Klaus Peters RuhrUniversitt Bochum JINR Dubna Workshop Nov
Klaus Peters Ruhr-Universität Bochum JINR Dubna Workshop, Nov 20, 2003 Exotic Hadrons @ Panda
Understanding QCD at small Energies Increase precision measure static properties of well known states Increase the database of decays search for unusual decay modes to gain information Put the hadrons to the limits put the hadrons in vacuum with different baryon density Excite additional modes search for gluonic and radial excitations of hadrons search for gluonic excitation of the strong vacuum 2 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
Objects of Interest Quark Anti. Quark Mesons/Baryons Molecules/Multiquarks Hybrids Glueballs 3 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
Light Meson Spectrum qq Mesons Each box corresponds to 4 nonets (2 for L=0) (L = qq angular momentum) 2–+ 0–+ 2+– 2–+ Glueballs 2. 0 1. 5 Hybrids 2. 5 Radial excitations 1–– 1–+ 1+– 1++ 0+– 0–+ exotic nonets Lattice 1 -+ 1. 9 Ge. V 0++ 1. 0 L=0 4 0++ 1. 6 Ge. V 1 2 3 4 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
Level Mixing Kaon mixing Light quark problem the mixing strong interaction C undefined K 1 A-K 1 B Isoscalar mixing Isospin mixing strong interaction IG, JPC identical η-η‘ elm interaction ΔI=1 ρ-ω Mixing broad states high level density JPC=JP+ a 1 f 1’ K 1 B JPC=JP- b 1 h 1’ K 1 A Glueball mixing Hybrid mixing I=1 I=0 nn I=0 ss I=½ 5 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
Level Mixing Light quark problem the mixing Mixing broad states high level density Better: narrow states and/or lower level density charmed systems ! 6 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
Charmed Hybrids LQCD: gluonic excitations of the quark-antiquark-potential may lead to bound states S-potential for one-gluon exchange P-potential from excited gluon flux m. Hcc ~ 4. 2 -4. 5 Ge. V/c 2 V(R)/Ge. V Klaus Peters, U Bochum, Hybrids and Glueballs P 4 ψ‘ 3. 5 3 Light charmed hybrids could be narrow if open charm decays are inaccessible or suppressed 7 Hcc DD S χc R/r 0 J/ψ 1 2 important <r 2> and r. Breakup Nov 20, 2003
Simplest Hybrids S-Wave+Gluon (qq)8 g with ()8=coloured 1 S ¯ 3 S + 0 1 combined with a 1 or 1 gluon L S=S 1+S 2 J=L+S P=(-1)L+1 S 1 C=(-1)L+S Gluon 1– (TM) 1+(TE) 1 S 0, 0–+ 1++ 1–– 3 S 1, 1–– 0+- 0–+ 1+- 1–+ 2+- 2–+ Exotic JPC cannot! be formed by qq 8 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
LQCD ccg 1 -+ vs. cc 1 -- (J/y) 1 -+ Group Reference isotropic MILC 97 PRD 56(1997)7039 4317± 150 isotropic MILC 99 NPB 93 Supp(1999)264 4287 isotropic JKM 99 PRL 82(1999)4400 anisotropic ZSU 02 hep-lat 0206012 isotropic MILC 97 PRD 56(1997)7039 1220± 150 isotropic MILC 99 NPB 93 Supp(1999)264 1323± 130 anisotropic CP-PACS 99 PRL 82(1999)4396 1190 isotropic JKM 99 PRL 82(1999)4400 anisotropic ZSU 02 hep-lat 0206012 4390± 80 4369± 37 D(1 -+, 1 --) 1340± 80 1302± 37 9 m(ccg) Model ± 200 ± 99 m(ccg)- m(cc) ± 200 ± 99 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
Charmed Hybrid Level Scheme 1 -- (0, 1, 2)-+ < 1++ (0, 1, 2)+JKM, NPB 83 suppl(2000)304 and Manke, PRD 57(1998)3829 L-Splitting Δm ~ 100 -250 Me. V/c 2 for 1 -+ to 0+- S-Splittings Page thesis, 1995 and PRD 35(1987)1668 4. 14 (0 -+) to 4. 52 Ge. V/c 2 (2 -+) 2+- 4. 85 1++ 4. 81 1+- 4. 70 2 -+ 4. 52 4. 5 1 -- 4. 48 4. 4 0+1 -+ 4. 47 4. 37 4. 8 4. 7 4. 6 consistent w/LQCD JKM, NPB 86 suppl(2000)397, PLB 478(2000) 151 4. 3 DD** 4. 2 0 -+ 4. 14 4. 1 10 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
Charmed Hybrids – Decays Fluxtube-Model predicts DD**(+c. c. ) decays if ® m. H< 4290 Me. V/c 2 GH < 50 Me. V/c 2 below DD 0(+c. c. ) Some exotics can decay neither to DD nor to DD*(+c. c. ) e. g. : JPC(H)=0+J/ψf 2, J/ψ(ππ)S, ηch 1 cc 0 w, cc 0 f, cc 2 w, cc 2 f, h 1 cη Small number of final states with small phase space favours a narrow resonance if DD**(+c. c. ) possible ® still very small phase space But! be prepared for surprises measure DD nor to DD*(+c. c. ) waves as well 12 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
Charmed Hybrids – Decays of 1 -+ a very likely decay mode will (could? ) be a cc(ππ)S C. Michael, hep-lat 0207017 preferably using π0π0 to avoid ρ(770) contamination use charged mode π+π- for comparison detect the cc in the radiative decay to J/ψ detect the soft photon and the lepton pair Needed Serious calculations for production and partial decay widths for ccg 13 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
Proton-Antiproton Annihilation Formation only selected JPC p p Production all JPC available p p 14 recoil Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
Proton-Antiproton Annihilation Formation only selected JPC p p p H p p nng G H ssg/ccg p Production all JPC available p H p nng p H p G ssg/ccg M p M Gluon rich process creates gluonic excitation directly ss/cc requires the quarks to annihilate (no rearrangement) yield comparable to charmonium production even at low momenta large exotic content has been proven 15 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
Heavy Glueballs 0+- Light gg/ggg-systems are complicated to identify (mixing!) Exotic heavy glueballs m(0+-) = 4140(50)(200) Me. V m(2+-) = 4740(70)(230) Me. V Width unknown, but! 2+- 2++ nature invests more likely in mass than in momentum newest proof: double cc yield in e+e- Flavour-blindness predicts decays into charmed final states too Same run period as hybrids In addition: scan m>2 Ge. V/c 2 16 Klaus Peters, U Bochum, Hybrids and Glueballs Morningstar, Peardon, PRD 60(1999)34509 Morningstar, Peardon, PRD 56(1997)4043 Nov 20, 2003
4 -Quark Formation Proton-Antiproton contains already a 4 -Quark-System Idea: Dilepton-Tag from Drell-Yan-Production Advantages Trigger less JPC-Ambiguities 1200 E. /day @ 12 Ge. V 300 E. /day @ 5 -8 Ge. V antiproton -Beam (for L=1032 cm-2 s-1) 17 Klaus Peters, U Bochum, Hybrids and Glueballs Bannikov, Gornuschkin, Kopeliovich, Krumshtein and Sapozhnikov, JINR E 1 -92 -344 (1992) Nov 20, 2003
Θ+ @ various experiments LEPS(SPRing-8), Diana(ITEP), Clas(JLAB) Saphir (Elsa) 18 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
Penta. Quark Picture Jaffe & Wilczek hep-ph/0307341 Karliner & Lipkin hep-ph/0307343 In a multi quark picture n. K+ has an anti-strange quark and several light quarks p. KS has no defined strangeness and thus only a supporting evidence Jaffe-Wilczek picture Anti-quark act as a junction between two diquarks Basic idea Replace the anti-quark by other anti-quarks – like anti-charm several quark combinations for each charge ΘC-|cdddd>, |cssss> ΘC |cuddd>, |cudds>, |cudss>, |cusss> ΘC 0 |cuudd>, |cuuds>, |cuuss> ΘC + |cuuud>, |cuuus> ΘC++ |cuuuu> plus all isomeres 19 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
ΘC 0 |cuudd>, |cuuds>, |cuuss> Is the most discussed anti-charm penta-quark |cuudd> would decay to ND final states like n. D 0 or p. Dproblematic below the ND threshold of ~2. 8 Ge. V/c 2 (many weak channels NKX possible, signature unclear) |cuuds> would decay to p. DSbut also below the open charm threshold (~2. 91 Ge. V/c 2) there is the clean channel pfp- which would also be used for the p. DSselection |cuuss> would decay to Σ+DS- and Ξ 0 D 0 but also below the open charm threshold (~3. 15 Ge. V/c 2) there is the clean channel Σ+fπ- which would also uncooled p beam or be used for the Σ+DS- Implies selection. with Fermi-momentum (there are some otherformation weak channels a nuclear target with ΞKX with unclear on signature) 20 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
Exotics in Proton-Antiproton Exotics are heavily produced in pp reactions High production yields for exotic mesons (or with a large fraction of it) 3π0 f 0(1500)π ® ~25 % in 2ηπ0 π1(1400)π ® >10 % in π±π0η Crystal Barrel Interference with other well known (conventional) states is mandatory for the phase analysis 21 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
Accessible Hadrons at PANDA @ GSI Charmed states p Momentum [Ge. V/c] 0 4 ΛΛ ΣΣ ΞΞ Two body thresholds Molecules Gluonic Excitations 2 ΩΩ 6 8 DD D s qqqq Ω cΩ c ccg nng, ssg Hybrids+Recoil ccg ggg, gg Glueball exotic charmonium ggg Glueball+Recoil qq Mesons Λ cΛ c Σ cΣ c ΞcΞc ccqq nng, ssg Hybrids 10 12 15 light qq π, ρ, ω, f 2, K, K* 1 2 cc J/ψ, ηc, χc. J 3 4 conventional charmonium 5 6 Mass [Ge. V/c 2] 22 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
Accessible Hadrons at PANDA @ GSI Glueballs p Momentum [Ge. V/c] 0 4 ΛΛ ΣΣ ΞΞ Two body thresholds Molecules Gluonic Excitations 2 ΩΩ 6 8 DD D s qqqq Λ cΛ c Σ cΣ c ΞcΞc Ω cΩ c ccqq nng, ssg Hybrids 10 12 15 ccg nng, ssg Hybrids+Recoil ccg ggg, gg Glueball glueballs ggg Glueball+Recoil qq Mesons light qq π, ρ, ω, f 2, K, K* Other exotics with identical decay channels ® same region 23 Klaus Peters, U Bochum, Hybrids and Glueballs 1 2 cc J/ψ, ηc, χc. J 3 4 5 6 Mass [Ge. V/c 2] Nov 20, 2003
Lessons from LEAR Full solid angle no missing particles (photons!) no “dead” regions Merged π0 are easy to handle cosq “moderate” angular resolution sufficient Low thresholds Emin~20 Me. V in the electromagnetic detector f (f)-Tag ff and recoil f K-Trigger/K-Id 3 p 0 Emin Eg KS-Trigger Kaon ID @ high energies 24 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
It’s All a Question of Statistics. . . pp ® 3π0 with 100 events 25 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
It’s All a Question of Statistics. . . pp ® 3π0 with 100 events 1000 events 26 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
It’s All a Question of Statistics. . pp ® 3π0 with 100 events 10000 events 27 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
It’s All a Question of Statistics. . . pp ® 3π0 with 100 events 100000 events 28 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
p in Flight – no longer a challenge! Crystal Barrel proved annihilation in flight can be analyzed unambiguously Formation: two body decays, where at least one particle carries spin! ~10 k events L up to 6 Production: small recoil momenta reduce the available phase space and the contributing waves dramatically alternative: integration of the production process Peters, NPA 692(2001)295 29 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
Summary & Outlook Investigation of exotics is the key tool for the investigation of gluonic degrees of freedom inside hadrons Panda@HESR will survey the mass region from ~2 to more than 4 Ge. V/c 2 in formation and production processes. . . to measure the whole spectrum of heavy exotics 30 Klaus Peters, U Bochum, Hybrids and Glueballs Nov 20, 2003
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