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PANDA @ FAIR activities of IPN Orsay

PANDA @ FAIR activities of IPN Orsay. GDR, Orsay, October 3rd, 2011. outline. Motivations Feasibility studies for proton Time-Like electromagnetic Form Factors measurements Related works: phenomenology, simulation and event reconstruction issues. Conclusions.

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PANDA @ FAIR activities of IPN Orsay

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  1. PANDA @ FAIR activities of IPN Orsay GDR, Orsay, October 3rd, 2011 Orsay, GDR

  2. outline • Motivations • Feasibility studies for proton Time-Like electromagnetic Form Factors measurements • Related works: phenomenology, simulation and event reconstruction issues. • Conclusions Orsay, GDR

  3. A new facility in Europe with high quality antiproton beams HADES High Energy Storage Ring for antiprotons 1.5 – 15 GeV/c L = 2 x 1032 cm-2 s-1 σp/p = 10-4 2x107 int.s-1 PANDA • Hadron Structure and Dynamics • Nuclear and Quark Matter • Physics and Chemistry of SuperHeavy Elements • Nuclear Structure and Astrophysics • Atomic, Plasma and Materials Physics • Radiobiology Orsay, GDR

  4. Forward Spectrometer Target Spectrometer A multipurpose 4 detector : PANDA IPN ORSAY R&D contribution 20000 crystals of PbWO4 at -25°C • Detector requirements: • nearly 4π solid angle • high rate capability: 2x107 interactions/s; • good momentum resolution Δp/p ≈ 1%; • vertex resolution < 100 μm • for K0, Σ, Λ, (D± ,cτ ≈ 317 μm); • good PID (γ, e, μ, π, Κ, p); • γ detection, few MeV < Eγ < 10 GeV. Orsay, GDR

  5. The PANDA Collaboration At present a group of 420 physicists from 53 institutions of 16 countries Austria – Belaruz - China - France - Germany –India - Italy – Netherlands Poland – Romania - Russia – Spain - Sweden – Switzerland - U.K. – U.S.A.. Basel, Beijing, Bochum, IIT Bombay, Bonn, Brescia, IFIN Bucharest, Catania, Chicago, Cracow, IFJ PAN Cracow, Cracow UT,Dresden, Edinburg, Erlangen, Ferrara, Frankfurt, Genova, Giessen, Glasgow, GSI, FZ Jülich, JINR Dubna, Katowice, KVI Groningen, Lanzhou, LNF, Lund, Mainz, Minsk, ITEP Moscow, MPEI Moscow, TU München, Münster, Northwestern, BINP Novosibirsk, IPN Orsay, Pavia, PiemonteOrientale, IHEP Protvino, PNPI St. Petersburg, KTH Stockholm, Stockholm, U Torino, INFN Torino, Torino Politecnico, Trieste, TSL Uppsala, Tübingen, Uppsala, Valencia, SINS Warsaw, TU Warsaw, SMI Wien Orsay, GDR http://www.gsi.de/panda

  6. antiProton ANnilation at DArmstadt S=2 Hypernuclei Search for Exotics (glueballs, hybrids) Charm in Medium Study of the strong force using anti-protons Charmonium Spectroscopy Nucleon Structure ... and more .... Orsay, GDR

  7. The actors of the french project Joint project of experimentalists and phenomenologists previously or still involved in experiments at JLab, Mainz, GSI: T. Hennino, R. Kunne, D. Marchand, S. Ong, B. R., J. Van de Wiele (IPNO). F. Maas (IPNO 2005-2007) E. Tomasi-Gustafsson (CEA/IRFU and IPNO >2009), H. Fonvieille (LPC-Clermont-Ferrand). E. Becheva (post-doc 2005-2006), J. Boucher (PhD 2008-2011), A. Dbeyssi (PhD 2010-2013), T. Liu (post-doc 2011), M. Sudol (post-doc 2008-2012) B. Ma (PhD 2011-2014) Technical staff(IPNO R&D detector and computing departments) C. Diarra (IPNGrid), I. Hrivnacova (computing), M. Imre, C. Le Galliard, A. Maroni, P. Nguyen (IPNGrid) , J. Peyré, J. Pouthas, P. Rosier, L. Seminor, C. Théneau, T. Zerguerras Orsay, GDR

  8. What do we want to measure ? Orsay, GDR

  9. e- e+ - p e+ p p p Nucleon form factors The nucleon internal structure is characterized by two form-factors : Form factors can be directly compared to nucleon structure models  powerful tools for understanding non perturbative QCD  A.Drago’s talk Lattice calculations J. Carbonell’s talk They provide constraints for GPD ElectricGE(Q2)=F1(Q2)-F2(Q2) MagneticGM(Q2)=F1(Q2)+F2(Q2) Time-Like q2>0 Space-like * -Q2=q2 < 0 GM(0) = p GE(0) = 1 * e- Form factors are complex for q2 > 4m2 Form factors are real Orsay, GDR

  10. GMp ? -12 -8 -4 0 4 8 q2(GeV/c)2 SL TL Proton form factor measurements are needed… From low to high energies, in Time-like and Space-Like regions Dispersion relation prediction Drechsel et al nucl-th/9712013 Vector Dominance Model Low q2 S. Pacetti’s talk High q2 asymptotic behaviour: Phragmèn-Lindelöf theorem Phase of Time-Like FF vanishes Perturbative QCD Quark counting rules Helicity conservation GM (q2)~ q - 4 GE (q2) ~ q - 4 Orsay, GDR

  11. GEp (I) GEp (II) GEp (IIII) proton electromagnetic form factors in Space-Like region • Rosenbluth method: (diff. cross sections) GE(q2) ~ GM(q2) ~ GD(q2) = 1/(1+q2/md2) 2 md=0.71 (GeV/c2) Rosenbluth method Perdrisat et al., progress in part. and Nucl. Physics 59 (2007) 694 Puckett et al. Nucl. ArXiV: [nucl-exp]1102:5735 Puckett et al, PRL104 (2010) 242301 Recoil proton polarization measurements • Contradictory results for GE/GM (2  contribution, radiative corrections ?) • Deviation of GE from dipole, pQCD not reached • Zero-crossing of GE(Q2) • Projects at JLab12 GeV • GpE/GpMup to 14.5 (GeV/c)2 • GpM up to 18 (GeV/c)2 Orsay, GDR

  12. proton electromagnetic form factors in Time-Like region - Cross-sections: pp  e+e- - - 4mp2 - angular distributions: pp  e+e- FENICE+DM2 (e+e-) Geff BABAR: (e+e-pp) - (pp) E835 LEAR (pp) • Geff : large error bars above 13 (GeV/c)2 • |GE/GM|: • Inconsistent data above threshold • Lack of precise data above 5 (GeV/c)2 - Orsay, GDR

  13. Goal of PANDA measurements Extract Time-Like |GE| and |GM| for proton up to 14 (GeV/c)2 from lepton angular distributions in pp e+e- reaction and measure Geff up to 30 (GeV/c)2 - • Two major challenges: • Decrease of sensitivity to GE with increasing q2 • Huge hadronic background •  (pp +-) /  (pp e+e-) ~106 Full scale GEANT4 simulations « BABAR » framework CCIN2P3 & IPNO - - • Background suppression factor is at • least of the order of 109 • Taking into account PID & kinematic fit • contamination <<1% Orsay, GDR

  14. _ Rejection of pp  +- Straw Tube Tracker ElectroMagneticCalorimeter DIRC(Cerenkov) • Use complementarity of e/ discrimination capability of the different detectors • validity of the simulations ? • « local » simulations, • results of previous detectors • dE/dx calculations • hadronic GEANT4 physics models •  Bertini Cascade ( - , °) , ° 2 Edep/p ~ 1 EMC response to - p=1.5 GeV/c Sensitivity to hadronic models T. Zerguerras Orsay, GDR

  15. -VDM: F. Iachello et al., PLB43, 171 (1973) …extended VDM, PRC66, 045501 (2002) Egle Tomasi-Gustafsson et al., EPJA24 (2005) 419 Courtesy of S. Pacetti E. Tomasi-Gustafsson and M.P. Rekalo, PLB504,291 E. Tomasi-Gustafsson, arXIv:0907.4442 Geff PANDA PANDA < 1% ~10% ~23% ~50% PANDA will bring Precise determination of |GE|and |GM |up to 14 (GeV/c)2 Geff up to 30 (GeV/c)2: transition towards perturbative QCD Phragmèn-Lindelöf theorem ? Time-Like Form Factor measurement with PANDA : precision estimates L=2 fb-1 Sudol et al. EPJA 44 (2010) 373 PANDA BES) BES) pQCD ? Orsay, GDR

  16. Low quality data No data Precise data Unphysical region p p → e+ e- π0 - Space Like (SL) pp  e+e- annihilation | Time Like (TL) γ(q) q2 < 0 e+ p q2 = s q2 > 4mp2 Гμ(q) p p p e- FFs real FFs complex q2 4mp2 Time-Like form factors in the unphysical region Dispersion relations • Vector meson poles: q2 = m2, m2, m2 • Vector Meson Dominance (VMD) form factor models can be tested Orsay, GDR

  17. Time-Like form factors in the unphysical region - p e+ q2 e- p + exch. ° Basic idea: reach q2 < 4 mp2 by giving 4-momentum to another particle (e.g. π0) M. P. Rekalo, Sov. J. Nucl. Phys., vol1, 760 (1965) • 1st calculation of d/dq2 for • C. Adamuščín et al., Phys. Rev. C 75, 045205, 2007 •  Very large cross-sections Orsay, GDR

  18. p p → 0 p p → 0 | | - pp  e+e- 0 - p e+ q2 e- p + exch. ° p p → e+ e- π0 | Form factors in the unphysical region (II) New investigations by J. Van de Wiele and J. Boucher • d5 / dq2d0d0 d ede • constrained on existing data for (Fermilab) J. Boucher’s PhD GE and GM from Iachello et al. Orsay, GDR

  19. - pp  e+e- 0 Feasibilitystudy for • Resolution q2~ 10-20 (MeV/c2)2 (T.Liu) • Efficiency: 0.2-0.45 (G. Gumberidze) • Hadronic tensor and form factor extraction (J. Boucher) • Background: For fixed θπ0 and q², Fit of lepton angular distributions in * frame  hadronic tensors  R=|GE/GM| and cos(E-M) R=0.02-0.03 Jerôme Boucher’s talk Also useful for TDA extraction - Fitted on LEAR data pp  +- 0 3 production mechanisms: non-resonant, ρ and f2  d5 J. Boucher’s PhD Rejection using PID and kinematics Orsay, GDR  +  - inv. mass

  20. - pp  e+e- 2 contributions and radiative corrections Rosenbluth method Important role of 2 exchange and radiative corrections • Phenomenological work for : • radiative corrections:Ahmadov et al., Phys.Rev.D82:094016,2010 • 2 exchange : G. Gakh and E. Tomasi-Gustafsson NPA761 (2005)120.  odd cos  termsd/dcose ~ A (1+ b cosesin2 e + c cos2e+..) b=0 in 1 exchange • PANDA measurements are sensitive to b=5% (M. Sudol et al EPJA 44(2010) 373). Polarization measurements ? Orsay, GDR

  21. Event generators with radiative corrections | p p → e+ e- p p → e+ e- ° | p p → e+ e- p p → e+ e- π0 | | • studies of the PHOTOS package (A.Dbeyssi, M. Gumberidze, E. Tomasi-Gustafsson) • Calculation for and including vacuum polarization (J. Van de Wiele and S. Ong) • comparison with Photos • Effects of proton radiation • Egle Tomasi-Gustafsson: PRD82:094016,2010 PRC83:025202,2011 Orsay, GDR

  22. | p p Parametrizationof cross-sections - Total,elastic pion production NN+pions A. Dbeyssi et al. PANDA Note 2011 Applications: background estimates, trigger design Orsay, GDR

  23. Filter studies for e+e- or e+e-0 exit channels Example: pinc=4 GeV/c<n>~6 σ(pp→6)~10 mb suppression of +-4° - +-4° w/o cut +-4° Fast selection based on EMC info: Emax>2.4 GeV and Etot > 4 GeV (R. Kunne and T. Hennino) Orsay, GDR

  24. Other possible measurements with PANDA - - - • More about electromagnetic Time-Like proton form factors • pp  +- (collaboration with Torino) • pd  n e+e- H. FonvieilleEPJA42 (2009)287 • Polarization in pp  e+e- relative phase of GE and GM • Electromagnetic processes: • pp  , pp  ° (Giessen) • pp  e+e-° (Transition Distribution Amplitude p) (Mainz+ B. Ma at IPN Orsay) J.P. Lansberg • pp  +- X(Torino, Ferrara) • pQCD mechanisms: • pp  +  - , K+ K- S.Ong and J. Van de Wiele • color transparency : e.g.  (pA(A -1) +-) / (pp +-) B. Pire • Others (phenomenological work E. Tomasi-Gustafsson et al.): • vacuum excitations: (pp  K+ K-) /(pp  +  - ) PRD81 (2010) 017501 • Deviation from Rutherford formula: pA/pA elastic scattering PRC80 (2009) 018201 • Polarization observables in ep scattering (A. Dbeyssi’s talk ) - - - K. Semenov’s talk - - - - - - - - Orsay, GDR

  25. Hadronic channels - pp  K+K- , - - - - - - pp  e+e- pp  +- , pp  +- 0 pp  +- , pp  e+e-0 pp  +- 0 understand the reaction mechanism and the transition towards pQCD • only low quality data exist from CERN • High statistics expected at PANDA, easy to measure • needed anyway to control the background for proton form factor measurements in and reactions • theoretical work: J. Van de Wiele and S. Ong EPJA46 (2010) 291: models checked on existing data to be used as generators for simulations Possibility to explore up to -t=30 (GeV/c)2 With PANDA Orsay, GDR

  26. See M. Gumberidze’s talk • EMC PDF for Bayesian PID method • ° reconstruction and to be started … • muon reconstruction (M. Gumberidze) • electron tracking (studies with Kalman Filter) • dE/dx R. Kunne B. Ma Orsay, GDR simulation/reconstruction code development for PANDAroot

  27. Contribution to PANDAGRID PANDAGRID node at IPNO D. Marchand Orsay, GDR

  28. 1 slice= 1/16 barrel = 720 crystals = 720 kg Technical Contribution IPNO (technical division) • Barrel calorimeter: 11000 PbWO4 crystals • Mechanical structure: carbonalveoles + Al inserts • Proto60 • 60 crystalscooled to -25° • tests withBremsstrahlung photons at MAMI J. Pouthas, J. Peyré, C. Le Galliard, P. Rosier, T. Zerguerras, M. Imre, A. Maroni, C. Théneau sE/E = 1.8% / √E + 0.65% J.Boucher PhD light transmission Test of different glues Electronic benchtest (A. Dbeyssi, E.Tomasi-Gustafsson, D. Marchand)

  29. Conclusion and outlook: simulation / analysis activities of the French team Time-LikeForm-factors feasibilitystudies in pp  e+e- andpp  e+e-° relatedphenomenologicalworks Developments for simulation software (Pandaroot) Further future: feasibilitystudieswith up-dated full scale simulations: pp  e+e- (formfactors, collaboration with Mainz) pp  +- (collaboration with Torino) pp  e+e-° (formfactors and Transition Distribution Amplitude p, collaboration with Polytechnique/Mainz) - - - - - • dE/dx measurements (STT) + EMC PWO4 response to e/ Orsay, GDR

  30. Thank you for your attention Orsay, GDR

  31. - - - - Nb of counts for pp→e+e- ~100 days, L = 2. 1032 cm-2s-1 2 fb-1 6 104 10 5 80 106 3000 q²=22.3 (GeV/c)² cos(cm) _ _ Feasibility study of proton electromagnetic form factor measurements Direct access to |GE| and |GM| via lepton angular distributions Counting rate estimates: Challenges: • at large q2: low cross-sections and low sensitivity to GE • Huge hadronic background  (pp +-) /  (pp e+e-) ~106 - Orsay, GDR

  32. Orsay, GDR

  33. Transverse polarized beam Q2 = 5.4 (GeV/c)2 Q=18o E M Interf. Proton electromagnetic form-factors: what can we do with PANDA? With a transversely polarized beam…. access to Im(GEGM*) New information, very helpful to discriminate models Can be done at PANDA with transverse polarized beam ! Orsay, GDR

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