KCl 1.75 AGeV 2200 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 S/B>1 for M>140 MeV/c 2 Corrected for Reconstruction Efficiency Inside HADES geometrical acceptance, no extrapolation to 4  ! Compared with a cocktail based on known or m t -scaled meson multiplicities and their vacuum decay properties. Dielectrons from 2 AGeV

Exclusive meson reconstruction in 2.2 GeV pp→pp  →pp  +  -  0 pp→pp  →ppe + e -  00  Hadronic channels Electromagnetic channels pp→pp  0 →ppe+e-   =14 MeV/c 2 (pp  /e +  /e - ) missing mass vs (pp) missing mass distributions

future upgrades Needed for : (I) HI systems with at 1-2 AGeV A tot >80 (II) 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 RPC TOFINO:(time-of-flight between o) –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 HADES Gas mixture: 98.5% C 2 H 2 F 4 + 1% SF % i-C 4 H 10 Potential = 3 kV All full-size components produced and tested 30 months duration workplane details in talk of P. Fonte

HADES2-Forward 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  < 8 0

HADES3 – 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 (A tot >80) with large multiplicities (3) New Matching Unit for faster processing of second level trigger in large multiplicity environment essential for heavy systems (A tot >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 line  on p, A p, on p, d AA collisions DIRAC

Allocated 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 All Total

HADES collaboration 1)Institute of Physics, Slovak Academy of Sciences, Bratislava, Slovakia 2)Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Catania, Italy 3)Dipartimento di Fisica e Astronomia, Università di Catania, 95125, Catania, Italy 4)LIP-Laboratório de Instrumentação e Física Experimental de Partículas, Departamento de Física da Universidade de Coimbra, Coimbra, Portugal 5)Smoluchowski Institute of Physics, Jagiellonian University of Cracow, Cracow, Poland 6)Gesellschaft für Schwerionenforschung mbH, Darmstadt, Germany 7)Joint Institute of Nuclear Research, Dubna, Russia 8)Institut für Kernphysik, Johann Wolfgang Goethe-Universität, Frankfurt, Germany 9)II.Physikalisches Institut, Justus Liebig Universität Giessen, Giessen, Germany 10)Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano, Italy 11)Dipartimento di Fisica, Università di Milano, Milano, Italy 12)Institute for Nuclear Research, Russian Academy of Science, Moscow, Russia 13)Institute of Theoretical and Experimental Physics, Moscow, Russia 14)Physik Department E12, Technische Universität München, Garching, Germany 15)Department of Physics, University of Cyprus, 1678 Nicosia, Cyprus 16)Institut de Physique Nucléaire d'Orsay, CNRS/IN2P3, Orsay, France 17)Nuclear Physics Institute, Academy of Sciences of Czech Republic, Rez, Czech Republic 18)Institut für Kern- und Hadronenphysik, Forschungszentrum Rossendorf, PF , Dresden, Germany 19)Departamento de Física de Partículas. University of Santiago de Compostela Santiago de Compostela, Spain 20)Instituto de Física Corpuscular, Universidad de Valencia-CSIC,46971-Valencia, Spain

Comparison with transport theory RQMD calculation: D. Cozma, C. Fuchs and A. Faessler, Tübingen Filtered with HADES acceptance resolution smeared vacuum calculation in-medium calculation collisional broadening extended VDM + decoherence Brown-Rho scaling of VMs  See Phys. Rev. C68 (2003) for details.