Klaus Peters Ruhr-Universität Bochum Yokohama, March 3, 2003 Charmed

2March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton Overview Phenomenology of Hybrids Charmed Hybrid Spectrum Experimental techniques Conclusions see also Helmut Koch’s talk on Hadron physics with Panda see also Ted Barnes’ talk on Testing QCD – from LEAR to GSI see also Walter Henning’s talk on The GSI Future Project

3March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton Standard model meson only one leading term Other colour neutral configurations may mix Decoupling is possible only if states are narrow lower density of states leading term vanishes Hadrons are very complicated

4March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton Simplest Hybrids S-Wave+Gluon (qq) 8 g with () 8 =coloured 1 S 0  3 S 1  combined with a 1 + or 1 - gluon Gluon1 –– (TM) 1 +– (TE) 1 S 0, 0 –+ 1 +– 1 –– 3 S 1, 1 –– – – –+ Meson – Hybrid Mixing g MIX g FSI q q

5March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton Charmed Hybrids Gluonic excitations of the quark-antiquark-potential may lead to bound states LQCD: -potential m H ~ GeV Light charmed hybrids could be as narrow as  O(5-50 MeV)   important and r Breakup

6March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton LQCD ccg 1 -+ vs. cc 1 -- (J/) 1 -+ m(ccg)ModelGroupReference 4390±80±200 isotropicMILC97PRD56(1997) ±150 isotropicMILC99NPB93Supp(1999) isotropicJKM99PRL82(1999) ±37±99 anisotropicZSU02hep-lat (1 -+,1 -- ) m(ccg)- m(cc) 1340±80±200 isotropicMILC97PRD56(1997) ±150 isotropicMILC99NPB93Supp(1999) ±130 anisotropicCP-PACS99PRL82(1999) isotropicJKM99PRL82(1999) ±37±99 anisotropicZSU02hep-lat

7March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton Charmed Hybrid Level Scheme 1 -- (0,1,2) -+ < 1 ++ (0,1,2) +- JKM00, NPB83Suppl83(2000)304 and Manke, PRD57(1998)3829 L-Splitting m ~ MeV/c 2 for 1 -+ to 0 +- S-Splittings Page thesis,1995 and PRD35(1987) (0 -+ ) to 4.52 GeV/c 2 (2 -+ ) consistent w/LQCD JKM, NPB86suppl(2000)397, PLB478(2000) DD**

8March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton Fluxtube Meson Hybrid ~ Simplified Lattice Approach Flux (excited Gluon) carries angular momentum

9March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton Charmed Hybrids – Decays Fluxtube-Model predicts DD** (+c.c.) decays ifm H <4290 MeV/c 2 below DD 0 (+c.c.)  H < 50 MeV/c 2 Some exotics can decay neither to DD nor to DD* (+c.c.) e.g.: J PC (H)=0 +- fluxtube forbidden:J/f 2, J/() S,  c h 1 fluxtube allowed: c0 ,  c0 ,  c2 ,  c2 , h 1c  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

10March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton Charmed Hybrids – Decays of 1 -+ a very likely decay mode will (could?) be  c () S a no DD** (+c.c.) needed and fluxtube allowed C. Michael, hep-lat preferably using  0  0 to avoid (770) contamination use charged mode  +  - for comparison detect the  c in the radiative decay to J/ detect the soft photon and the lepton pair

11March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton Double charm production Belle results on e + e - J/ ccJ/ X

12March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton Rest/Flight Production all J PC available Formation only selected J PC see also Diego Bettoni’s talk on Charmonium Production

13March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton Rest/Flight Gluon rich process creates gluonic excitation in a direct way cc requires the quarks to annihilate (no rearrangement) yield comparable to charmonium production even at low momenta large exotic content has been proven Momentum range for a survey p p ~15 GeV p p _ G M p M H p _ p M H p _ p p _ G p p _ H p p _ H Production all J PC available Formation only selected J PC

14March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton Accessible Hadrons Other exotics with identical decay channels  same region mass and phase space of recoil meson for exotic J PC included

15March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton Lessons from LEAR EE 3030 E min cos  Full solid angle no missing particles (photons!) no “dead” regions Merged  0 are easy to handle “moderate” angular resolution sufficient Low thresholds E min ~20 MeV in electromagnetic detector K-Trigger/K-Id K S -Trigger Kaon high Energies

16March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton Signatures, Potential Problems “Leading charmonia” J/, ‘,  ( ‘ ) c,  cj, [DD] a.o.m.? DiLeptons e + e - (Ecal,Trk)  +  - (Trk,Hcal) ()-Tag  and recoil (Trk,Cherenkov) K S (+K ± )-Tag  c and h c (Vtx,Trk,Cherenkov) Photon-Pairs  from cc (Ecal,no-Trk) from  0 and (Ecal) Many information needed on “trigger” level ! see also Jim Ritman’s talk on Detector concepts for Panda

17March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton 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! ~10k 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

18March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton Summary & Outlook Investigation of charmed hybrids is the key tool to the investigation of gluonic degrees of freedom inside hadrons GSI will survey the whole ccg mass region in formation and production processes to measure the whole spectrum of charmed hybrids