James Ritman Univ. Giessen PANDA: An Experiment To Investigate Hadron Structure Using Antiproton Beams Overview of the GSI Upgrade Overview of the PANDA Physics Program Exotic Hadrons in the Charm Mass Region HESR: High Energy Storage Ring The PANDA Detector

James Ritman Univ. Giessen The GSI Future Project Heavy Ion Physics: hot and dense nuclear matter Nuclear Structure: paths of nucleo-synthesis Ion and laser induced Plasma: very high energy densities Atomic physics: QED, strong EM fields, Ion-Matter interactions Physics with Antiprotons properties of the strong force Project approved Feb 2003

James Ritman Univ. Giessen What Do We Want To Know? Why don‘t we observe isolated quarks? Q-Q potential in the charmonioum system Are there other forms of hadrons? e.g. Hybrids qqg or Glueballs gg Why are hadrons so much heavier than their constituents? p-A interactions

James Ritman Univ. Giessen Why Don’t We See Isolated Quarks?

James Ritman Univ. Giessen Charmonium – the Positronium of QCD 3 D  c (3590)  c (2980) h c (3525)  (3097)  (3686)  (3770)  (4040)  0 (3415)  1 (3510)  2 (3556) 3 D 1 3 D 3 1 D 2 3 P 2 (~ 3940) 3 P 1 (~ 3880) 3 P 0 (~ 3800) 1 fm C C ~ 600 meV S S S S P P P P S D D D D 2 Ionisationsenergie 3 3 S 1 e + e nm Binding energy [meV] Mass [MeV] Threshold 8·10 -4 eV eV Positronium Charmonium

James Ritman Univ. Giessen Probe large separations with highly excited qq states _ Charmonium Spectroscopy

James Ritman Univ. Giessen Open Questions  ` c (3590) Partial width mostly unknown Precision spectroscopy confirm h c Little is known about states above DD

James Ritman Univ. Giessen Why Antiprotons? e+e- annihilation via virtual photon: only states with J pc = 1 -- In pp annihilation all mesons can be formed Resolution of the mass and width is only limited by the beam momentum resolution Measured rate Beam Resonance cross section CM Energy

James Ritman Univ. Giessen High Resolution Crystal Ball: typical resolution ~ 10 MeV Fermilab: 240 keV   p/p < needed

James Ritman Univ. Giessen Why Are Hadrons So Heavy?

Hadron Masses Protons = (uud) ? 2M u + M d ~ 15 MeV/c 2 M p = 938 MeV/c 2 (P.Kienle) no low mass hadrons (except , K,  ) spontaneously broken chiral symmetry

Spontaneous Breaking of Chiral Symmetry Although the QCD Lagrangian is symmetric, the ground state need not be. (e.g. Fe below T Curie ) Example:

James Ritman Univ. Giessen Quark Condensate The QCD vacuum is not empty Hadron masses are generated by the strong interaction with (also with gluon condensate) The density of the quark condensate will change as a function of temperature and density in nuclei. This should lead to modifications of the hadron’s spectral properties.

Hadrons in the Nuclear Medium Spectral functions W.Peters et al., Nucl. Phys. A632, 109 (1998).S.Klimt et al., Nucl. Phys. A515, 429 (1990). Reduction of

Hadron Production in the Nuclear Medium c d _ d d u c _ d repulsive attractive D-D- D+D+ d d u d d u d d u d d u d d u  Quark atom Mass of particles may change in dense matter

James Ritman Univ. Giessen Advantages of p-A Reactions Compared to A-A Much lower momentum for heavy produced particles (2 GeV for “free”) (Effects are smaller at high momentum) Open charm mass region (H atom of (single light quark) Well defined nuclear environment (T and  )

Strange Baryons in Nuclear Fields Hypernuclei open a 3 rd dimension (strangeness) in the nuclear chart -- 3 GeV/c K+K Trigger _  secondary target p Double-hypernuclei: very little data Baryon-baryon interactions:  -N only short ranged (no 1  exchange due to isospin)  impossible in scattering reactions  - (dss) p(uud)   (uds)  (uds)

James Ritman Univ. Giessen Exotic Hadrons

James Ritman Univ. Giessen Glueballs g g g C. Morningstar PRD60, (1999) Self interaction between gluons  Construction of color-neutral hadrons with gluons possible exotic glueballs don‘t mix with mesons (qq) 0 --, 0 +-, 1 -+, 2 +-, 3 -+,...

James Ritman Univ. Giessen Prediction in QCD: Collective gluon excitation (Gluons contribute to quantum numbers) Ground state: J PC = 1 -+ (spin exotic) Charm Hybrids ccg distance between quarks

James Ritman Univ. Giessen Mixing With Mesonic States Width: could be narrow (5-50 MeV) since DD suppressed for some states O +-  DD,D*D*,D s D s (CP-Inv.) (QQg)  (Qq) L=0 +(Qq) L=0 (Dynamic Selection Rule) If DD forbidden, then the preferred decay is (ccg)  (cc) + X, e.g  J/ 

James Ritman Univ. Giessen Partial Wave Analysis Partial wave analysis as important tool Example of 1 -+ pd  X(1 -+ )+  +p, X   Strength ~ qq States ! Signal in production but not in formation is interesting !

James Ritman Univ. Giessen The Experimental Facility

HESR

James Ritman Univ. Giessen HESR: High Energy Storage Ring Beam Momentum GeV/c High Intensity Mode: Luminosity 2x10 32 cm -2 s -1 (2x10 7 Hz)  p/p(st. cooling)~10 -4 High Resolution Mode: Luminosity 2x10 31 cm -2 s -1  p/p(e- cooling)~10 -5

James Ritman Univ. Giessen

Target A fiber/wire target will be needed for D physics, A pellet target is conceived: atoms/cm 2 for D=20-40  m 1 mm

James Ritman Univ. Giessen Micro Vertexing 7.2 mio. barrel pixels 50 x 300 μm 2 mio. forward pixels 100 x 150 μm

Central Tracking Detectors example event: pp    4K MVD: (Si) 5 layers Straw-Tubes: 15 skewed double-layers Mini-Drift-Chambers

James Ritman Univ. Giessen Tracking Resolution J/       K + K -  (J  ) = 35 MeV/c 2  (  ) = 3.8 MeV/c 2 Example reaction: pp  J/  (  s = 4.4 GeV/c 2 ) Single track resolution Invariant mass resolution

James Ritman Univ. Giessen PID with DIRC GEANT4 simulation for HESR:

James Ritman Univ. Giessen Electromagnetic Calorimeter Detector materialPbWO 4 Photo sensorsAvalanche Photo Diodes Crystal size  35 x 35 x 150 mm 3 (i.e. 1.5 x 1.5 R M 2 x 17 X 0 ) Energy resolution 1.54 % /  E[GeV] % Time resolution   130 ps (N.B. with PMT!) Total number of crystals7150

James Ritman Univ. Giessen Staged Construction

James Ritman Univ. Giessen Summary GSI will explore the intensity frontier High luminosity cooled p-bar from 1-15 GeV/c Wide physics program including Charmonium spectroscopy pbar-A reactions Search for glueballs and charm hybrids Panda collaboration forming

James Ritman Univ. Giessen List of participating institutions (incomplete) 40 Institutes (32 Locations) from 9 Countries: Austria - Germany – Italy – Netherlands – Poland – Russia – Sweden – U.K. – U.S.

James Ritman Univ. Giessen Physics with stopped antiprotons September 2003 at GSI