PANDA Anti Proton Annihilations at Darmstadt PANDA Experiment

PANDA Anti. Proton Annihilations at Darmstadt • • PANDA Experiment Physics and Data Analysis – – Charmonium, glueballs, hybrids Electromagnetic processes Fritz-Herbert Heinsius – Universität Bochum 23. 10. 2008

PANDA Physics Program • pp- and p. A-annihilation: beam momentum 1. 5 -15 Ge. V/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

Antiprotons at FAIR: PANDA HESR antiprotons 1. 5 -15 Ge. V

Production of particles in pp annihilation Example: glueballs and hybrids • Production in pp collisions • All JPC allowed (including exotic, non q q ) p G H p M p _ _ p p M p H _ M • Formation in pp collisions • All JPC allowed for q q can be generated _ p G _ p s ~ 1 mb p p p s ~ 100 pb H _ p H

Why Antiprotons for Heavy Flavour Spectroscopy? • high resolution spectroscopy with p-beams in formation experiments: Δm given by ΔEbeam (beam cooling) • e+e- interactions: – Only 1 -- states are directly formed – Other states only by secondary decays moderate mass resolution CB E 835 100 c 1 – All charmonium states directly formed – very good mass resolution E 835 ev. /pb pp reactions: CBall ev. /2 Me. V • 1000 3510 3520 Me. V ECM Crystal Ball, Edwards et al. PRL 48 (1982) 70 E 835, Ambrogiani et al. , PRD 62 (2000) 052002

Example: c 1 and c 2 scans at Fermilab E 835 G=0. 88± 0. 05± 0. 03 Me. V Measured rate 1 Resonance cross section G=1. 92± 0. 19± 0. 01 Me. V 2 • • • Crystal Ball: typical resolution ~ 10 Me. V Fermilab: 240 ke. V PANDA: ~30 ke. V Beam M. Andreotti et al. , Nucl. Phys. B 717: 34 -47, 2005.

HESR – High Energy Storage Ring for p Parameters of HESR Injection of p at 3. 7 Ge. V Slow synchrotron (1. 5 -15 Ge. V/c) Storage ring for internal target operation Luminosity up to L~ 2 x 1032 cm-2 s-1 Beam cooling stochastic: dp/p ~ 10 -4 electron up to 8. 9 Ge. V: dp/p < 4. 10 -5 Resonance scan Energy resolution ~50 ke. V Tune ECM to probe resonance Get precise mass and width ECM PANDA

PANDA Targets Parameters of HESR Injection of p at 3. 7 Ge. V Slow synchrotron (1. 5 -15 Ge. V/c) Storage ring for internal target operation Luminosity up to L~ 2 x 1032 cm-2 s-1 Beam cooling stochastic: dp/p ~ 10 -4 electron up to 8. 9 Ge. V: dp/p < 4. 10 -5 PANDA Internal targets • • 4. 1015 H/cm 2 • Pellets • Cluster jet • Nuclei: Be, C, Si, Al

PANDA Collaboration 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 - Detector Target 2. 107 interactions/s 4 p solid angle p 2 T superconducting solenoid + iron return yoke Target Spectrometer 2 Tm dipole magnet ~12 m Forward Spectrometer

PANDA – Vertex Detector vertex reconstruction for decaying particles: < 100 mm Silicon Microvertex Detector

PANDA - Tracking momentum resolution dp/p ~ 1% Silicon Microvertex Detector Central Tracker • Straw tubes • TPC Forward Tracker • GEM • Drift Ch.

PANDA – Particle ID Muon Detectors: MDT charged particle identification e, m, p, K, p, … Forward TOF Barrel DIRC Endcap DIRC Forward RICH

PANDA – Electromagnetic Calorimeter few Me. V to 15 Ge. V Barrel EMC TDR ar. Xiv: 0810. 1216 Forward EMC

Physics – QCD bound states • Charmonium – below threshold: hc – above threshold • X(3872) predictions • Y(4260) simulations • Glueballs and Hybrids – PANDA simulation • D-spectroscopy – Ds 0* production at threshold

Charmonium spectroscopy hep-ph/0211220 c J/Y 2 Y' Y''

Charmonium: Open questions • Below D D threshold – All predicted states detected, but – Lack of precise measurement of mass, width and branching ratios (i. e. hc, hc', hc) • PANDA contributions?

Charmonium below D D threshold: hc • determine spin contribution of confinement potential from PRL 95, 102003 (2005) CLEO m(hc)=(3524. 4± 0. 6± 0. 4) Me. V N=168 ± 40 – precise mass measurement required • two recent measurements – CLEO: e+e-→ (2 S)→hcp 0 hc→ cg c→hadrons – E 835: pp→hc, hc→ cg c→gg • PANDA – scan with high luminosity and precision – detect hadronic decay modes PR D 72, 032001 (2005) E 835 m(hc)=(3525. 8± 0. 2) Me. V 13 events

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. 2 P and 1 D states) – appearance of several new resonances (unclear nature)

Charmonium above D D threshold • (4040), (4160), (4415) – broad structures observed in R=s(e+e-→ hadrons)/s(e+e-→ mm) – lack unambiguous confirmation • 1 D states – only (3770) observed • 2 P states – possibly Y(3940), Z(3990)? • PANDA – perform search for undetected states – establish quantum numbers (high statistics)

New resonances above D D threshold • X(3872) (→J/ p+p-, D 0 p 0, J/ g) JPC=1++ preferred – Belle, Babar, CDFII, D 0 • X(3940) (→ D* D, ≠ D D) JPC=0 -+? – Belle • Y(3940) (→J/ w, ≠ D D) JPC=JP+ – Belle, Babar 9. 4σ • Z(3930) (→D D) JPC=2++ favoured – Belle • Y(4260) (→J/ pp) JPC=1 -– Babar, CLEO, Belle • Y(4350) (→ ' p+p-) JPC=1 -– Babar, Belle • for most states JPC not well established • nature unclear (exotic? ) Phys. Rev. Lett. 91(2003)262001 152 Mill. BB

X(3872) predictions for PANDA pp→X(3872)→ J/y p+p- X(3872) as c 1(2 P) Figures for GX=2. 3 Me. V X(3872) as loosely bound state of D mesons Chen, Ma, PRD 77(2008) 097501

PANDA simulation: Y(4260) J/y→e+e- • Full simulation for various X, Y masses • pp→Y(4260)→ J/y p+p→J/y Y(4260)→ J/y p+p-

Glueballs Detailed predictions of mass spectrum from quenched Lattice. QCD. – Width of ground state 100 Me. V – Several states predicted below 5 Ge. V/c 2, some exotic – Exotic heavy glueballs: • m(0+-) = 4140(50)(200) Me. V • m(2+-) = 4740(70)(230) Me. V Some predicted decay modes: , , J/ . . . Lattice. QCD prediction of glueballs C. Morningstar and M. Peardon, Phys. Rev. D 60, 034509 (1999) 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.

Hybrids • Distinction easier if exotic: 0 --, 0+-, 1 -+, . . . • Search below 2. 2 Ge. V/c 2: e. g. p 1(1600) (E 852, VES, COMPASS) but: high density of mesons q q 1 - Gluon 1+ Gluon 0 -+ 1++ 1 -- 0+- 0 -+ 1+- 1 -+ 2+- 2 -+ exotic

Hybrids • Distinction easier if exotic: 0 --, 0+-, 1 -+, . . . • Search below 2. 2 Ge. V/c 2: e. g. p 1(1600) (E 852, VES, COMPASS) but: high density of mesons • Charmonium region: less populated • ground state • predicted at ~4. 3 Ge. V/c 2 • Exotic: JPC=1 -+ • Could be narrow: 5 -50 Me. V

Charmonium hybrid states �c 1 1++ � 1 -- +h� c 0 0 -+ � c 0 0 +h� c 1 1 -+ � c 1 1 +h� c 2 2 -+ � c 2 2 • charmonium final state • open charm final state

Charmonium hybrid states: simulation • charmonium final state c 1 Efficiency PANDA simulation

Determination of mass and width of Ds. J*(2 xxx) • The width of Ds 0*(2317) can be measured in the reaction pp Ds. Ds 0*(2317) threshold Ds*Ds 0* By making an energy scan around threshold → counting signal events, determine the excitation function and extract the width and mass 29

Production rates (1 -2 fb-1) • low multiplicity events trigger on defined final states

Baryon spectroscopy

Electromagnetic processes • Time like electromagnetic form factors – pp e+e– wide kinematic range – separate measurement of GM and GE • Hard exclusive processes • Drell-Yan – pp e+e-, pp m+m– transverse quark distributions BG suppression for FF (PID and kinematic fit, full simulation) m+m- ≥ 106 p+p- ≥ 108 less than 1% feed through

Summary • Production of mesons, hybrids, glueballs in formation – all q q quantum numbers – resonance scan technique • precise determination of mass and width ~30 ke. V – 2. 25 Ge. V/c² < m < 5. 47/c² Ge. V/c² • Production of baryons, mesons, hybrids, glueballs with recoiling particles – all quantum numbers – antiproton momentum from 1. 5 to 15 Ge. V/c • Charmonium below and above D D threshold • Baryon spectroscopy • Electromagnetic processes