July 10, 2006TAPS 2006 Experimental Hall-D and the GlueX Experiment at Jefferson Lab Dr. David Lawrence Jefferson Lab Dr. David Lawrence Jefferson Lab

July 10, 2006TAPS 2006 The Human Scale

July 10, 2006TAPS 2006 Scaling down … Images from Scale:

July 10, 2006TAPS 2006 Protons and Neutrons are each made of 3 quarks

July 10, 2006TAPS 2006 Quarks and Leptons quarksleptons These (plus force carriers) form the “Standard Model” udcstbudcstb = up = down = charm = strange = top = bottom = electron = elec. neutrino = muon = muon neutrino = tau = tau neutrino e  

July 10, 2006TAPS Fundamental Forces in Nature Strong Force Electromagnetic Force Weak Force Gravitational Force (gluons, pions) (photons) (W,Z) (graviton?) g,   W,Z

July 10, 2006TAPS 2006 Quarks must combine into “colorless” particles Mesons: qq 2 quarks Baryons: qqq 3 quarks Each quark has a “color” charge of “red”, “green”, or “blue”

July 10, 2006TAPS 2006 The Flux Tube Model G. Bali

July 10, 2006TAPS 2006 Hybrid Mesons += L = 1 J PC = 1 -+, 1 +- S = 1 L = 0 J PC = 1 -- ( ,  ) J PC = 0 -+, 1 -+, , 1 +-, 2 +- Exotic!

July 10, 2006TAPS 2006 PWA Double Blind Monte Carlo Study of 3 Final states  p n    X   p →  1 + n →  +  +  − n →  +  0  0 n Background waves included a 1 (1260), a 2 (1320) and  2 (1670)

July 10, 2006TAPS 2006 Hybrids Should Appear as a Nonet 9 hybrid particles Should exist for each J PC combination

July 10, 2006TAPS Hybrid Mass spectrum From LQCD calculations. All masses in GeV/c 2 UKQCD(97) Collaboration / MILC(97) MILC(99) (sys) SESAM(98) Mei & Luo(03) Bernard et al.(04)

July 10, 2006TAPS 2006 Exotic quantum numbers imply deeper structure than simple (No mixing with those states!) Light Meson Spectrum

July 10, 2006TAPS 2006 Hybrid Decays X   a 2 X   a 1 X   f 1 X   b 1                                                            Hybrids preferentially couple to states with Both an S-wave and P-wave meson

July 10, 2006TAPS 2006 Hybrid Candidates(?)  1 (1400)1 -+ E852,Crys. Barrel,VES  1 (1600)1 -+ E852,Crys. Barrel,VES  1 (2000)1 -+ E852  2 (1880)2 -+ E852 a 1 (2096)1 ++ E852

July 10, 2006TAPS 2006 The GlueX Detector (all aboard!)

July 10, 2006TAPS 2006 The GlueX Detector 1 Hermetic Design

July 10, 2006TAPS 2006 Incident Photon Energy Need at least E  = 8.4GeV - 9GeV to access masses up to 2.8GeV/c 2

July 10, 2006TAPS 2006 Jlab Upgrade Enhance equipment in existing halls CHL-2 Upgrade magnets and power supplies add Hall D (and beam line)

July 10, 2006TAPS 2006 (FY06 $k direct) Hall D: Cost

July 10, 2006TAPS 2006 Protoyping and Testing

July 10, 2006TAPS 2006 Beam Flux and Event Rate E electron = 12GeV Coherent Peak E  = 9GeV RR 10 7 /s10 8 /s Hadronic Rate 37kHz (total) 1.4kHz (tagged) 370kHz (total) 14kHz (tagged) Trigger Rate 15kHz200kHz Data rate 100 MB/s1GB/s In the first year, GlueX will exceed existing photoproduction data by a couple of orders of magnitude. It will also exceed existing hadroproduction data.

July 10, 2006TAPS 2006 Status of Upgrade CD-0Approve Mission Need CD-1Approve Preliminary Baseline Range CD-2Approve Performance Baseline Range CD-3Approve Start of Construction Start of Data Taking FY2004 FY2005 FY2007 FY2008 FY2011 DOE Order Project Management Manual

July 10, 2006TAPS 2006 Summary To understand confinement, we must understand the glue which binds the quarks. Mapping the spectrum of hybrid mesons would provide great insight into the nature of the glue. A rich spectrum of hybrid mesons is predicted. Models agree the masses of hybrid states should be around 2GeV, some with exotic J PC. GlueX plans to start data taking in 2011

July 10, 2006TAPS 2006 Extra Slides

July 10, 2006TAPS 2006 Hybrid Mesons ~1GeV mass difference

July 10, 2006TAPS 2006 Hybrid Mesons += L = 1 J PC = 1 -+, 1 +- S = 0 L = 0 J PC = 0 -+ ( , K ) J PC = 1 --, 1 ++ Hybrid Meson or , , , … ? P = (-1) L+1 C = (-1) L+S

July 10, 2006TAPS 2006 Why Are Hybrids Hard To See? Most searches involve looking at two body final states. Coupling of hybrids to two body final states is almost nonexistent “Large” masses (~2GeV/c 2 ) About 1/3 of the (exotic) states have broad widths

July 10, 2006TAPS 2006  1 (1400) J PC = 1 -+ Decay modes not “hybrid-like” (Looks like a meson-meson molecule!)

July 10, 2006TAPS 2006  1 (1600) J PC = 1 -+ E852 PRL 86, 3977 (2001)

July 10, 2006TAPS 2006  1 (2000) J PC = 1 -+ E852 hep-ex/ v1 (2004) ; E852 Phys. Lett. B595(2004) f 1 (1285)

July 10, 2006TAPS 2006 Hadroproduction vs. Photoproduction ,K  Non-Exotic Exotic*

July 10, 2006TAPS 2006 Location of Jefferson Lab

July 10, 2006TAPS 2006 Having the angle between the photon polarization vector and reaction plane  provides an additional handle in the analysis that can simplify the PWA. Linearly Polarized  s (produced by coherent bremsstrahlung) The angle  is related to naturality of exchange particle e.

July 10, 2006TAPS 2006 Acceptance of GlueX detector  p →  1 p →  +  − 4  p cos  GJ  GJ Good acceptance of both charged and neutral particles