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PANDA AntiProton Annihilations at Darmstadt PANDA Experiment Physics and Data Analysis –Charmonium, glueballs, hybrids –Electromagnetic processes Fritz-Herbert Heinsius – Universität Bochum 23.10.2008
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PANDA Physics Program pp- and p A-annihilation: beam momentum 1.5-15 GeV/c Meson spectroscopy - charmonium states - open charm production - exotic matter -glueballs -hybrids -molecules - light mesons Baryon-Antibaryon production Charm in nuclei Hypernuclei physics Hadrons in nuclear medium Electromagnetic processes
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Antiprotons at FAIR: PANDA HESR PANDA antiprotons 1.5-15 GeV
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Production of particles in pp annihilation Example: glueballs and hybrids Production in pp collisions All J PC allowed (including exotic, non q q ) Formation in pp collisions All J PC allowed for q q can be generated p p _ G M p M H p _ p M H p _ p p _ p p _ H p p _ H G ~ 1 b ~ 100 pb
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Why Antiprotons for Heavy Flavour Spectroscopy? high resolution spectroscopy with p-beams in formation experiments: Δm given by ΔE beam (beam cooling) 35003520 MeV3510 CBall ev./2 MeV 100 E CM e + e - interactions: – Only 1 -- states are directly formed – Other states only by secondary decays moderate mass resolution pp reactions: –All charmonium states directly formed –very good mass resolution CB E835 1000 E 835 ev./pb c1 Crystal Ball, Edwards et al. PRL 48 (1982) 70 E835, Ambrogiani et al., PRD 62 (2000) 052002
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Example: c1 and c2 scans at Fermilab E835 22 Measured rate Beam Resonance cross section Crystal Ball: typical resolution ~ 10 MeV Fermilab: 240 keV PANDA: ~30 keV 11 M. Andreotti et al.,Nucl.Phys.B717:34-47,2005. =0.88 ± 0.05 ± 0.03 MeV =1.92±0.19 ± 0.01 MeV
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E CM HESR – High Energy Storage Ring for p Parameters of HESR Injection of p at 3.7 GeV Slow synchrotron (1.5-15 GeV/c) Storage ring for internal target operation Luminosity up to L~ 2x10 32 cm -2 s -1 Beam cooling stochastic: p/p ~ 10 electron up to 8.9 GeV: p/p < 4. 10 Resonance scan Energy resolution ~50 keV Tune E CM to probe resonance Get precise mass and width
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PANDA Targets Parameters of HESR Injection of p at 3.7 GeV Slow synchrotron (1.5-15 GeV/c) Storage ring for internal target operation Luminosity up to L~ 2x10 32 cm -2 s -1 Beam cooling stochastic: p/p ~ 10 electron up to 8.9 GeV: p/p < 4. 10 Internal targets 4. 10 15 H/cm 2 Pellets Cluster jet Nuclei: Be, C, Si, Al
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At present a group of more than 350 physicists in 15 countries U Basel IHEP Beijing U Bochum U Bonn U & INFN Brescia U & INFN Catania U Cracow GSI Darmstadt TU Dresden JINR Dubna U Edinburgh U Erlangen NWU Evanston U & INFN Ferrara U Frankfurt LNF-INFN Frascati U & INFN Genova U Glasgow U Gießen KVI Groningen U Helsinki IKP Jülich U Katowice IMP Lanzhou U Mainz U & Politecnico & INFN Milano U Minsk TU München U Münster BINP Novosibirsk LAL Orsay U Pavia IHEP Protvino PNPI Gatchina U of Silesia U Stockholm KTH Stockholm U & INFN Torino Politechnico di Torino U Oriente, Torino U & INFN Trieste U Tübingen U & TSL Uppsala U Valencia SMI Vienna SINS Warsaw U Warsaw PANDA Collaboration
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PANDA - Detector ~12 m Target Spectrometer Forward Spectrometer 2T superconducting solenoid + iron return yoke 2Tm dipole magnet Target p 2. 10 7 interactions/s 4 solid angle
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PANDA – Vertex Detector Silicon Microvertex Detector vertex reconstruction for decaying particles: < 100 m
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PANDA - Tracking Silicon Microvertex Detector Central Tracker Straw tubes TPC Forward Tracker GEM Drift Ch. momentum resolution p/p ~ 1%
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PANDA – Particle ID Muon Detectors: MDT Barrel DIRCEndcap DIRCForward RICH Forward TOF charged particle identification e, , , K, p, …
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PANDA – Electromagnetic Calorimeter Barrel EMC Forward EMC few MeV to 15 GeV EMC TDR arXiv:0810.1216
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Physics – QCD bound states Charmonium –below threshold: h c –above threshold X(3872) predictions Y(4260) simulations Glueballs and Hybrids –PANDA simulation D-spectroscopy –D s0 * production at threshold
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Charmonium spectroscopy c J/ 2 ' '' hep-ph/0211220
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Charmonium: Open questions Below D D threshold –All predicted states detected, but –Lack of precise measurement of mass, width and branching ratios (i.e. c, c ', h c ) PANDA contributions?
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Charmonium below D D threshold: h c CLEO 13 events N=168 ± 40 PR D72, 032001 (2005) PRL 95, 102003 (2005) determine spin contribution of confinement potential from –precise mass measurement required two recent measurements –CLEO: e + e - → (2S)→h c 0 h c → c c →hadrons –E835: pp→h c, h c → c c → PANDA –scan with high luminosity and precision –detect hadronic decay modes E835 m(h c )=(3524.4±0.6±0.4) MeV m(h c )=(3525.8±0.2±0.2) MeV
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Charmonium: Open questions Above D D threshold –only 4 vector states detected (not all unambiguously confirmed) –diagnostic of long range spin dependant qq potential (e.g. 2P and 1D states) –appearance of several new resonances (unclear nature)
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Charmonium above D D threshold (4040), (4160), (4415) –broad structures observed in R= (e + e - → hadrons)/ (e + e - → ) –lack unambiguous confirmation 1D states –only (3770) observed 2P states –possibly Y(3940), Z(3990)? PANDA –perform search for undetected states –establish quantum numbers (high statistics)
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New resonances above D D threshold X(3872) (→J/ D 0 D 0 , J/ ) J PC =1 ++ preferred –Belle, Babar, CDFII, D0 X(3940) (→ D * D,≠ D D) J PC =0 -+ ? –Belle Y(3940) (→J/ ≠ D D) J PC =J P+ –Belle, Babar Z(3930) (→D D) J PC =2 ++ favoured –Belle Y(4260) (→J/ ) J PC =1 -- –Babar, CLEO, Belle Y(4350) (→ ' ) J PC =1 -- –Babar, Belle for most states J PC not well established nature unclear (exotic?) 9.4σ Phys. Rev. Lett. 91(2003)262001 152 Mill. BB
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X(3872) predictions for PANDA Chen, Ma, PRD77(2008) 097501 X(3872) as c1 (2P) X(3872) as loosely bound state of D mesons pp→X(3872)→ J/ + - Figures for X =2.3 MeV
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PANDA simulation: Y(4260) J/ →e + e - Y(4260)→ J/ + - Y(4260)→J/ Full simulation for various X,Y masses pp→Y(4260)→ J/ + - →J/
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Glueballs Detailed predictions of mass spectrum from quenched LatticeQCD. –Width of ground state 100 MeV –Several states predicted below 5 GeV/c 2, some exotic –Exotic heavy glueballs: m(0 +- ) = 4140(50)(200) MeV m(2 +- ) = 4740(70)(230) MeV Some predicted decay modes: , , J/ , J/ ... The detection of non-exotic glueballs is not trivial, as these states mix with the nearby q q states with the same quantum numbers, thus modifying the expected decay pattern. C. Morningstar and M. Peardon, Phys. Rev. D 60, 034509 (1999) LatticeQCD prediction of glueballs
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Hybrids Distinction easier if exotic: 0 --, 0 +-, 1 -+,... Search below 2.2 GeV/c 2 : e.g. 1 (1600) (E852, VES, COMPASS) but: high density of mesons qqqq 1 - Gluon1 + Gluon 0 -+ 1 ++ 1 -- 0 +- 0 -+ 1 +- 1 -+ 2 +- 2 -+ exotic
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Hybrids Distinction easier if exotic: 0 --, 0 +-, 1 -+,... Search below 2.2 GeV/c 2 : e.g. 1 (1600) (E852, VES, COMPASS) but: high density of mesons Charmonium region: less populated ground state predicted at ~4.3 GeV/c 2 Exotic: J PC =1 -+ Could be narrow: 5-50 MeV
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Charmonium hybrid states charmonium final state open charm final state c1 ++ 1 -- h c0 0 +- c0 0 -+ h c1 1 +- c1 1 -+ h c2 2 +- c2 2 -+
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Charmonium hybrid states: simulation charmonium final state c1 PANDA simulation Efficiency
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By making an energy scan around threshold → counting signal events, determine the excitation function and extract the width and mass threshold D s *D s0 * The width of D s0 *(2317) can be measured in the reaction pp D s D s0 *(2317) 29 Determination of mass and width of D sJ *(2xxx)
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Production rates (1-2 fb -1 ) low multiplicity events trigger on defined final states
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Baryon spectroscopy
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Electromagnetic processes Time like electromagnetic form factors – pp e + e - –wide kinematic range –separate measurement of G M and G E Hard exclusive processes Drell-Yan – pp e + e -, pp + - –transverse quark distributions BG suppression for FF (PID and kinematic fit, full simulation) + - ≥ 10 6 + - ≥ 10 8 less than 1% feed through
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Summary Production of mesons, hybrids, glueballs in formation –all q q quantum numbers –resonance scan technique precise determination of mass and width ~30 keV –2.25 GeV/c² < m < 5.47/c² GeV/c² Production of baryons, mesons, hybrids, glueballs with recoiling particles –all quantum numbers –antiproton momentum from 1.5 to 15 GeV/c Charmonium below and above D D threshold Baryon spectroscopy Electromagnetic processes
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