100 likes | 272 Views
Dielectrons from HADES to CBM. Properties of hadrons in strong int. matter: M, vs , m B , T, V SIS / GSI accelerator facility :heavy ion, proton, pion beams 0 r 3 r 0 0 T 80 MeV Vector meson , , spectral functions measurements
E N D
Dielectrons from HADES to CBM • Properties of hadrons in strong int. matter: M, vs , mB, T, V SIS / GSI accelerator facility :heavy ion, proton,pion beams • 0 r 3 r00 T 80 MeV • Vector meson , , spectral functions measurements • Hadron’s structure: em form-factors, vector meson-nucleon,interactions • Dalitz and two-body decays, pN, N reactions dielectrons ! Bratislava (SAS, PI), Catania (INFN - LNS), 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.)
Dielectrons: sensing probe • dielectron two-body decays ,g w p0 HI collisions c 10-15 fm/c e+ e- e+ ,p0 e- f ..and Dalitz decays N N* e+ e- BR ! ! Figure of merit
Beams@GSI for HADES pp->ppX Ethresh [GeV] / -p->Xn Mx [GeV/c2] • HI beams with E2 AGeV • p beam with I<1011 E<4.6 GeV • secondary beams • study elementary dielectron sources from pN and N reactions • Study in-medium vector meson properties in pA, A reactions
HADES@GSI beam coils META RICH 4.5m MDC I/II • Large acceptance : 200< <800, 0< < 2 35% for pairs (m >0.2 GeV/c2, pT>0.1 GeV/c) • e-,e+,p,identification • real-time lepton triggering • M=1-2% @ / ( 2003-> ) • operation with p, , HI beams (<2AGeV)
HADESin reality PreShower RICH RICH +MDC I Magnet
Electron identification C+C, 2AGeV e- e+ v/c e- e+ v/c + - p q*p [MeV/c] d RICH +Tracking +TOF/PreShower p*q [MeV/c] • hadron contamination <1% Tracking+TOF • p/ separation for p <1000 MeV/c
HADES electrontrigger • I First Level Trigger: • TOF multiplicity (Mch>3) • II Second Level Trigger Identification of electron candidates • Cherenkov rings • Shower hits • Time-of-flight Trigger Condition: 1 electron: (1 ring matched by TOF / Shower) Event Suppression: only 8% selected events (LVL2) • 60 VME boards • decision ~ 10 ms • process ~3 GByte/s raw data
C+C @2 AGeV 0e+e- Not acceptance corrected Preliminary Nov02 data scaled down by 10 Nov02(LVL2) Nov01(LVL1) Counts/MeV Me+e- [MeV/c2] • 10 times more pair statistics in the same running time • No bias on pair distributions • High resolution tracking with outer MDC’s
HADES @SIS200?: 8AGeV C+C • Simulation of production in C+C • emitted • detected acceptance • even without changing HADES geometry acceptance is similar Polar angle momentum [MeVc]