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Recent results from the E852 data analysis

Recent results from the E852 data analysis. Motivation, E852 vs GlueX PWA basics p 0 p 0 production hp and h ’ p spectra : have we seen exotics yet ? Computational challenge Outlook. Why mesons ?. ‘Simplest’ QCD states Lab for fundamental symmetry tests

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Recent results from the E852 data analysis

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  1. Recent results from the E852 data analysis • Motivation, E852 vs GlueX • PWA basics • p0p0 production • hp and h’p spectra : have we seen exotics yet ? • Computational challenge • Outlook

  2. Why mesons ? ‘Simplest’ QCD states Lab for fundamental symmetry tests Heavy QQ are non-relativistic Light meson are chiral eigenstates Beyond the quark model : glueballs, exotics Bridge between QCD and the S-matrix theory DcSB quark model JPC = 0--,0+-,1-+,2+-, L

  3. Meson spectroscopy : open issues over O(100) light mesons listed in the PDG ~ O(10) in the summary tables ~ O(1) properly described

  4. a M2x = (pa + pb)2 p-, g b S = (pg + pp)2 p t=(p’N – pp)2 N’ s » 40 GeV2 , Ep, LAB =18 GeV s . 20 GeV2 , Eg, LAB =8-9 GeV t < 1 GeV2 t < 1 GeV2 Mx. 3 GeV Mx. 2.5 GeV Kinematics of peripheral production t/s << 1 GlueX E852

  5. … the less you know the more ambiguous the answer … 0 physics input “maximal’ ambiguity some physics input “moderate” ambiguities know everything no ambiguities You do it in all possible way to study systematics

  6. a c a c t=sac s=sab a b d b d Dynamics of peripheral production I s/t !1 T(s,t) x(t)b(t) sa(t) L = Rea(t) Resonance (or bound state Ima=0)

  7. Quasi-two body reactions p-(18GeV) p  a2 p  h p0 n t E852 p- a2 s dN/dt p n Natural exchange (r) Unnatural exchange (b1)

  8. t1 p0 p- M p0 s s1 p- p0 p a1 t _ p0 n a II Multiple particle production p- p !p0p0 n Regge + particle 4 point function s/t,s/t1,s/M2!1 t,a M2 ~ s M2<<s ~FESR~

  9. p- p !p0p0 n (J. Gunter et al.) 2001 f2(1270) s(400-1200) p0p0 spectrum

  10. Combined analysis of CERN-Krakow-Munich and E852 data L.Lesniak at al. good bad

  11. O(p2p/f2p) p p = Low order c expansion p p + Higher order c expansion + unitarization Interplay between “elementary” (CDD) and “dynamical” resonances

  12. pp (S=I=0) pp 2 Resonaces @ ~1.3, 1.5 GeV pp+KK pp only (no KK, no resonances)

  13. “Global features” of the hp0, hp-, h’p- production hp0 Mass dependence t-dependence Relevant partial waves : S D0 D- Po P- (unnatural) D+ P+ (natural)

  14. p- p !hp0 n (M.Swat, Ph.D thesis) 2003 (A.Dzierba et al.) 2003 a0 and a2 resonances

  15. hp0 vs hp- C is a good quantum number ao and a2 are produced (helps with ambiguities)

  16. Work in progress on full hp- sample O(100K) events ! very low t<0.1 GeV2 a0(980) not seen before r exchange

  17. P-wave results from the hp0 data p1(900 – 5GeV) emerges No consistent B-W description of the P-wave fund when all helicity amplitudes where taken into account Intensity in the weak P-waves is strongly affected by the a2(1320), strong wave due to acceptance corrections

  18. 1 BW resonance in P+ 2 BW resonances in D+ a2(1800) = ? a2(1320) E852 h’p- analysis

  19. What is the origin of the P-wave in the hp, h’p … combine Regge description with chiral constraints M s>>t,M Chiral Regge t vs quasi-two body (resonance) rescattering (dual) to diffraction

  20. p- p !hp- p Results of coupled channel analysis of p- p !h’p- p D D P S P P-wave comes entirely from background : no resonances needed

  21. 1-+ exotic : current status hp- : p1(1400) G > 350 MeV h’p- : p1(1600) G > 350 MeV hp0 : p1(1400) G > 350 MeV Can be explained in terms of hp - h’p rescattering Constrained by the standard SU(3)L£ SUR(3) £ UA(1) effective lagrangian Currently is being reanalyzed Using 150M (full) event sample (compared to 250K) rp : p1(1600), G < 200 MeV

  22. An Exotic Signal in 3p Correlation of Phase & Intensity Leakage From Non-exotic Wave due to imperfectly understood acceptance Exotic Signal

  23. p- p !p-p+p- p E852 2003 Full sample CERN ca. 1970 BNL (E852) ca 1985 Software/Hardware from past century is obsolete

  24. gp vs pp data Compare statistics and shapes Adams ’93 (E852) p- p -> p+ p-p+ p @ 18 GeV Condo’93 g p -> p+ p-p+ n @ 19.3 GeV a2 SLAC 28 p1 ? Events/50 MeV/c2 p2 a1 SLAC BNL 4 1.0 1.5 2.0 2.5

  25. 1-+ exotic : S=1, L=1 g --> r(JPC=1--) --> p1(JPC=1-+) VMD “pluck” the string (S=1,LQQ=0->Lg=1) Photo production enhances exotic mesons Condo’93 OPE

  26. p- p -> X0 n g p -> X+ n 18GeV a2 10% p1 5 GeV a2 In photoproduction p1 ~ 50% - 100% a2 p1 8 GeV M.Swat, AS

  27. Computational challenge p- p !p-p+p- p Step 1 - Reconstruction and Monte Carlo 50M 25M M.C. data (150M) Reconstruction and Kinematic Fitting More Filters 16M 9M Data (78M) This involves several hours of M.C.generation and staging of about 1TB ofdata to disk and processing Time required: about a weekPerhaps re-done 2 or 3 times Multiplepasses tounderstandcuts

  28. p- p !p-p+p- p Step 2 - Preparing Data and Fits p- Current model resonance region p- a2,a1,p2L p+ with the existing software design this can take up to 1 week ! on 100 processors(40 x 80 x 10 = 32000 files) r,f2,f0,L p- a n p This is the inputto the fitter. Each time a changeis made to the modelthe inputs must beregenerated For each eventcompute massesand angles andall invariants and waves thatdepend on massesand angles Typical # ofamplitudes: 40 or so 150M 240 GB This is being redesignedin current version this step takes < 1h ! 25M 40 GB 15 GB 9M

  29. MANTRID Modern amplitude analysis AVIDD cluster (Analysis and Visualization of Instrument-Driven Data) 2x208 2.4 GHz Pentium (IUB + IUPUI) Original E852rp exotic based on0.5M events Now processing 10M 36-processor cluster with 1.6Tb of storage

  30. Preliminary results from full E852 sample p2(1670) a2(1320) Chew’s zero ? Interference between elementary particle (p2) Or the CDD pole with the unitarity cut

  31. Inelastic diffraction : is p(1800) a hybrid ? ds/dt = Ae10t

  32. Why Hall D can resolve issues in meson spectrum • Several orders of magnitude increase in statistics • “Unlimited” computational resources • New developments in theory, LGT, c EFT • High energy, intensity, polarized photon beams

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