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Recent results from the E852 data analysis Motivation, E852 vs GlueX PWA basics 0 0 production and spectra : have we seen exotics yet ? Computational challenge Outlook

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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 Why mesons ? J PC = 0 --,0 +-,1 -+,2 +-, D SB quark model

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

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S = (p + p p ) 2 t=(p N – p p ) 2 M 2 x = (p a + p b ) 2 a b N p, t/s << 1 Kinematics of peripheral production s. 20 GeV 2, E, LAB =8-9 GeV t < 1 GeV 2 M x. 2.5 GeV s » 40 GeV 2, E, LAB =18 GeV t < 1 GeV 2 M x. 3 GeV E852 GlueX

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

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Dynamics of peripheral production I a b c d t=s ac s=s ab s/t ! 1 T(s,t) (t) (t) s (t) a c b d L = Re (t)Resonance (or bound state Im =0)

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(18GeV) p a 2 p 0 n dN/dt p n - a2a2 t s Natural exchange ( ) Unnatural exchange (b 1 ) Quasi-two body reactions E852

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II Multiple particle production - p ! 0 0 n - p 0 0 n _ s s1s1 M t1t1 t s/t,s/t 1,s/M 2 ! 1 Regge + particle 4 point function t, - 0 0 1 ~FESR~ M 2 ~ s M 2 <~~
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0 0 spectrum f 2 (1270) (400-1200) (J. Gunter et al.) 2001 - p ! 0 n

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

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= O(p 2 /f 2 ) + Low order expansion Higher order expansion + unitarization Interplay between elementary (CDD) and dynamical resonances

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

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Relevant partial waves : S D 0 D - P o P - (unnatural) D + P + (natural) Mass dependence t-dependence Global features of the production

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- p ! 0 n a 0 and a 2 resonances (A.Dzierba et al.) 2003 (M.Swat, Ph.D thesis) 2003

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0 vs - C is a good quantum number a o and a 2 are produced (helps with ambiguities)

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Work in progress on full - sample O(100K) events ! a 0 (980) not seen before exchange very low t<0.1 GeV 2

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P-wave results from the 0 data 1 (900 – 5GeV) emerges Intensity in the weak P-waves is strongly affected by the a 2 (1320), strong wave due to acceptance corrections No consistent B-W description of the P-wave fund when all helicity amplitudes where taken into account

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1 BW resonance in P + a 2 (1320) 2 BW resonances in D + a 2 (1800) = ? E852 analysis

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… combine Regge description with chiral constraints s>>t,M t Regge Chiral M What is the origin of the P-wave in the, rescattering (dual) to diffraction vs quasi-two body (resonance)

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

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- : 1 (1400) > 350 MeV - : 1 (1600) > 350 MeV 0 : 1 (1400) > 350 MeV Can be explained in terms of - rescattering Constrained by the standard SU(3) L £ SU R (3) £ U A (1) effective lagrangian : 1 (1600), < 200 MeV Currently is being reanalyzed Using 150M (full) event sample (compared to 250K) 1 -+ exotic : current status

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

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

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BNL Compare statistics and shapes 28 4 Events/50 MeV/c 2 SLAC 1.02.52.01.5 p vs p data a2a2 a1a1 ? Condo93 p -> + - + n @ 19.3 GeVAdams 93 (E852) p -> + - + p @ 18 GeV

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OPE Photo production enhances exotic mesons --> (J PC =1 -- ) --> 1 (J PC =1 -+ ) pluck the string (S=1,L QQ =0->L g =1) 1 -+ exotic : S=1, L=1 VMD Condo93

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p -> X + n 5 GeV 8 GeV p -> X 0 n 18GeV a2a2 1 a2a2 1 1 a2a2 ~ 50% - 100% 10% In photoproduction M.Swat, AS

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Computational challenge Step 1 - Reconstruction and Monte Carlo Reconstruction and Kinematic Fitting M.C. data (150M) More Filters 50M25M Data (78M) 16M9M This involves several hours of M.C. generation and staging of about 1TB of data to disk and processing Time required: about a week Perhaps re-done 2 or 3 times Multiple passes to understand cuts - p ! - + - p

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This is the input to the fitter. Each time a change is made to the model the inputs must be regenerated 25M 9M 150M For each event compute masses and angles and all invariants and waves that depend on masses and angles Typical # of amplitudes: 40 or so 240 GB 40 GB 15 GB Current model - p ! - + - p - p resonance region a 2,a 1, 2,f 2,f 0, + - - n Step 2 - Preparing Data and Fits with the existing software design this can take up to 1 week ! on 100 processors (40 x 80 x 10 = 32000 files) This is being redesigned in current version this step takes < 1h !

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Modern amplitude analysis AVIDD cluster (Analysis and Visualization of Instrument-Driven Data) 2x208 2.4 GHz Pentium (IUB + IUPUI) MANTRID Original E852 rp exotic based on 0.5M events Now processing 10M 36-processor cluster with 1.6Tb of storage

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Preliminary results from full E852 sample a 2 (1320) 2 (1670) Chews zero ? Interference between elementary particle ( 2 ) Or the CDD pole with the unitarity cut

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Inelastic diffraction : is (1800) a hybrid ? d /dt = Ae 10t

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

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