The PANDA experiment at FAIR

Transcription

1 The PANDA experiment at FAIR Ulrich Wiedner Uppsala University Elba, June 7, 2004

2 The key issues creation of mass QCD exotics (glueballs, hybrids) charmed hadrons in nuclei confinement exotics states of nuclear matter

3 QCD

4 Do glueballs look like... Glueballs, closed fluxtubes and η(1440) Ludvig Faddeev, Antti Niemi and Ulrich Wiedner hep-ph/ , subm. to Phys. Rev. Lett.

5 Creation of Mass A few % of the proton mass is generated due to the Higgs mechanism. Most of the proton mass is created by the strong interaction. HOW?????? We do not understand most of the baryonic mass of the Universe. Glueballs gain their mass solely by the strong interaction and are therefore an unique approach to the mass creation by the strong interaction.

6 QCD systems

7 The glueball spectrum

8 pp π 0 π 0 π 0 Dalitz plot events = entries

9 100 events 10,000 events 1000 events 100,000 events

10 f 0 (1500)

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12 Properties of the π 1 (1400) Decay: (ηπ) L=1 Mass: 1400 ± 30 MeV Width: 310 ± 70 MeV Quantum numbers: J PC = 1 + not possible from qq r J = L r + S r P = ( 1) L+1 C = ( 1) L+S

13 Exotic production in pp:

14 Antiproton annihilations are gluon-rich For energetic reasons higher mass glueballs will not appear in:

15 Decay of charmonium hybrids Lattice results* *UKQCD, C. McNeile et al.; Phys.Rev.D 65:094505, 2002; C. Michael, hep-lat/

16 Results from CLEO B J/ψ φ K Phys. Rev. Lett. 84, 1393 (2000) BABAR can expect ~300 events within 5 years.

17 V( r) hc V( r) = α r r V( r) 4 hc V( r) = αs + K r 3 r V( r) for r Studies of the interplay between perturbative and non-perturbative QCD. distance [m] confinement potential

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19 Production of χ e + e - ψʹ γ χ1,2 γ (γj/ψ) γγ (e + e - ) Reconstruction of invariant mass: detector resolution dependent Formation of χ E 760 (Fermilab) pp χ 1,2 γj/ψ γ (e + e - ) Rate measurement (beam energy dependent): detector resolution independent σ m (beam) = 0.5 MeV

20 * for selected decay mode ** L = cm 2 s 1, 50% accelerator and detector efficiency, integrated luminosity = 8 pb 1 /day *** 1% B.R. for this decay mode

21 clean but understood??

22 Recently discovered states in the charm sector

23 Antiproton-Nucleus Interaction pa (cc) + (A-1) Study properties of charmonium inside nuclear matter.

24 Production of double hypernuclei _ p 3 GeV/c 2. Ξ capture By secondary nucleus H particle?? Λ Λ u u u d s s d d s u d s kaons _Ξ Ξ - capture: Ξ - trigger Ξ - p ΛΛ + 28 MeV 5600 / day γ Λ Λ +23MeV 80 / month 1300 Hz 8000 / month γ 1. Hyperon antihyperon production at threshold 3. γ spectroscopy with Ge-detectors (resolution: kev!)

25 The PANDA detector Detector features: tracking of charged particles measurement and identification of γ, e±, µ±, π±, K±, p, p high rate capability sophisticated and fast trigger scheme

26 Modular Detector Concept solid-state micro tracker high-rate Germanium detector

27 The PANDA group (44 institutions, 320 authors of LOI) Basel, IHEP Beijing, Bochum, Bonn, Brescia, Catania, Cracow, Dresden, JINR Dubna, Edinburgh, Erlangen, Ferrara, LNF Frascati, Frankfurt, Genova, Giessen, Glasgow, KVI Groningen, GSI, FZ Jülich, IMP Lanzhou, Mainz, Milano, TU München, Münster, Northwestern, BINP Novosibirsk, Pavia, Piemento Orientale, IHEP Protvino, Silesia, Stockholm, KTH Stockholm, PNPI St. Petersburg, Dep. A. Avogadro Torino, Dep. Fis. Sperimentale Torino, Trieste, TSL Uppsala, Tübingen, Uppsala, SINS Warsaw, TU Warsaw, AAS Wien

28 Layout of proposed new GSI facility p-beam p-beam

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30 PANDA detector (top view)

31 Pellet stream 1 mm

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34 High-rate TPC with GEM readout

35 Solution: PbWO 4 crystals?

36 SICCAS # H7 T = +6 0 C T = C σ/e=23.1% 137 Cs σ/e=14.5% 137 Cs σ/e=30.7% σ/e=19.5% 22 Na σ/e=13.2% 22 Na σ/e=10.7%!

37 3 3 crystal matrix in tagged photon beam* at Mainz Sigma/E=p0+p1/sqrt(E), Russian Crystals ! / ndf 4.745e-066/ p ! p ! sigma/energy [%] Energy [GeV] Energy resolution (preliminary): 1.59% / E (GeV) %

38 Topics not mentioned CP violation in the charm sector J/ψ nucleon scattering baryon-antibaryon pair production inverted wide-angle Compton scattering open charm physics anti-deuteron production

39 Summary Antiprotons provide a versatile tool for meson spectroscopy experiments. the first glueballs and exotics have been found pp provides the most precise charmonium data hidden and open charm mesons in nuclei. hypernuclear physics Other options: open-charm physics, CP-violation, Inverted Deeply Virtual Compton Scattering Hadron physics has a brilliant future with the FAIR facility and PANDA coming up.