– A Novel Detector For Frontier Physics Andrey Sokolov Institute of Nuclear Physics, Jülich Research Center, Germany XVIII International Baldin Seminar on High Energy Physics Problem - “Relativistic Nuclear Physics & Quantum Chromodinamics”

Andrey Sokolov 2 Outline PANDA Physics Program  Charmonium  Open charm Experimental Technique Summary

Andrey Sokolov 3 Open Questions of QCD Although QCD is the widely accepted theory of strong interactions, an exact calculation of hadrons properties from the QCD Lagrangian is still very difficult. Phenomenological models are used instead. Such models are working well at small distances (< 0.1 fm). But at large distances (≈ 1 fm) perturbative theory is no longer applicable.

Andrey Sokolov 4 QCD – Running Coupling Constant perturbative strong transition from perturbative to non-perturbative regime Q 2 [GeV 2 ] perturbative QCDconstituent quark confinement mesons and baryons RnRn r [fm]

Andrey Sokolov 5 Open Question of QCD In non-perturbative regime interaction of the quarks and gluons is highly non-linear. Because of that open questions appear such as: Why are quarks confined within hadrons? What is the origin of hadron masses? Do hybrids ( qqg ) and glueballs ( ggg ) exist? etc.

Andrey Sokolov 6 Panda Physics Overview Charmonium and open charm spectroscopy; Charmed hybrids and glueballs; Interaction of charmed particles with nuclei; Hypernuclei; Many further options:  Wide angle compton scattering;  Baryon-Antibaryon production;  CP-Violation (Λ,D).

Andrey Sokolov 7 Why is Charmonium Interesting ? The (cc) system can be described in terms of non-relativistic potential models → values of the coupling constant α S ≈ 0.3, β≈ 0.2 are determined;  α S ≥ 0.7 for u,d,s systems ; (cc) system has only 8 bound states in ~ 0.8 GeV mass interval;  more than 100 states in u,d,s systems; All states have small widths (≤ 20 MeV) and are very well resolved; Antiproton beam of 6 to 15 GeV/c momentum is required;  for (bb) system p beam up to 60 GeV/c is required, cross section is much lower, absolute precision is worser; Non-relativistic potential models + Relativistic corrections + PQCD + Lattice calculations

Andrey Sokolov 8 The Non-Relativistic Potential The functional form of the potential is chosen to reproduce the known asymptotic properties of the strong interaction. Small distances asymptotic freedom, the potential is Coulomb-like: At large distances confinement:

Andrey Sokolov 9 QED and QCD Bound States Electrodynamic and Chromodynamic spectrum look similar (not too scale)  for infinite quark masses Charmonium is a positronium of QCD A Coulomb-like Potential seems to be a good approach

Andrey Sokolov 10 Charmonium Spectroscopy 5 new measurement of  c mass, but …

Andrey Sokolov 11 Charmonium Spectroscopy Five new measurements published , four by e+e- experiments

Andrey Sokolov 12 Charmonium Spectroscopy Inconsistency in  c mass and width η´ c unambiguously seen, although …

Andrey Sokolov 13 Belle Charmonium Spectroscopy Discovery of η c by Belle in B π η c (K K π ) confirmed by BaBar, Cleo Disagreement of experiments on the mass and with early findings by Crystal Ball ( σ deviation!). Only marginal consistency with most theoretical predictions. Width measured only at 50 % precision.

Andrey Sokolov 14 Charmonium Spectroscopy Inconsistency in  c mass and width η c ´ unambiguously seen, although … h c seen with poor statistics…

Andrey Sokolov 15 Charmonium spectroscopy This singlet P resonance is very important in determining the spin dependent components of the the q q confinement potential. Two recent results, presented at conferences, and an early E760 result. Agreement on the mass at the 8.5 % level. E835 C. Patrignani, BEACH04 presentation e + e -  Ψ π 0 h c h c η c  h c  c   c hadrons M(h c )=3524.40.9MeV/c 2 Cleo E760: M= 0.18±0.19 MeV/c 2 In h c J/Ψπ 0 (1992) M=3525.80.2±0.2 MeV/c 2 pp h c  c 

Andrey Sokolov 16 Charmonium Spectroscopy Inconsistency in  c mass and width η´ c unambiguously seen, although … h c seen with poor statistics… States above DD thr. are not well established

Andrey Sokolov 17 Charmonium spectroscopy The energy region above the DD threshold at 3.73 GeV is very poorly known. Yet this region is rich in new physics. The structures and the higher vector states (  (3S),  (4S),  (5S)...) observed by the early e + e - experiments have not all been confirmed by the latest, much more accurate measurements by BES. This is the region where the first radial excitations of the singlet and triplet P states are expected to exist. In this region the narrow D-states are expected!!!

Andrey Sokolov 18 Charmonium Spectroscopy Inconsistency in  c mass and width η´ c unambiguously seen, although … h c seen with poor statistics… States above DD thr. are not well established New resonances...

Andrey Sokolov 19 Charmonium Spectroscopy X(3872) 10  effect  ’   J/  X(3872) at CDF and D0 M =  0.6  0.5  MeV  < 2.3 MeV at 90% C.L  effect 5.2  effect X(3872) at BaBar 3.5  effect What is the X(3872) ?  Charmonium 1 3 D 2 or 1 3 D 3.  D 0 D 0 * molecule.  Charmonium hybrid (c c g). A new narrow resonance called X(3872) was observed by BELLE

Andrey Sokolov 20 New Charmonium Resonances X(3872), Belle 09’2003, 1 ++, χ c1 ´ or D 0 D* molecule  decays into J/ψπ + π -, J/ψπ + π - π 0, J/ψγ, D 0 D * Y(3940), Belle 09’2004, JP +, 2 3 P 1 ??  decays into J/ψω Y(4260), BaBar 06’2005, 1 --, 2 3 D 1 (BaBar) or 4 3 S 1 (CLEO) or Hybrid  decays into e + e -, J/ψπ + π -, J/ψπ 0 π 0, J/ψ K + K - X(3943), Belle 07’2005, 0 -+, η c ´´  decays into D 0 D * Z(3934), Belle 07’2005, 2 ++, χ c2 ´  decays into γγ, DD ψ (4415), BaBar 06’2006, ?, ??

Andrey Sokolov 21 D sJ (2458) Open Charm Spectroscopy 00 11 00 11 22 33 DsDs Ds*Ds* D sJ * (2317) D s1 m [GeV/c 2 ] D0KD0K D*K D s2 * JPJP The D S ± Spectrum |cs> + c.c. was not expected to reveal any surprises, but… }j=3/2 }j=1/2 In Heavy-Light systems  like H-atom  ordered by property of the light quark  approximate j degeneracy  But the large gap between j=L+s L J=j+s H in 2003 BaBar and CLEO observed two new narrow Ds mesons with surprisingly low masses.

Andrey Sokolov 22 ( cs ) – A Heavy-Light System

Andrey Sokolov 23 e + e - interactions:  Only 1 -- states are directly formed;  ISR;  B meson decays;  two photon fusion;  higher order process; very low cross section pp reactions:  All meson states directly formed (very good mass resolution)  other states (spin exotic) can be studied using production mechanism. Production mechanism } low cross-section, mass resolution determined by detector performance

Andrey Sokolov MeV3510 Crystal Ball ev./2 MeV 100 E CM Experimental technique e + e - interactions:  Γ > 3.8 MeV ; pp reactions:  Γ = 0.91±0.13 MeV. CBall E E 835 ev./pb χ c1

Andrey Sokolov 25 E CM Resonance Scan Measured Rate Beam Profiles Resonance Cross Section small and well controlled beam momentum spread p/p is extremely important

Andrey Sokolov 26 Threshold Measurement at threshold: far above threshold:  ratio depends only on , M, and  s p p  X X : _ _

Andrey Sokolov 27 Energy dependency of cross section effect of finite momentum spread

Andrey Sokolov 28 Facility for Antiproton and Ion Research HESR 100 m

Andrey Sokolov 29 from RESR High Energy Storage Ring Storage ring for p:  N p = 5×10 10, P beam = GeV/c; High density target:  pellet atoms/cm 3, cluster jet, wire ; High luminosity mode:  Δp/p = 10 -4, stochastic cooling, L = cm -2 s -1 ; High precision mode:  Δp/p = 3×10 -5, electron cooling, L = cm -2 s -1.

Andrey Sokolov 30 Proposed PANDA Detector High Rates  10 7 interaction/s Vertexing  K S 0, Y, D, … Charged particle ID  e ±, μ ±, π ±, K, p,… Magnetic tracking EM. Calorimetry  γ, π 0,η Forward capabilities  leading particles Sophisticated Trigger(s)

Andrey Sokolov 31 Proposed PANDA Detector beam

Andrey Sokolov 32 Summary After 30 years since c-quark discovery charmonium system still have many puzzles; Many new charmonium and open charm states have been recently found by e+e- colliders:  No coherent picture → their properties like width and decay channels have to be studied systematically with high precision. The PANDA detector will perform high resolution spectroscopy with p-beam and provide new data on this topic. σ M ≈ 20 keV at

Andrey Sokolov 33 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