PANDA and Charmonium Prospects at FAIR

1
PANDA and Charmonium Prospects at FAIR

• Klaus Peters, GSI and Ruhr-University Bochum
• Beijing, October 15, 2004

talk given at the 3rd Workshop on Quarkonium
2
Overview

• FAIR Project
• Antiproton Project
• Storage Ring
• Physics at Panda
• Panda Experiment
• Other Experiments
• Where do we stand?

3
Facility for Antiproton and Ion Research
4
Facility for Antiproton and Ion Research
Hadron Physics
Plasma Physics
Existing GSI Facilities
Condensed Baryonic Matter
Rare Isotope Beams
Atomic Physics

5
Facility for Antiproton and Ion Research
Panda
6
The Antiproton Facility - HESR
7
The Antiproton Facility - HESR

• Antiproton production similar to CERN
• HESR High Energy Storage Ring
• Production rate 107/s
• Pbeam 1.5 - 15 GeV/c
• Nstored 5 x 1010 p
• Gas-Jet/Pellet/Wire Target

• High luminosity mode
• Luminosity 2 x 1032 cm-2s-1
• dp/p 10-4 (stochastic cooling)
• High resolution mode
• dp/p 10-5 (electron cooling)
• Luminosity 1031 cm-2s-1

8
QCD of bound states Approach

• Increase precision
• measure static properties of well known states
• Increase the database of decays
• search for unusual decay modes to gain
  information
• Excite additional modes
• search for gluonic and radial excitations of
  hadrons
• search for gluonic excitation of the strong
  vacuum
• Put the hadrons to the limits
• put the hadrons in vacuum with different baryon
  density

9
Panda Participating Institutes
more than 300 physicists (48 institutes) from 15
countries
U Basel IHEP Beijing U Bochum U Bonn U INFN
Brescia U INFN Catania U Cracow GSI Darmstadt
TU Dresden JINR Dubna (LIT,LPP,VBLHE) 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 I II 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 IMEP Vienna SINS Warsaw U Warsaw
Spokesperson Ulrich Wiedner
10
Panda Physics Overview

• Charmonium spectroscopy
• Charmed hybrids and glueballs
• Interaction of charmed particles with nuclei
• Hypernuclei
• Many further options
• Open charm decays
• Wide angle compton scattering
• Baryon-Antibaryon production
• CP-Violation (?,D)

11
Charmonium Physics

• ee- interactions
• Only 1-- states are formed
• Other states only bysecondary decays moderate
  mass resolution

• pp reactions
• All states directly formed
• very good mass resolution

CBall, Edwards et al. PRL 48 (1982) 70 E835,
Ambrogiani et al., PRD 62 (2000) 052002
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Resonance Scan
Resonance Cross Section
Measured Rate
Beam Profile
small and well controlled beam momentum spread
Dp/p is extremely important
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Proton-Antiproton Annihilation
Formation
only selected JPC
Production
all JPC available
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Proton-Antiproton Annihilation
only selected JPC
Production
all JPC available

• Gluon rich process creates gluonic excitation
  directly
• cc requires the quarks to annihilate (no
  rearrangement)
• yield comparable to charmonium production
• even at low momenta large exotic content has been
  proven

15
Charmonium Physics with pp

• Expect 1-2 fb-1 (like CLEO-C)
• pp (gt5.5 GeV/c) J/? 107/d
• pp (gt5.5 GeV/c) ?c2 ( J/??) 105/d
• pp (gt5.5 GeV/c) ?c( ff) 104/drec.?
• Comparison of PANDA_at_HESR to E835
• 15 GeV/c maximum mom. instead of 9 GeV/c
• 10x higher Luminosity than achieved before
• charged tracks detector with magnetic field
• 10x smaller dp/p
• stable conditions dedicated high energy storage
  ring

16
Charmed Hybrids

• LQCD
• gluonic excitations of the quark-antiquark-potent
  ial may lead to bound states
• S-potential
• for one-gluon exchange
• P-potential
• from excited gluon flux
• mHcc 4.2-4.5 GeV/c2
• Light charmed hybridscould be narrow if open
  charm decays are inaccessible or suppressed

V(R)/GeV
Hcc
4
DD
3.5
3
R/r0
2
1
important ltr2gt and rBreakup
17
LQCD ccg 1- vs. cc 1-- (J/?)
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Charmed Hybrid Level Scheme

• 1-- (0,1,2)- lt 1 (0,1,2)-
• JKM, NPB 83suppl(2000)304 and Manke,
  PRD57(1998)3829
• L-Splitting
• ?m 100-250 MeV/c2 for 1- to 0-
• S-Splitting
• Page thesis,1995 and PRD 35(1987)1668
• 4.14 (0-) to 4.52 GeV/c2 (2-)
• consistent w/LQCD
• JKM, NPB 86suppl(2000)397, PLB478(2000) 151

DD
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Accessible Charmed Hadrons at PANDA _at_ GSI
p Momentum GeV/c
0
2
4
6
8
12
15
10
?? SS ??
?c?c ScSc ?c?c
OcOc
OO
DD
Two body thresholds
DsDs
Molecules
Gluonic Excitations
Hybrids
HybridsRecoil
exotic charmonium
ggg,gg
Glueball
ggg
GlueballRecoil
qq Mesons
conventional charmonium

• Other exotics with identical decay channels
  same region

Mass GeV/c2
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Heavy Glueballs

• Light gg/ggg-systems are complicated to identify
  (mixing!)
• Exotic heavy glueballs
• m(0-) 4140(50)(200) MeV
• m(2-) 4740(70)(230) MeV
• Width unknown, but!
• nature invests more likely in mass than in
  momentum
• newest proof double cc yield in ee-
• Flavour-blindness
• predicts decays into charmed final states too
• Same run period as hybrids
• In addition scan mgt2 GeV/c2

0- 2-
Morningstar,Peardon, PRD60(1999)34509 Morningstar,
Peardon, PRD56(1997)4043
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Recent open charm discoveries

• The DS Spectrum
• csgt c.c. was not expected to reveal any
  surprises
• Potential model
• Old measurements
• New observations

m GeV/c2
Ds1
DK
Ds2
DsJ (2458)
D0K
DsJ (2317)
Ds
Ds
JP
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DsJ Pairproduction in pp Annihilation
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DsJ Pairproduction in pp Annihilation
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Charmed Hadrons in Nuclear Matter
Partial restoration of chiral symmetry in nuclear
matter Light quarks are sensitive to quark
condensate Evidence for mass changes of pions
and kaons has been deduced previously deeply
bound pionic atoms (anti-)kaon yield and phase
space distribution D-Mesons are the QCD
analogue of the H-atom. chiral symmetry to be
studied on a single light quark
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Charmonium in the Nuclei
GeV/c2 Mass

• Lowering of the DD- mass
• allow charmonium states to decay into this
  channel,
• thus resulting in a dramatic increase of width
• ?(1D) G2040 MeV
• ?(2S) G0,322,7 MeV
• Experiment
• Dilepton-Channels and/or highly constrained
  hadronic channels
• Idea
• Study relative changes ofyield and width of the
  charmonium states

y(33S1)
4
y(13D1)
3.8
y(23S1)
3.6
cc2(13P2)
cc1(13P1)
3.4
cc1(13P0)
3.2
y(13S1)
hc(11S0)
3
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Charmonium mass shift in nuclear matter

• 1 Peskin, NPB 156(1979)365, Luke et al., PLB
  288(1992)355
• 2 Lee, nucl-th/0310080
• 3 Brodsky et al, PRL 64(1990)1011
• 4 Klingel, Kim, Lee, Morath, Weise, PRL
  82(1999)3396
• 5 Lee, Ko PRC 67(2003)038202

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Proposed Detector (Overview)

• High Rates
• Total s 55 mb
• peak gt 107 int/s
• Vertexing
• (sp,KS,?,)
• Charged particle ID
• (e,µ,p,p,)
• Magnetic tracking
• Elm. Calorimetry
• (?,p0,?)
• Forward capabilities
• (leading particles)
• Sophisticated Trigger(s)

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LoI Analysis 1 ?c??

• Main background
• p0p0 and p0?
• with strong forward peaks
• only cos ??0.2, like E760 did
• Analysis
• missing masslt0.16 GeV2
• cos ???lt-0.9999
• Efficiency 10.3 (full kinematical region)
• Main Requirement
• very low energy threshold for backward EMC

Signal
Background
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LoI Analysis 2 ?(3770)DD-

• Peak cross section
• assume 5 nb
• Analysis
• two displaced vertices
• mass difference technique
• helicity angle cut
• 20 efficiency
• To be done
• Kalman filter (for improved resolution)
• Particle (Kaon) ID

mm
Signal
Background
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LoI Analysis 3 µµ- from J/? produced in p63Cu

• Signal
• Calculations from A. Sibirtsev at vs4.05 GeV/c2
• Background
• UrQMD events
• Muons come from the decay of light hadrons
• To be done
• more statistics fro the UrQMD background, so
  that the background shape under the J/? is
  clearly visible

J/?
Signal
Background
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PAX Polarized Antiproton Experiment

• Motivation
• The transversity distribution is the last
  leading-twist missing piece of the QCD
  description of the partonic structure of the
  nucleon
• The transversity distribution is directly
  accessible uniquely via the double transverse
  spin asymmetry ATT in the Drell-Yan production of
  lepton pairs ....
• ... and/or via J/? production, which might be two
  orders of magnitude higher
• Main problems
• physics favors large s (gt50 GeV2)
• needs large polarization of beam and target
• beam polarization technique unverified

32
ASSIA A Study of Spin dependent
Interactions with Antiprotons

• Investigate also Drell-Yan
• Proposed with 40 GeV/c beam accelerated by SIS300
• Target
• NH3 10g/cm2
• Luminosity
• up to 1.5x1031cm-2s-1
• as single user
• Detector
• first part of COMPASS

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Recommendations of the FAIR QCD PAC

• Panda
• The PAC accepts the letter and asks the
  proponents to go ahead to a Technical Proposal
• PAX and ASSIA
• The PAC considers the spin physics of extreme
  interest and the building of an antiproton
  polarized beam as a unique possibility for the
  FAIR project,
• but
• does not approve the letters of intent
• asking
• for a more detailed study of achievable
  antiproton polarization and the anticipated
  physics results.

34
FAIR Structure
AFI Administrative and Financial Issues
ISC International Steering Committee
STI Scientific and Technical Issues
35
FAIR Phases
AFI
Contract Development
Contract Negotiations
Closing
2004
2005
2006
STI
LoI
Proposals/TR s
TDR s
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Road Map towards completion assuming proper
funding

• 2004 (Jan. 15th, April 15th) Letters of Intent
  of experiments and evaluations
• ASSIA, CBM, FLAIR,PANDA, PAX, DIRAC2, Laser
  Cool
• 2005, January 15th Technical Proposals of all
  projects (TP) with Milestones (Accelerators,
  Experiments, ..) followed by Evaluations and
  Green Light for Construction
• 2005, May Project construction starts
  (dominantly Civil Construction)
• 2005-2008 Technical Design Reports (TDR)
  (according to Milestones TPs)
• 2006 High Intensity Running at SIS18
• 2007 LHC is running, laboratories have free
  valences
• for construction of accelerators and detectors
• 2009 SIS100 Tunnel ready for Installation
• 2010 SIS100 Commissioning followed by Physics
• 2011-2013 Step-by-Step Commissioning of the full
  Facility

37
Summary and Outlook

• Its an amazing time in charm spectroscopy
• many new states but no coherent picture
• Where are gluonic excited charmonia (hybrids)
• spectrum, widths and decay channels
• What are the new DsJ states and the X(3872)
• what are their properties like width and decay
  channels
• Interaction with nuclear matter
• mass shifts, broadening and attenuation
• Only high precision experiments can finallyhelp
  to solve the puzzle like Panda _at_ HESR _at_ GSI