Introduction and Status of QCD Exotics K. Peters GSI Darmstadt/JWGU Frankfurt Hadron Physics at COSY 2005 Bad Honnef, July 25-29

Status of Spin-Exotics Status of Glueball-Search Future Experiments Overview K. Peters - Status of QCD Exotics Introduction Status of Spin-Exotics Status of Glueball-Search Future Experiments Not covered Pentaquarks Baryonium Charmonium-Spectrum

What are EXOTIC hadrons ? K. Peters - Status of QCD Exotics Unconventional hadrons Depends on what is the convention Convention Matter is build out of quarks proton consists of 3 quarks pion consists of a quark and an antiquark Unconventional Hadronic matter is not made entirely out of quarks Quark configurations different from baryons and mesons But not forbidden !

Classification (Close & Lipkin) K. Peters - Status of QCD Exotics Exotics of the first kind External quantum numbers unambiguously incompatible with assignment to baryons or mesons B=1 – baryon-like Q>2, Q<-1, S<-3, S>0, I>3/2, .... B=0 – meson-like |Q|>1, I>1, |S|>2, |C|>2, |S-C|>1, .... 1

Classification (Close & Lipkin) K. Peters - Status of QCD Exotics Exotics of the second kind Combination of quantum numbers not allowed for leading Fock-term Only possible for B=0 JPC = 0--, 0+-,1-+, 2+-, ... cannot be formed by any unexcited qq-System 2

Classification (Close & Lipkin) K. Peters - Status of QCD Exotics Exotics of the third kind – Crypto-Exotics Internal exotic structure like gluonic excitations like N-quarks but no model free signature approach: overpopulation of hadron multiplets unexpected masses and decay properties a well understood conventional meson picture is mandatory 3

Meson Spectrum after the LEAR Era K. Peters - Status of QCD Exotics The LEAR Era with the experiments @ CERN Asterix/Obelix Crystal Barrel Jetset/PS185 WA102/Gams @ BNL E818/E852 @ FNAL E760/E835 @Serpukhov VES/Gams produced impressive results with high statistics and high resolution

SPIN-PARITY EXOTICS (2nd Kind) Search for Hybrids K. Peters - Status of QCD Exotics SPIN-PARITY EXOTICS (2nd Kind) Search for Hybrids

Intermediate State Mixing K. Peters - Status of QCD Exotics Many states may contribute to a final state not only ones with well defined (already measured) properties not only expected ones Many mixing parameters are poorly known K-phases SU(3) phases In addition also D/S mixing (b1,a1 decays)

S-Wave+Gluon (qq)8g with ()8=coloured 1S0 ­¯ 3S1 ­­ Simplest Hybrids K. Peters - Status of QCD Exotics S-Wave+Gluon (qq)8g with ()8=coloured 1S0 ­¯ 3S1 ­­ combined with a 1+ or 1- gluon Gluon 1– (TM) 1+(TE) 1S0, 0–+ 1++ 1–– 3S1, 1–– 0+- 0–+ 1+- 1–+ 2+- 2–+ Meson – Hybrid Mixing q g MIX g FSI

Fluxtube Predictions (u,d)g (n,s)g ccg K. Peters - Status of QCD Exotics N. Isgur, R. Kokoski und J. Paton, Phys. Rev. Lett. 54 (1985) 869 and refs therein F.E. Close und P. R. Page, Nucl. Phys. B443 (1995) 233 (u,d)g (n,s)g ccg

recent new determination of exotic 1-+ hybrid meson Light-quark hybrids K. Peters - Status of QCD Exotics recent new determination of exotic 1-+ hybrid meson improved staggered fermions (lighter quark masses) quenched and unquenched, Wilson gluon action a ~ 0.09 fm lightest mass still above experiment (around strange quark mass) quenched continuum limit MILC, hep-lat/0301024

Rediscovery of the p1(1400) pd  π-π0η p @ Rest in liq.D2 K. Peters - Status of QCD Exotics pd  π-π0η p @ Rest in liq.D2 πp  π-η p (and π0η n)

Proof of evidence for exotic wave - CB K. Peters - Status of QCD Exotics

Controversary in E852 FSI Description in ηπ- K. Peters - Status of QCD Exotics FSI Description in ηπ- Szczepaniak, et al., PRL 91, 092002 (2003)

Controversary in E852, cont‘d K. Peters - Status of QCD Exotics in E852 in ηπ0 the amplitudes are different for different regions BW solution fails

1400 MeV/c2 region well established π1(1400) Summary K. Peters - Status of QCD Exotics 1400 MeV/c2 region well established phase motion against a2(1320) in π-p interference with ρ(770) in pd @ rest signal in πη is at b1π and f1π threshold influences results line shapes and pole positions affected exotic wave is evident it might span over a wide range is it a Hybrid? probably not – decuplet state?

E852 ρπ K. Peters - Status of QCD Exotics π-p  π-ρ0p  π-π-π+p shows a clear resonance in the 1-+ wave around 1600 MeV/c2

VES η‘π resonant structure η and η‘ are coupled via SU(3) Verification K. Peters - Status of QCD Exotics resonant structure in η‘π at 1600 MeV/c2 in ηπ at 1400 MeV/c2 η and η‘ are coupled via SU(3) any interpretation of the π1 resonances have to explain the difference Verification of πη(') results in ρπ channel ρ(16xx) observed by two independent experiments in ρπ and η‘π E852

E852 f1π and b1π blue one 1-+ pole black two poles c2=70.6/47=1.5 E852 K. Peters - Status of QCD Exotics E852 E852 E852 blue one 1-+ pole black two poles c2=70.6/47=1.5

E852 more b1π first observation of a non 1-+ exotic K. Peters - Status of QCD Exotics first observation of a non 1-+ exotic h2(1950) with JPC=2+- M=1954±8 Γ=138±3 another h2 may be at M=2300

Spin-exotic Summary K. Peters - Status of QCD Exotics thanks to G. Adams, RPI

P P S S Charmed Hybrids LQCD: K. Peters - Status of QCD Exotics 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 mHcc ~ 4.2-4.5 GeV/c2 Light charmed hybrids could be narrow if open charm decays are inaccessible or suppressed V(R)/GeV P P Hcc 4 J/ψ χc ψ‘ S S DD 3.5 3 R/r0 1 2 important <r2> and rBreakup

K. Peters - Status of QCD Exotics GLUEBALLS (usually 3rd Kind)

SU(N) Glueballs on the Lattice K. Peters - Status of QCD Exotics recent study of 0++,2++, 0++* glueballs in SU(N), N=2,3,4,5 masses depend linearly on N large N limits differ little from N=3 Lucini, Teper, JHEP 06, 050 (2001). Morningstar und Peardon, PRD60 (1999) 034509 Morningstar und Peardon, PRD56 (1997) 4043

f0(1500) – Crystal Barrel @ LEAR K. Peters - Status of QCD Exotics f0(1500) – Crystal Barrel (CB) @ LEAR: Das f0(1500) wurde in vielen Zerfallskanälen gefunden: (Bilder von pipi, etaeta, etaeta‘, 4pi und KSKS.) Das Zerfallsmuster und die sehr geringe Breite deuten auf eine exotische Natur hin. Insbesondere sind f0(1370) und f0(1500) nicht kompatibel als isoskalares Paar der skalaren Mesonen. (Kleine Tabelle hierzu.) In allen anderen Nonetts lassen sich alle Zerfälle mit SU(3) gut beschreiben. [Verweis auf Folie SU(3).] f0(1500) is very narrow (~100 MeV/c2) and decays dominantly to (2n)π

fj(1710) in radiative J/y decays K. Peters - Status of QCD Exotics Mark III and DM2 found a scalar resonance @ 1700 MeV/c2 in KK in radiative decays of the J/y It took more than a decade to establish the scalar nature of this object MarkIII DM2

SOZI - DOZI - Analysis f0(1500) in 4π and fj(1710) in KK K. Peters - Status of QCD Exotics f0(1500) in 4π and fj(1710) in KK .........“DOZI”-enhanced ......... both should contain remarkable gg content

Central Production CERN-experiments: WA76, WA91, WA102 K. Peters - Status of QCD Exotics CERN-experiments: WA76, WA91, WA102 Important results in the scalar (ππ,KK,KsKs,4p) tensor (ππ,KK,KsKs,4p) pseudoscalar (KKπ,ππη) sectors But: s ~ 1/M2 no charm-sector partial wave (moment)-analysis complicated little фф,ωω statistics Future: Compass, much higher statistics

Meson Glueball Mixing Physical Masses f0(1370),f0(1500),f0(1710) K. Peters - Status of QCD Exotics Physical Masses f0(1370),f0(1500),f0(1710) Bare Masses: m1,m2,mG (G) (S) (N) f0(1370) -0.690.07 0.150.01 0.700.07 f0(1500) -0.650.04 0.330.04 –0.700.07 f0(1710) 0.390.03 0.910.02 0.150.02 octet piece m1=137720 m2=167410 mG=144324 Lattice of about 1600

K-Matrix approach M= 280 – 1900 MeV Anisovich & Sarantsev K. Peters - Status of QCD Exotics Anisovich and Sarantsev, hep-ph/0204328 K-Matrix approach M= 280 – 1900 MeV Uses data from GAMS at small and large nucleon momentum E852 CERN-Munich scattering Crystal Barrel For the channels ππ, ηη, ηη‘, KK, ππππ No f0(600) = σ Found f0(980), f0(1300), f0(1500), f0(1750) and f0(1200-1600)

DS+  π+π-π+ (+c.c) E791 848 E. D DS BaBar 2903 E. K. Peters - Status of QCD Exotics E791 848 E. E.M. Aitala et al., PRL 765 (2001) D DS BaBar 2903 E. PRELIMINARY B. Lewandowski, Proc. Meson 2002 PHD Th. Deppermann, Bochum 2003 non-unitary approach needs interference of 4 resonances for the strange peak  K-Matrix approach resolves it

D+  π+π-π+ (+c.c) non-unitary approach yields 50% σ K. Peters - Status of QCD Exotics non-unitary approach yields 50% σ  K-Matrix approach removes any σ contribution E791 E.M. Aitala et al., PRD 770 (2002) 1172 E.

Problems in Analysis and Interpretation K. Peters - Status of QCD Exotics I=0,p KK* or c.c. _ p+ W c s _ direct FSI many processes, therefore no trivial production amplitude coupled channels contain very many production amplitudes complicated interferences in K0SK0S contr. from K0K0 and K0K0 W c s _ DCS no only K0K0*+c.c. W c s _ ColorS FSI direct W c s _ FSI direct

most interpretations assume The scalar particles K. Peters - Status of QCD Exotics most interpretations assume the doubtless K0*(1430) from LASS to be the I=1/2-state and that the a0(1400) is the I=1-state two classes of arrangements a0(980) & f0(975) are isospin-partner a0(980) & f0(975) are completely independent a reasonable model must be able to handle the mixing of isoscalars as well as t- and u-channel exchange

Scalar Summary Puzzle still unsolved .... K. Peters - Status of QCD Exotics Puzzle still unsolved ....

2 GeV Tensors Sorted by measured final state Structure unclear K. Peters - Status of QCD Exotics Sorted by measured final state Structure unclear

f2(1920) K. Peters - Status of QCD Exotics

f2(2200) Broad resonance at 2.2 GeV/c2 K. Peters - Status of QCD Exotics Broad resonance at 2.2 GeV/c2

Many Spin-Parity Exotics SUMMARY and OUTLOOK I K. Peters - Status of QCD Exotics Hybrids Many Spin-Parity Exotics π1(1400) *** π1(1600) **** π1(2000) ** h2(1950) * h2(2300) (*) Future investigations GlueX for the light quark sector Panda for the onia and heavy light sector

Too many scalars with an unclear nature SUMMARY and OUTLOOK II K. Peters - Status of QCD Exotics Glueballs Too many scalars with an unclear nature experimental situation fairly good, saturated D(s)-decays can not help solving this issue Many unconfirmed tensors important field for the future to settle the spectrum BESIII and Panda are well suited

K. Peters - Status of QCD Exotics FUTURE EXPERIMENTS

Implications for exotic meson searches K. Peters - Status of QCD Exotics Possible narrow QCD exotic (M=1.6 GeV) (E852 π-p  π+π-π-p) pion Szczepaniak & Swat (01) photon π-p  X0n γp  X+n exotic/non-exotic ~ 0.1 exotic/non-exotic ~ 1

Hall D @ JLab and the 12 GeV Upgrade K. Peters - Status of QCD Exotics Upgrade magnets and power supplies CHL-2 Construction start - 200? Physics - 200?+4

The GSI Future Facility K. Peters - Status of QCD Exotics Panda Existing GSI Facilities

Accessible Charmed Hadrons at PANDA @ GSI K. Peters - Status of QCD Exotics 2 4 6 8 12 15 10 p Momentum [GeV/c] Mass [GeV/c2] Two body thresholds Molecules Gluonic Excitations qq Mesons 1 3 5 Hybrids Hybrids+Recoil Glueball Glueball+Recoil ΛΛ ΣΣ ΞΞ ΛcΛc ΣcΣc ΞcΞc ΩcΩc ΩΩ DD DsDs qqqq ccqq nng,ssg ccg ggg,gg light qq π,ρ,ω,f2,K,K* cc J/ψ, ηc, χcJ ggg exotic charmonium conventional charmonium Other exotics with identical decay channels ® same region

BES III @ BEPC2 BEPC2 will operate as τcf and synchrotron light source K. Peters - Status of QCD Exotics BEPC2 will operate as τcf and synchrotron light source Start of operation 2007

BES III Physics Performance Example K. Peters - Status of QCD Exotics J/ψ  ρ0ηπ0 Well identified ρ(1390) ρ(2300) via partial wave analysis