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Paola Gianotti - LNF Goals and achievements in meson spectroscopy: LEAR and FermiLab activities Overview of the GSI Future Project The Antiproton Physics Program Charmonium spectroscopy Hybrids and glueballs Medium modification of mesons Hypernuclei The PANDA detector concept Conclusions From LEAR to HESR: past, present and future of meson spectroscopy with antiprotons
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Paola Gianotti - LNF Goals and achievements in meson spectroscopy QCD is the accepted theory of strong interaction even if calculating the properties of mesons from the QCD Lagrangian is very difficult phenomenological models are used instead All these models predict in addition to conventional states exotic states with explicit glue content Some of these exotic states have been finaly identified even if our understanding of ordinary mesons is not exhaustive
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Paola Gianotti - LNF Different experimental techniques are used to disentangle these states: Studies of different final states; Selection of special working conditions or final states to filter initial state quantum numbers; Production mechanisms ( collisions, pp annihilation, peripheral or central production, etc). Goals and achievements in meson spectroscopy Meson spectrum consists of an increasingly large number of broad overlapping states crowed in the mass region around 1÷2 GeV.
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Paola Gianotti - LNF The LEAR inheritance Three glueball candidates: f 0 (1500), f 0 (1370), f 0 (1710) 0 ++ (1440) 0 + Two hybrids candidates: 1 (1400), 1 (1600) 1 + Beam intensity10 4 ÷ 10 6 p/s Beam momentum 100÷2000 MeV/c Δp/p10 -3 Machine vacuum10 -11 ÷ 10 -12 Torr circumference78.54 m
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Paola Gianotti - LNF OBELIX A.Bertin et al.,Physics Letters B385, (1996), 493. A.Bertin et al.,Physics Letters B400, (1997), 226. A.Bertin et al.,Physics Letters B361, (1995), 187. F.Nichitiu et al.,Physics Letters B545, (2002), 261. The LEAR inheritance Crystal Barrel
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Paola Gianotti - LNF The Fermilab activity 00 Many results come from E760-E835 experiments at Fermilab Antiproton Accumulator 8·10 11 p per stack accumulation rate 4 · 10 10 p/h p accumulated at 8.9 GeV/c and decelerated decreasing dipole current “fine scan” using stochastic cooling Initial beam intensity 10 12 p Gas jet target density 10 12 ÷10 14 atoms/cm 3 to keep luminosity constant 2·10 31 cm -2 sec -1 Momentum spread p/p 10 -4 → (√s) 200 KeV 8·10 11 p per stack accumulation rate 4 · 10 10 p/h p accumulated at 8.9 GeV/c and decelerated decreasing dipole current “fine scan” using stochastic cooling Initial beam intensity 10 12 p Gas jet target density 10 12 ÷10 14 atoms/cm 3 to keep luminosity constant 2·10 31 cm -2 sec -1 Momentum spread p/p 10 -4 → (√s) 200 KeV
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Paola Gianotti - LNF SIS 100/300 HESR Super FRS NESR CR p Target GSI Future Facility UNILAC SIS FRS ESR Primary Beams 238 U 28+ 1.5 GeV/u; 10 12 /s ions/pulse 30 GeV protons; 2.5x10 13 /s 238 U 73+ up to 25 (- 35) GeV/u; 10 10 /s Storage and Cooler Rings Radioactive beams e – A collider 10 11 stored and cooled p 0.8 - 14.5 GeV Cooled beams Rapidly cycling superconducting magnets Key Technical Features Broad range of radioactive beams up to 1.5 - 2 GeV/u Antiprotons 3 (0) - 30 GeV Secondary Beams From protons to uranium - In future also atiprotons From 1MeV/u to 2 GeV/u - In future up to 30 GeV/u 10 9 to 10 11 particles/cycle - In future 10 12 particles/cycle 0.1Hz to 1Hz repetition rate - In future up to 3 Hz From protons to uranium - In future also atiprotons From 1MeV/u to 2 GeV/u - In future up to 30 GeV/u 10 9 to 10 11 particles/cycle - In future 10 12 particles/cycle 0.1Hz to 1Hz repetition rate - In future up to 3 Hz
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Paola Gianotti - LNF HESR - High Energy Storage Ring High luminosity modeHigh resolution mode p/p ~ 10 -5 (electron cooling) Lumin. = 10 31 cm -2 s -1 Lumin. = 2 x 10 32 cm -2 s -1 p/p ~ 10 -4 (stochastic cooling) Production rate 2x10 7 /sec P beam = 1 - 15 GeV/c N stored = 5x10 10 p Internal Target
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Paola Gianotti - LNF Charmonium spectroscopy Charmonium spectrum is becoming more clear… 5 new measurements of c mass
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Paola Gianotti - LNF Even on the ground state on the simplest parameters there are consistency problems… Five new measurements published 2002-2003, four by e + e - experiments Charmonium spectroscopy
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Paola Gianotti - LNF Charmonium spectrum is becaming more clear… ’ c unambiguously seen Charmonium spectroscopy 5 new measurements of c mass
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Paola Gianotti - LNF 358036003620364036603680 CBALL 86 (2S) → X ’c’c 3637.7±4.4 MeV BELLE 02 B → K (K S K + - ) BELLE 03 e + e - → J/ X CLEO 03 → K S K + - BABAR 03 → K S K + - Mass (MeV) New measurements of mass are consistent! tot = (19 ± 10) MeV Charmonium spectroscopy
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Paola Gianotti - LNF Charmonium spectrum is becaming more clear… Open problems… 5 new measurements of c mass ’ c unambiguously seen h 1c not confirmed States above DD thr. are not well established Charmonium spectroscopy
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Paola Gianotti - LNF Mass Decay channels studied Total BR seen (%) Decay Channels With error <30% cc 2979.6±1.2 2160.33 ’c’c 3654.0±6.0 4~ 00 J/ 3096.92±.01 13544.283 ’’ 3686.09±.03 6277.129 c0 3415.2±0.3 1712.310 c1 3510.59±.10 1333.66 c2 3556.26±.11 1926.310 hchc 2?0 (3770) 3770.0±2.4 2~ 01 (3836) 3836±13 1~ 00 X(3872) 3872.0±0.6 3~ 00 (4040) 4040±10 6~ 01 (4160) 4159±20 1~ 00 (4415) 4415±6 2~ 00
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Paola Gianotti - LNF 35003520 MeV3510 CBall ev./2 MeV 100 E CM CBall E835 1000 E 835 ev./pb c1 Charmonium Physics e + e - → ’ → → e + e - → J / ● e + e - interactions: - Only 1 -- states are formed - Other states only by secondary decays (moderate mass resolution) - All states directly formed (very good mass resolution) → J/→ J/ → e+e-→ e+e- p p → 1,2 ● pp reactions: Br(e + e - → ) ·Br( → c ) = 2.5 10 -5 Br(pp → c ) = 1.2 10 -3
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Paola Gianotti - LNF Exotic hadrons In the light meson spectrum exotic states overlap with conventional states The QCD spectrum is much rich than that of the naive quark model also the gluons can act as hadron components The “exotic hadrons” fall in 3 general categories: (qq) g Hybrids Glueballs (qq)(qq) Multiquarks E x o t i c l i g h t q q E x o t i c c c 1 -- 1 -+ 020004000 MeV/c 2 10 -2 1 10 2
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Paola Gianotti - LNF Exotic hadrons The QCD spectrum is much rich than that of the naive quark model also the gluons can act as hadron components The “exotic hadrons” fall in 3 general categories: (qq) g Hybrids Glueballs (qq)(qq) Multiquarks In the cc meson spectrum the density of states is lower and therefore the overlap
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Paola Gianotti - LNF In the light meson region, about 10 states have been classified as “Exotics”. Almost all of them have been seen in pp... Exotic hadrons Main non-qq candidates f 0 (980)4q state f 0 (1500)0 ++ glueball candidate f 0 (1370)0 ++ glueball candidate f 0 (1710)0 ++ glueball candidate (1410); (1460) 0 + glueball candidate f 1 (1420)hybrid, 4q state 1 (1400) hybrid candidate 1 1 (1600) hybrid candidate 1 (1800) hibrid candidate 0 2 (1900) hybrid candidate 2 1 (2000) hybrid candidate 1 a 2 ’(2100)hybrid candidate 1 ++
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Paola Gianotti - LNF Production all J PC available Formation only selected J PC Exotic mesons are produced with rates similar to qq conventional systems All ordinary quantum numbers can be reached ~1 b All ordinary quantum numbers can be reached ~1 b p p _ G p p _ H p p _ H Glueballs and Hybrids p p _ G M p M H p _ p M H p _ Even exotic quantum numbers can be reached ~100 pb Even exotic quantum numbers can be reached ~100 pb
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Paola Gianotti - LNF p p _ G M p M H p _ p M H p _ production p p _ G p p _ H p p _ H formation
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Paola Gianotti - LNF ●Gluonic excitations of the quark-antiquark-potential may lead to bound states ●LQCD: m H ~ 4.2-4.5 GeV ; J PC 1 -+ Charmed Hybrids ●Flux tube-Model predicts H DD** (+c.c.) decays If m H <4290 MeV/c 2 → H < 50 MeV/c 2 ●Some exotics can decay neither to DD nor to DD*+c.c. –e.g.: J PC (H)=0 +- Flux-tube allowed c0 , c0 , c2 , c2 , c, h 1, h 1c Flux-tube forbidden J/ f 2,J/ ( ) S –Small number of final states with small phase space r 0 =0.5fm BaBar and Belle would expect ~300 evts. each in 5 years not competitive
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Paola Gianotti - LNF Light gg/ggg-systems are complicated to be identified Oddballs: exotic heavy glueballs –m(0 +- ) = 4740(50)(200) MeV –m(2 +- ) = 4340(70)(230) MeV Width unknown, but! –nature invests more likely in mass than in momentum good prob. to see in charm channels –Same run period as hybrids Morningstar and Peardon, PRD60 (1999) 034509 Morningstar and Peardon, PRD56 (1997) 4043 Glueballs
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Paola Gianotti - LNF Mesons in nuclear matter One of the fundamental question of QCD is the generation of MASS The light meson masses are larger than the sum of the constituent quark masses! Spontaneous chiral symmetry breaking seems to play a decisive role in the mass generation of light mesons. How can we check this?
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Paola Gianotti - LNF Mesons in nuclear matter Since density increase in nuclear matter is possible a partial restoration of chiral symmetry ● Light quarks are sensitive to quark condensate Evidence for mass changes of pions and kaons has been observed ● Deeply bound pionic atoms Nucleus-Nucleus CollisionsProton-Proton Collisions K-K- K+K+ K-K- K+K+ f* = 0.78f ● Kaon-production environments
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Paola Gianotti - LNF pionic atoms KAOS/FOPI HESR π K D vacuumnuclear medium ρ = ρ 0 π+π+ π-π- K-K- K+K+ D+D+ D-D- 25 MeV 100 MeV 50 MeV Mass modifications of mesons With p beam up to 15GeV/c these studies will be extended Sub-threshold enhancement for D and D meson production expected signal: strong enhancement of the D-meson cross section, relative D + D - yields, in the near/sub-threshold region. Mesons in nuclear matter pp → D + D - 10 -2 10 -1 1 10 10 2 10 3 (nb) 4567 D+D+ D-D- T (GeV) in-medium free masses
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Paola Gianotti - LNF Mesons in nuclear matter The lowering of the DD thresh. –allow ’, c2 charmonium states to decay into this channel 3 GeV/c 2 Mass 3.2 3.4 3.6 3.8 4 (1 3 D 1 ) (1 3 S 1 ) c (1 1 S 0 ) (3 3 S 1 ) c1 (1 3 P 1 ) c1 (1 3 P 0 ) 3,74 3,64 3,54 vacuum 1010 2020 thus resulting in a substantial increase of width of these states c2 (1 3 P 2 ) (2 3 S 1 ) – states above DD thresh. would have larger width Idea –Study relative changes of yield and width of the charmonium state (3770). BR into (10 -5 in free space) Predictions by Ye.S. Golubeva et al., Eur.Phys.J. A 17,(2003)275
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Paola Gianotti - LNF J/ Absorption in Nuclei e-e- e+e+ J/ p ● Important for the understanding of heavy ion collisions related to QGP ● Reaction p + A → J/ + (A-1) → e + e ● A complete set of measurements could be done - J/ , ‘, J on different nuclear target - Longitudinal and transverse Fermi- distribution is measurable
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Paola Gianotti - LNF s u d s d d s d s s s s 00 Use pp interaction to produce a hyperon “beam” (t~10 -10 s) which is tagged by the antihyperon or its decay products Hypernuclear Physics _ (Kaidalov & Volkovitsky) quark-gluon string model
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Paola Gianotti - LNF - capture: - p + 28 MeV -- 3 GeV/c Kaon s _ trigger p _ 2. Slowing down and capture of in secondary target nucleus 2. Slowing down and capture of in secondary target nucleus 1. Hyperon- antihyperon production at threshold 1. Hyperon- antihyperon production at threshold +28MeV 3. -spectroscopy with Ge-detectors 3. -spectroscopy with Ge-detectors Production of Double Hypernuclei - (dss) p(uud) (uds) (uds)
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Paola Gianotti - LNF Expected Counting Rate Ingredients (golden events) ─ luminosity 2·10 32 cm -2 s -1 ─ + - cross section 2mb for pp 700 Hz ─ p (100-500 MeV/c) p 500 0.0005 – + reconstruction probability 0.5 – stopping and capture probability p CAP 0.20 – total captured - 3000 / day – - to -nucleus conversion probability p 0.05 – total hypernucleus production 4500 /month – gamma emission/event, p 0.5 – -ray peak efficiency p GE 0.1 ~7/day „golden“ -ray events ( + trigger) ~700/day with KK trigger high resolution -spectroscopy of double hypernuclei will be feasible
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Paola Gianotti - LNF Other physics topics Cross section σ ≈ 2.5pb @ s ≈10 GeV 2 L = 2·10 32 cm-2 s-1 → 10 3 events per month Reversed Deeply Virtual Compton Scattering CP-violation (D/ – sector) - D 0 D 0 mixing SM prediction < 10 -8 - compare angular decay asymmetries for SM prediction ~ 2 · 10 -5 Rare D-decays: D + → + (BR 10 -4 ) W+W+ c d
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Paola Gianotti - LNF Detector requests: nearly 4 solid angle(partial wave analysis) high rate capability(2 · 10 7 annihilations/s) good PID( , e, , , K, p) momentum resolution(~1%) vertex info for D, K 0 S, (c = 317 m for D ± ) efficient trigger(e, , K, D, ) modular design(Hypernuclei experiments) Detector General Purpose Detector
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Paola Gianotti - LNF Detector (top view) target spectrometer forward spectrometer micro vertex detector electromagnetic calorimeter DIRC: Detecting Internally Reflected Cherenkov light straw tube tracker mini drift chambers muon counter Solenoidal magnet iron yoke
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Paola Gianotti - LNF PANDA Detector
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Paola Gianotti - LNF PANDA Collaboration At present a group of 300 physicists from 49 institutions of 11 countries Basel, Beijing, Bochum, Bonn, Catania, Cracow, Dresden, Edinburg, Erlangen, Ferrara, Franhfurt, Genova, Giessen, Glasgow, KVI Groningen, GSI, FZ Jülich I + II, JINR, Katowice, Lanzhou, LNF, Los Alamos, Mainz, Milano, Milano Politecnico, Minsk, TU München, Münster, Northwestern, BINP Novosibirsk, Pavia, Silesia, Stockolm, Torino I + II, Torino Politecnico,Trieste, TSL Uppsala, Tübingen, Uppsala, SINS Warsaw, AAS Wien http://www.gsi.de/hesr/panda Spokesperson: Ulrich Wiedner – Uppsala deputy Austria – China - Germany – Italy – Netherlands – Poland – Russia – Sweden – Switzerland - U.K. – U.S.
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Paola Gianotti - LNF Conclusions perform high resolution spectroscopy with p-beam in formation experiments: E ≈ E beam produce, with high yields, gluonic excitations: glueballs, hybrids, multi-quark states ≈ 100 pb study partial chiral symmetry restoration by implanting mesons inside the nuclear medium produce hyperon-antihyperon taggable beams Thanks to the new GSI HESR facility p will be used to...
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Paola Gianotti - LNF TopicCompetitor Confinement Charmonium all cc states with high resolution CLEO-C only 1 –– states formed Gluonic Excitations charmed hybrids heavy glueballs CLEO-C light glueballs Hall-D light hybrids Nuclear Interactions D-mass shift J/ absorption (T~0) Da ne K-mass shift Hypernuclei -spectroscopy of - and - hypernuclei JHF single HN Da ne high luminosity Open Charm Physics Rare D-Decays CP-physics in Hadrons CLEO-C rare D-Decays CP-physics in D-Mesons Competition BES, CLEO, Dane, HallD, JHF
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Paola Gianotti - LNF Final stateCross section# rec. events Meson resonance + anything 100 m b10 50 m b10 2mb2mb10 8 DD 250nb10 7 J/ ( → e + e , ) 630nb10 9 2 ( → J/ ) 3.7nb10 7 cccc 20nb10 7 cccc 0.1nb10 5 HESR/ expected counting rates One year of data taking ≈ 1-2(fb) -1
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