Experiment

1. HUGS 2011 – Jefferson Laboratory • X GLUE Experiment Hussein Al Ghoul Department Of Physics Florida State University ᵠ

2. HUGS 2011 – Jefferson Laboratory • 12Gev upgrade Overview • Hall D • The physics behind Glue-X ᵠ

3. HUGS 2011 – Jefferson Laboratory But first! What are we looking for? ᵠ

4. HUGS 2011 – Jefferson Laboratory Exotic Mesons: Quantum numbers violate quark model. Non-Quark Model Mesons Glueballs: No valence quarks. Tetraquarks: Two quarks-antiquark pairs. Hybrid Mesons: A valence quark-antiquark and one or more gluons. ᵠ

5. HUGS 2011 – Jefferson Laboratory • Accelerator portion constructed on the framework of the existing CEBAF accelerator. • Perspective upgrades include: • Ten high-voltage cryomodules (maintaining the overall length of original design) • Ten new RF stations. • Double the refrigeration capacity. • Modifications to the magnets. • Modifications to the extraction system. • A tenth arc-beamline. • New beamline connected Hall D to the baseline accelerator. 12 Gev Upgrade 12 GeV upgrade, currently under construction (en.wikipedia.org) ᵠ

6. HUGS 2011 – Jefferson Laboratory Hall D Hall D will be located at the east end of the CEBAF north linac. Hall D will use the electron beam to produce a coherent bremsstrahlung beam and house a solenoid detector to carry out a program in gluonic spectroscopy to experimentally test current understanding of quark confinement. Architect’s rendering of Hall D complex (jlab.org) ᵠ

7. HUGS 2011 – Jefferson Laboratory GlueX Detector This detector is made up of: Liquid H target – 30cm long Solenoid: 2.24T Tracking (inside solenoid): Start counter Central Drift Chamber (CDC) Forward Drift Chamber (FDC) Calorimetry: Barrel Calorimeter (BCAL) Forward Calorimeter (FCAL) Time-of-Flight wall (ToF) Custom read-out and trigger GlueX detector (jlab.org) ᵠ

8. HUGS 2011 – Jefferson Laboratory Photon Tagger • The purpose of the photon tagging system is to provide a tagged flux of up to 108 Hz of linearly polarized photons from coherent bremsstrahlung in a thin (20μm), orientated, diamond crystal. Superconducting solenoid • The solenoid is the magnetic element selected to provide momentum analysis in the tracking chambers. The solenoid is a 73-inch warm bore super conducting (SC) device that produces a nominal maximum central field of 2.2 Tesla at 1800 Amps. Zisis Papandreou : THE GLUEX PROJECT AT JEFFERSON LAB Department of Physics, University of Regina, Regina, SK S4S0A2 Canada Target Low-power liquid hydrogen. Specifications: length: 30cm, diameter: 1 - 3cm Start Counter • The start counter will be providing a start signal for time of flight measurements and to identify the beam pulse associated with the observed event. It will be located close to the target in order to be independent of particle momenta and trajectories. ᵠ

9. HUGS 2011 – Jefferson Laboratory Central Drift Chamber • The purpose of the Central Drift Chamber (CDC) is to accurately measure (r, φ , z) coordinates along charged-particle tracks. (Particle tracking) Detector SideView Expanded (http://www.phys.uregina.ca) Calorimeter Barrel/ Forward The purpose of the barrel calorimeter (BCAL) and the forward calorimeter (FCAL) is the detection and energy determination of photons from the decays of the neutral π o , the η and other mesons decaying into photons. Forward Drift Chamber • The forward drift chambers (FDCs) include 4 separate packages of disk-shaped horizontal drift chambers to measure the momentum of all charged particles emerging from the target at angles of up to 30o relative to the photon beam line.(Particle tracking) Time-of-Flight • The purpose of the time-of-flight detector (TOF) is to serve as part of the particle identification system. ᵠ

10. HUGS 2011 – Jefferson Laboratory • Gluonic Excitations Flux tubes are formed between quarks due to the exchange of virtual gluons. As these two quarks move apart, the potential energy between them increases linearly with the distance separating them, and eventually becomes equal to the amount of energy required to form two new quarks. At that point the flux tube/string breaks , and two new quarks are formed and bound together through the same interaction form. Conventional mesons are formed when the flux tube is in the ground state. However, exciting this tube to the first excited state will result in exotic mesons. The physics behind GLUEX A Lattice QCD calculation showing that color field energy is localized in a "flux tube" between separated quarks. GlueX at Jefferson Lab will search for excitations of this flux tube.(Image by D. Leinweber)

11. HUGS 2011 – Jefferson Laboratory Flux Tubes Excitation

12. HUGS 2011 – Jefferson Laboratory A level diagram showing conventional nonets and expected masses of glueballs, hybrids, and meson-meson molecular thresholds. The vertical axis is in units of GeV/c2 . L refers to the angular momentum between the quarks and each box with JPC numbers refers to a nonet of mesons. The low-lying glueballs mix with conventional q¯q mesons, which complicates their identification. In contrast, hybrid mesons can possess JPC numbers not possible for q¯q and thus are easier to identify. Flux Tubes Excitation Zisis Papandreou : THE GLUEX PROJECT AT JEFFERSON LAB Department of Physics, University of Regina, Regina, SK S4S0A2 Canada ᵠ

13. HUGS 2011 – Jefferson Laboratory Flux Tubes Excitation cont’d http://www.learner.org Zisis Papandreou : THE GLUEX PROJECT AT JEFFERSON LAB Department of Physics, University of Regina, Regina, SK S4S0A2 Canada Left: With a π probe the incoming quarks have L = 0 and S = 0. The excited flux tube from the scattering results in hybrid mesons with non-exotic quantum numbers. Right: With a photon probe the incoming quarks have L = 0 and S = 1. When the flux tube is excited, hybrid mesons with exotic quantum numbers are possible. Here at Jlab, we will be searching for these exotic mesons within project GlueX. ᵠ

14. HUGS 2011 – Jefferson Laboratory Thank you!