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Physics with open charm mesons at. Outline: Physics foundations; Experimental techniques; Capabilities of the PANDA@FAIR; Summary. Andrey Sokolov Institute of Nuclear Physics , Research Center Jülich, Germany. The structure and dynamics of hadrons
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Physics with open charm mesons at Outline: • Physics foundations; • Experimental techniques; • Capabilities of the PANDA@FAIR; • Summary. Andrey Sokolov Institute of Nuclear Physics, Research Center Jülich, Germany The structure and dynamics of hadrons International Workshop XXXV on Gross Properties of Nuclei and Nuclear Excitations, Hirschegg, Kleinwalsertal, Austria, January 14 - 20, 2007
Panda Physics Overview • Charmonium spectroscopy: • Precision M and Γ measurement: qq – potential. • New states above DD threshold. • Charmed hybrids and glueballs; • Interaction of charmed particles with nuclei; • Hypernuclei; • Further options: • Open charm physics • Wide angle compton scattering; • Baryon-Antibaryon production; • CP-Violation (Λ,D). Andrey Sokolov
Charmonium spectroscopy The energy region above the DD threshold isvery poorly known: • The higher vector states ((3S), (4S), (5S) ...)have not all been confirmedby the latest measurements by BES. • In this region the narrow D-states are expected!!! Andrey Sokolov
by BELLE by CDF y’ppJ/y X(3872) 10 seffect 11.6 s effect Charmonium Spectroscopy A new narrow resonance called X(3872) was observed in 2003: M = 3872. 0 ± 0.6 ±0.5MeV G < 2.3 MeV at 90% C.L. The other states Y(3940), Y(4260),X(3943),Z(3934), ψ(4320) have been observed in recent years Andrey Sokolov
The Ds± Spectrum |cs> + c.c. was not expected to reveal any surprises, but… 0- 1- 0+ 1+ 2+ 3- Open Charm Spectroscopy • In Heavy-Light systems • like H-atom; • ordered by property of the light quark; • approximate j degeneracy; • the large gap between j=3/2 and j=1/2 was unexpected. j=L+sL J=j+sH m [GeV/c2] Ds1 }j=3/2 D*K Ds2* }j=1/2 DsJ (2458) D0K DsJ* (2317) Ds* Ds in 2003 BaBar and CLEO observed two new narrow Ds mesons with surprisingly low masses. JP Andrey Sokolov
(cs)– A Heavy-Light System Andrey Sokolov
ECM Production mechanism • e+e- interactions: • Only 1-- states are directly formed; • Other states require: • ISR; • B meson decays; • higher order process (γγ fusion). • pp reactions: • All meson states directly formed(very good mass resolution) • other states can be studied using production mechanism. } low cross-section, mass resolution determined by detector performance Andrey Sokolov
Energy dependency of cross section for HH Effect of finite momentum spread Andrey Sokolov
Benchmark Channels Analysis Following reaction were chosen to demonstrate the physics performance of the PANDA detector: Andrey Sokolov
Production cross-section The production cross-section was estimated using the Breit-Wigner formula: as a result the maximum total cross-section is: and the signal to background ratio is: Andrey Sokolov
Proposed PANDA Detector beam Andrey Sokolov
Micro-Vertex Detector • Displaced vertices of open charm and strangeness with precision ~ 70 μm; • Build on ATLAS experience with hybrid detectors; • Silicon pixel (2-4 layers) and strips (2 layers); • ~7.2 million barrel pixels, ~2 million forward pixels; • R&D: • Requirements on pixel size and orientation; • Investigate photon conversions; • Electronics. Andrey Sokolov
300mm 400mm Micro-Vertex Detector Andrey Sokolov
Simulation of ψ(3770) • Selection criteria: • Kaon ID (only by DIRC and RICH); • D-meson invariant mass; • D-meson secondary vertex fit; • Kinematical constrain on ψ(3770) mass; • Missing mass selection (Invariant mass resolution σ=10MeV). • Single D-meson reconstruction efficiency - 26%; • ψ(3770) reconstruction efficiency - 4.2%; • Background suppression factor - 2×109; • Signal/background ratio ~ 3. Andrey Sokolov
Reconstruction of D and Ds mesons * Only one kaon identification is required. Andrey Sokolov
Total Reconstruction Efficiency * Only one kaon identification is required. Andrey Sokolov
Summary • There are many open questions for open charm and charmonium above the DD threshold. • The PANDA detector will perform high resolution spectroscopy with p-beam and provide new data on this topic. • The Micro-Vertex Detector was designed for the reliable detection of D-mesons and its decay products. • Simulation results demonstrate the good reconstruction efficiency for D-mesons. • Very high background suppression is achieved. Andrey Sokolov
Panda Participating Institutes more than 300 physicists (48 institutes) from 15 countries: 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 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 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 Andrey Sokolov
New Charmonium Resonances • X(3872),Belle 09’2003, 1++, χc1´ or D0D* molecule • decays into J/ψπ+π-, J/ψπ+π-π0, J/ψγ, D0D* • Y(3940),Belle 09’2004, JP+, 23P1 or Hybrid?? • decays into J/ψω • Y(4260), BaBar 06’2005, 1--, 23D1 (BaBar) or 43S1 (CLEO) or Hybrid • decays into e+e-, J/ψπ+π-, J/ψπ0π0, J/ψK+K- • X(3943), Belle 07’2005, 0-+, ηc´´ • decays into D0D* • Z(3934), Belle 07’2005, 2++, χc2´ • decays into γγ, DD • ψ(4320), BaBar 06’2006, ?, Hybrid Andrey Sokolov
_ _ p p X X : at threshold: far above threshold: Threshold Measurement ratio depends only on G, M, and s A. Gillitzer Andrey Sokolov
100 m Facility for Antiproton and Ion Research HESR Andrey Sokolov
from RESR High Energy Storage Ring • Storage ring for p: • Np = 5×1010, Pbeam= 1.5-15 GeV/c; • High density target: • pellet 1015 atoms/cm3, cluster jet, wire; • High luminosity mode: • Δp/p = 10-4, stochastic cooling, L = 1032 cm-2s-1; • High precision mode: • Δp/p = 3×10-5, electron cooling, L = 1031 cm-2s-1. Andrey Sokolov
Simulation of the D-mesons Vertex position Invariant mass of D - meson • 1000 decays were simulated: • Here D-mesons decayed at the point (0.1,0.1,0.4)mm. • Kaon ID was required. • Three tracks were refitted to the common vertex. Andrey Sokolov
ψ(3770) Invariant Mass Resolution σ(Minv) = 10 MeV Andrey Sokolov