New Opportunities for Hadron Physics with the Planned PANDA Detector Overview of the PANDA Physics Program The PANDA Detector Selected Simulation Results Charmonium: EM decays Charmonium: Open charm decays Charmonium in nuclear matter James Ritman Univ. Giessen

James Ritman Univ. Giessen What Do We Want To Know? Why don‘t we observe isolated quarks? Q-Q potential in the charmonium 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 Mass [MeV] Binding energy [meV] 4100 y ¢¢¢ (4040) Ionisationsenergie 3 P (~ 3940) 2 3900 D 3 1 S 3 3 (~ 3800) 3 S 3 1 D 3 3 D 3 P (~ 3880) 1 2 1 3 -1000 2 3 3 D 1 3 P (~ 3800) y ¢¢ (3770) 1 D 2 3 P 2 3 D 2 1 S 2 3 S 2 1 P 2 3 3 D 3 D 2 2 1 1 2 3 P 1 1 ~ 600 meV 3700 y ¢ (3686) Threshold 2 3 P 10-4 eV -3000 h ¢ c (3590) c (3556) h (3525) 2 c c (3510) 3500 1 c (3415) -5000 Charmonium ähnlicher Stellenwert wie Positronium bzw. Wasserstoffatom einfach (nicht-relativistisch) am besten verstanden 3300 1 3 S 1 1 S 1 8·10-4 eV -7000 y (3097) 3100 e + 0.1 nm e - h c (2980) C 1 fm C 2900 James Ritman Univ. Giessen

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

James Ritman Univ. Giessen High Resolution Crystal Ball: typical resolution ~ 10 MeV Fermilab: 240 keV  p/p < 10-4 needed James Ritman Univ. Giessen

James Ritman Univ. Giessen Open Questions c (11S0) (Simu results) experimental error on M > 1 MeV G hard to understand in simple quark models c’ (21S0) Crystal Ball result way off study of hadronic decays hc(1P1) Spin dependence of QQ potential Compare to triplet P-States LQCD  NRQCD James Ritman Univ. Giessen

James Ritman Univ. Giessen Open Questions States above the DD threshold Higher vector states not confirmed Y(3S), Y(4S) Expected location of 1st radial excitation of P wave states Expected location of narrow D wave states Only Y(3770) seen Sensitive to long range Spin- dependent potential (Simu results) James Ritman Univ. Giessen

Why Are Hadrons So Heavy? James Ritman Univ. Giessen

Hadron Masses 2Mu + Md ~ 15 MeV/c2 Protons = (uud) ? Mp = 938 MeV/c2 no low mass hadrons (except p, K, h) spontaneously broken chiral symmetry (P.Kienle)

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

J/Y Absorption in Nuclei J/Y absorption cross section in nuclear matter p + A  J/Y + (A-1) (Simu results)

Comparison of p-A Reactions to A-A Much lower momentum for heavy produced particles (2 GeV for “free”) (Effects are smaller at high momentum) Well defined nuclear environment (T and r) James Ritman Univ. Giessen

The Experimental Facility James Ritman Univ. Giessen

HESR

HESR: High Energy Storage Ring Beam Momentum 1.5 - 15 GeV/c High Intensity Mode: Luminosity 2x1032 cm-2s-1 (2x107Hz) dp/p (st. cooling) ~10-4 High Resolution Mode: Luminosity 2x1031 cm-2s-1 dp/p (e- cooling) ~10-5 James Ritman Univ. Giessen

James Ritman Univ. Giessen

James Ritman Univ. Giessen

Central Tracking Detectors MVD: (Si) 5 layers ~ 9 Mio pixels Andrei Sokolov HK39.5 Thursday 15:00 Straw-Tubes Mini-Drift-Chambers

James Ritman Univ. Giessen PID ToF Muon Detectors DIRC (DIRC@BaBar) James Ritman Univ. Giessen

James Ritman Univ. Giessen Open Charm pp DD DKpp „no background events added“ Mass Resolution ~ 10 MeV/c2 James Ritman Univ. Giessen

Vertex Distributions GEANT4 Transverse D meson signal DPM background signal DPM background Scale up by x10! 0.15 < Vz < 5 mm Longitudinal James Ritman Univ. Giessen

James Ritman Univ. Giessen DD Missing Mass signal DPM background N.B. different x scale | Mmiss 2|< 0.001 GeV2 (tight cut) James Ritman Univ. Giessen

James Ritman Univ. Giessen Open Charm As an example of the Pbar P  Y(3770)  DD Analysis Plot MDD – MD – MD + 2x1869MeV raw S/B ~ 10-7 James Ritman Univ. Giessen

Detection of Rare Neutral Channels As an example: hcgg Background: p0g, p0p0 hc:p0g:p0p0 1:50:500 Comparison with E835 (PLB 566,45) PANDA James Ritman Univ. Giessen

Dimuon Spectrum in p+Cu Beam momentum “on resonance” Full background simulations (result scaled up) Muons from J/Y have high Pt J/Y has low Pt (coplanar) J/Y James Ritman Univ. Giessen

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

James Ritman Univ. Giessen

James Ritman Univ. Giessen In part supported by: GSI BMBF 06GI144 DFG James Ritman Univ. Giessen

James Ritman Univ. Giessen Target A fiber/wire target will be needed for D physics, A pellet target is conceived: 1016 atoms/cm2 for D=20-40 mm 1 mm James Ritman Univ. Giessen

Electromagnetic Calorimeter Detector material PbWO4 Photo sensors Avalanche Photo Diodes Crystal size  35 x 35 x 150 mm3 (i.e. 1.5 x 1.5 RM2 x 17 X0) Energy resolution 1.54 % / E[GeV] + 0.3 % Time resolution s  130 ps (N.B. with PMT!) Total number of crystals 7150 James Ritman Univ. Giessen

James Ritman Univ. Giessen Tracking Resolution Single track resolution Invariant mass resolution Example reaction: pp  J/y + F (s = 4.4 GeV/c2) J/y  m+m- F  K+K- s(J/y) = 35 MeV/c2 s(F) = 3.8 MeV/c2 James Ritman Univ. Giessen

James Ritman Univ. Giessen Staged Construction James Ritman Univ. Giessen

Pbar-Nucleus Interactions The interaction of charmed mesons with the baryonic environment strongly effects production rates near threshold James Ritman Univ. Giessen

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

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

James Ritman Univ. Giessen The GSI Future Project Nuclear Structure: paths of nucleo-synthesis Heavy Ion Physics: hot and dense nuclear matter 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

James Ritman Univ. Giessen Open Questions The c(11S0) The c(21S0) The hc(1P1) States above the DD threshold James Ritman Univ. Giessen

Proton Form Factors at large Q2 At high values of momentum transfer |Q2| the system should be describable by perturbative QCD. Due to dimensional scaling, the FF should vary as Q4. The time like FF remains about a factor 2 above the space like. These differences should vanish in pQCD, thus the asymptotic behavior has not yet been reached at these large values of |q2|. (HESR up to s ~ 25 GeV2) q2>0 q2<0 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*,DsDs (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. 1-+  c + h James Ritman Univ. Giessen

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

James Ritman Univ. Giessen Exotic Hadrons James Ritman Univ. Giessen

James Ritman Univ. Giessen Glueballs C. Morningstar PRD60, 034509 (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-+,... g 1GeV=32pt James Ritman Univ. Giessen

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

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

James Ritman Univ. Giessen Quark Condensate The QCD vacuum is not empty Hadron masses are generated by the strong interaction with <qq> (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. James Ritman Univ. Giessen

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

Deeply Bound Pionic Atoms Pionic capture is possible with the appropriate choice of kinematics: d+n  3He + p- These results indicate a mass shift of ~25 MeV for pions at normal nuclear matter density. James Ritman Univ. Giessen

Kaons in Nuclear Matter Kaon and anti-kaon masses should no longer be degenerate in nuclear matter. Expected signal: increased K- production compared to K+. J.Schaffner-Bielich et al., Nucl. Phys. A (1997) 325. James Ritman Univ. Giessen

Measured K- Cross Section Comparison of proton-proton data with heavy ion data[2]: dramatic enhancement of the K- production probability KaoS [1] A.Sibirtsev et al., Z.Phys. A358 (1997) 101. [2] F.Laue et al., Phys.Rev. Lett. 82 (1999) 1640. [3] C.Quentmeier et al., Phys Lett B 515 (2001) 276. James Ritman Univ. Giessen

James Ritman Univ. Giessen Open Charm in Nuclei The interaction of charmed mesons with the baryonic environment strongly effects production rates near threshold James Ritman Univ. Giessen

cc Production in Nuclear Matter The mass of charmonium states is not expected to change much. However, a drop of the DD mass leads to a widening of the cc states. Y’ will have too high momentum, most decay outside.  but wider tails James Ritman Univ. Giessen

James Ritman Univ. Giessen Charmonium in Nuclei Due to the increased width, the dileptons from charmonium states below the free DD threshold are strongly suppressed. Golubeva et al. Eur.Phys.J. A17 (2003) 275-284 James Ritman Univ. Giessen