Physics with p at the Future GSI Facility

1. Physics with p at the Future GSI Facility High Energy Storage Ring HESR • Physics program • Detector set-up p High luminosity mode Pmax = 1.5-15 GeV/c Lmax < 2·1032 cm-2 s-1 Δ p/p ~ 10-4 (stochastic cooling) e- cooler detector High resolution mode Pmax = 1.5-8 GeV/c Lmax 1031 cm-2 s-1 Δ p/p ~ 10-5 (electron cooling)

2. Charmonium spectroscopy Medium modifications of D mesons and J/Ψ in nuclei Hypernuclei Glueballs Hybrids CP violation Physics program

4. 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. Charmonium spectroscopy Crystal Ball e+e- 40 keV

5. Charmonium spectroscopy Crystal Ball e+e-

6. Signal: exotic quantum numbers: partial wave analysis normal quantum numbers: model comparison (LGT) Glueballs Hybrids mixing with normal mesons charm sector: few resonances with small widths Meson Hybrid Glueball ggg qq qqg 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

7. Glueballs Hybrids

8. Mass modifications of mesons pionic atoms π- 25 MeV π π+ KAOS/FOPI K+ K 100 MeV K- HESR D D- 50 MeV ? D+ vacuum nuclear medium ρ = ρ0 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).

9. _ X 3 GeV/c p X- Hypernuclei K+K Trigger • X-(dss)p(uud)L(uds)L(uds) • study of L L interaction secondary target

10. p + p → Λ +Λ ↓ ↓ pπ- pπ+ CP violation in Hyperon decay • Signal for CP violation: • Theoretical prediction: • Experiment: 1010 reconstructed ΛΛ • L=2·1032 cm-2 s-1 → >1 year running • 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

11. Angular acceptance Formation of Ψ’and decay in myons electrons similar → calorimeter for large angles. Ψ’→μ+μ- Ψ’→J/Ψ + X ↓ μ+μ-

12. HESR Detector target spectrometer forward spectrometer Internal target top view Heavy charmed mesons decay in light products with large pt. Solenoid is important.

13. Particle identification p+p → ΦΦ→ 4K s½ =3.6 GeV • Forward angles need π/K separation up to 3 GeV/c: Cherenkov n=1.02 • Backward: higher value of n.

15. 2 mio. forward pixels 100 x 150 μm 7.2 mio. barrel pixels 50 x 300 μm beam pipe pellet pipe Tracking, Micro Vertex Detector Readout: ASICs (ATLAS/CMS) 0.37% X0 or pixel one side – readout other side (TESLA)

16. σZ0=82 μm σD0=51 μm y z D0 Z0 x MVD, single track resolution p p 8.5 GeV 2π+ 2π- Vertex resolution is sufficient for D-physics c(D) = 314 μm, c(D0) = 124 μm

17. pp(s = 4.4 GeV/c2)  J/+f. Target spectrometer, momentum resolution MVD straw tubes MDC σM= 1.2% ???

18. 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

19. pp(s = 4.4 GeV/c2)  J/+f. Particle identification

20. Calorimeter 22o 140o 5o PbWO4 Length = 17 X0 APD readout (in field) σ(E) = 1.54% / E½ + 0.3% (PM) pp  J/Ψ+η γγ

21. 10 e±/π±sep. 8 e+/- 6 Edep (GeV/c) 4 2 π+ 0 2 4 6 8 p (GeV/c) π+ probability 10-3 electron/pion separation  10-3 0 2 4 6 8 p (GeV/c)

22. Pellet target 1 mm • Frozen hydrogen pellets 20-40μm • Δx=±1 mm (±0.04o) • 60 m/s • 70000 pellets/sec. • 1014-1016 atoms/cm2 (avg.)