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Physics with p at the Future GSI Facility • • Physics program Detector set-up p High Energy Storage Ring HESR e- cooler High luminosity mode Pmax = 1.5-15 GeV/c Lmax < 2·1032 cm-2 s-1 Δ p/p ~ 10-4 (stochastic cooling) detector High resolution mode Pmax = 1.5-8 GeV/c Lmax 1031 cm-2 s-1 Δ p/p ~ 10-5 (electron cooling) STORI’02 Carsten Schwarz Physics program Glueballs Hybrids Charmonium spectroscopy Medium modifications of D mesons and J/Ψ in nuclei CP violation STORI’02 Hypernuclei Carsten Schwarz James Ritman Univ. Giessen STORI’02 Carsten Schwarz • Charmonium spectroscopy • • • • Charmonium gives information about QCD confinement potential. Many states are still missing. pp: direct formation of all states. HESR allows investigation of states above DD threshold. Cooled beams with Δp/p=10-4…10-5 allow high precision scan of resonances. Crystal Ball e +e - 40 keV STORI’02 Carsten Schwarz Charmonium spectroscopy STORI’02 Crystal Ball e +e - Carsten Schwarz Meson Hybrid Glueball qq qqg ggg Glueballs Hybrids Normal meson: 2 fermions P = (-1)L+1 C = (-1)L+S Excited glue: bosonic degree of freedom → exotic quantum numbers eg. JPC=1-+, 0--, 0+-, 2+-… → normal quantum numbers STORI’02 Signal: exotic quantum numbers: partial wave analysis normal quantum numbers: model comparison (LGT) mixing with normal mesons charm sector: few resonances with small widths Carsten Schwarz Glueballs Hybrids STORI’02 Carsten Schwarz Mass modifications of mesons Medium modifications of D mesons and J/Ψ in nuclei Continuation of present GSI physics FOPI, KAOS, HADES, …HESR Signal: medium modification of production threshold, resonance width e.g. Ψ’, χ2 Absorption cross section of J/Ψ in nuclei (ρ=ρ0). STORI’02 pionic atoms π KAOS/FOPI K π25 MeV π+ K+ 100 MeV HESR D vacuum KD50 MeV ? D+ nuclear medium ρ = ρ0 Carsten Schwarz Hypernuclei K+K Trigger p _ X 3 GeV/c X- X-(dss) p(uud) L(uds) L(uds) study of L L interaction secondary target STORI’02 Carsten Schwarz CP violation in Hyperon decay • p + p → Λ +Λ ↓ ↓ pπ- pπ+ • • • • Measure decay asymmetry of angular distribution of p relative to Λ-Hyperon momentum. Ip(θp) ~ 1+α cos(θp) for Λ Ip(θp) ~ 1+α cos(θp) for Λ CP conservation: α = - α STORI’02 Signal for CP violation: Theoretical prediction: A 10-4 ... 10-5 Experiment: 1010 reconstructed ΛΛ L=2·1032 cm-2 s-1 → >1 year running Carsten Schwarz Angular acceptance Formation of Ψ’ and decay in myons electrons similar → calorimeter for large angles. Ψ’→μ+μ- Ψ’→J/Ψ + X ↓ μ+μSTORI’02 Carsten Schwarz HESR Detector target spectrometer forward spectrometer Internal target top view Heavy charmed mesons decay in light products with large pt. Solenoid is important. STORI’02 Carsten Schwarz Particle identification p+p → ΦΦ→ 4K • • s½ =3.6 GeV Forward angles need π/K separation up to 3 GeV/c: Backward: higher value of n. STORI’02 Cherenkov n=1.02 Carsten Schwarz STORI’02 Carsten Schwarz Tracking, Micro Vertex Detector 2 mio. forward pixels 100 x 150 μm 7.2 mio. barrel pixels 50 x 300 μm pellet pipe beam pipe Readout: ASICs (ATLAS/CMS) 0.37% X0 or pixel one side – readout other side (TESLA) STORI’02 Carsten Schwarz MVD, single track resolution σD0=51 μm σZ0=82 μm pp 8.5 GeV 2π+ 2π- y z D0 Z0 x STORI’02 Vertex resolution is sufficient for D-physics c(D) = 314 μm, c(D0) = 124 μm Carsten Schwarz Target spectrometer, momentum resolution MVD straw tubes MDC σM= 1.2% ??? pp(s = 4.4 GeV/c2) J/f. STORI’02 Carsten Schwarz Particle identification • PID from – 00<Θ<50 hadronic calorimeter – 50<Θ<220 Aerogel Cherenkov Counters – 220<Θ<1400 DIRC (BABAR@SLAC) DIRC thickness: 0.19 X0 STORI’02 Carsten Schwarz Particle identification STORI’02 pp(s = 4.4 GeV/c2) J/f. Carsten Schwarz Calorimeter 22o o 140 5o PbWO4 Length = 17 X0 APD readout (in field) σ(E) = 1.54% / E½ + 0.3% (PM) pp J/Ψ + η γγ STORI’02 Carsten Schwarz Edep (GeV/c) e±/π± sep. 10 8 e+/- 6 4 π+ 2 0 2 4 6 8 p (GeV/c) π+ probability 10-3 electron/pion separation 10-3 0 STORI’02 2 4 6 8 p (GeV/c) Carsten Schwarz Pellet target 1 mm • • • • • STORI’02 Frozen hydrogen pellets 2040μm Δx=±1 mm (±0.04o) 60 m/s 70000 pellets/sec. 1014-1016 atoms/cm2 (avg.) Carsten Schwarz