\contentsline {section}{\numberline {1}EXECUTIVE SUMMARY}{1}
\contentsline {subsection}{\numberline {1.A}Physics Overview}{2}
\contentsline {subsubsection}{\numberline {1.A.1}Gluonic Excitations and the Origin of Quark Confinement}{3}
\contentsline {subsubsection}{\numberline {1.A.2}The Fundamental Structure of the Nuclear Building Blocks}{8}
\contentsline {paragraph}{Form Factors - Constraints on the Generalized Parton Distributions}{11}
\contentsline {paragraph}{Valence Quark Structure and Parton Distributions}{13}
\contentsline {paragraph}{The Generalized Parton Distributions as Accessed via Deeply Exclusive Reactions}{15}
\contentsline {paragraph}{Other Topics in Hadron Structure }{19}
\contentsline {subparagraph}{Transverse parton distributions}{19}
\contentsline {subparagraph}{The extended GDH integral and sum rule}{19}
\contentsline {subparagraph}{Duality: the transition from a hadronic to a quark-gluon description of Deep Inelastic Scattering}{21}
\contentsline {subsubsection}{\numberline {1.A.3}The Physics of Nuclei}{21}
\contentsline {paragraph}{The Short-Range Behavior of the $N-N$ Interaction and Its QCD Basis}{23}
\contentsline {subparagraph}{Color transparency.}{23}
\contentsline {subparagraph}{Learning about the $NN$ force by the measurement of the threshold $\psi $N cross section and by searching for $\psi $-nucleus bound states.}{23}
\contentsline {subparagraph}{Quark propagation through cold QCD matter: nuclear hadronization and transverse momentum broadening.}{24}
\contentsline {subparagraph}{Short-range correlations in nuclei: the nature of QCD at high density and the structure of cold, dense nuclear matter.}{24}
\contentsline {paragraph}{Identifying and Exploring the Transition from the Meson/Nucleon Description of Nuclei to the Underlying Quark and Gluon Description.}{25}
\contentsline {subparagraph}{The onset of scaling behavior in nuclear cross sections}{26}
\contentsline {subparagraph}{Helicity conservation in nuclear reactions}{26}
\contentsline {subparagraph}{The charged pion form factor}{28}
\contentsline {subparagraph}{Pion photoproduction from the nucleon and in the nuclear medium}{28}
\contentsline {subsubsection}{\numberline {1.A.4}Symmetry Tests in Nuclear Physics}{30}
\contentsline {paragraph}{Standard Model Tests}{30}
\contentsline {paragraph}{Properties of Light Pseudoscalar Mesons via the Primakoff Effect}{31}
\contentsline {subsection}{\numberline {1.B}Upgrade Project Summary}{33}
\contentsline {subsubsection}{\numberline {1.B.1}The Accelerator}{34}
\contentsline {subsubsection}{\numberline {1.B.2}The Experimental Equipment}{36}
\contentsline {paragraph}{Hall\nobreakspace {}A and the Medium Acceptance Device (MAD)}{36}
\contentsline {paragraph}{Hall\nobreakspace {}B Upgrade and CLAS$^{++}$.}{38}
\contentsline {paragraph}{Hall\nobreakspace {}C and the Super High Momentum Spectrometer (SHMS)}{42}
\contentsline {paragraph}{Hall\nobreakspace {}D and the GlueX Experiment}{45}
\contentsline {section}{\numberline {2}THE SCIENCE DRIVING THE 12\nobreakspace {}GeV UPGRADE OF CEBAF}{49}
\contentsline {subsection}{\numberline {2.A}Gluonic Excitations and the Origin of Quark Confinement}{49}
\contentsline {subsubsection}{\numberline {2.A.1}Introduction}{49}
\contentsline {subsubsection}{\numberline {2.A.2}Conventional light mesons}{52}
\contentsline {subsubsection}{\numberline {2.A.3}Gluonic excitations and confinement}{55}
\contentsline {subsubsection}{\numberline {2.A.4}Observation of gluonic excitations}{57}
\contentsline {paragraph}{Glueballs}{57}
\contentsline {paragraph}{Exotic hybrid mesons}{58}
\contentsline {subsubsection}{\numberline {2.A.5}Photoproduction of exotic hybrids}{61}
\contentsline {paragraph}{Why photoproduction?}{61}
\contentsline {paragraph}{Current photoproduction data}{62}
\contentsline {subsubsection}{\numberline {2.A.6}Complementarity with other searches}{64}
\contentsline {subsubsection}{\numberline {2.A.7}Production and analysis of hybrid mesons}{65}
\contentsline {paragraph}{Kinematics}{65}
\contentsline {paragraph}{PWA requirements}{66}
\contentsline {paragraph}{Linear polarization of the beam}{67}
\contentsline {subparagraph}{Linear and circular polarization}{67}
\contentsline {subparagraph}{Linear polarization and statistics}{67}
\contentsline {subparagraph}{Linear polarization and production mechanism}{68}
\contentsline {subparagraph}{Linear polarization as an exotics filter}{68}
\contentsline {subsection}{\numberline {2.B}The Fundamental Structure of the Nuclear Building Blocks}{69}
\contentsline {subsubsection}{\numberline {2.B.1}Introduction}{69}
\contentsline {subsubsection}{\numberline {2.B.2}Form Factors -- Constraints on the Generalized Parton Distributions}{73}
\contentsline {paragraph}{Form Factors at Large Momentum Transfer}{76}
\contentsline {subparagraph}{Form Factors and Generalized Parton Distributions}{76}
\contentsline {subparagraph}{The Charged Pion Form Factor}{79}
\contentsline {subparagraph}{Baryon Form Factors and GPDs}{80}
\contentsline {subparagraph}{pQCD - Constituent Scaling, Helicity Conservation}{89}
\contentsline {paragraph}{Summary}{92}
\contentsline {subsubsection}{\numberline {2.B.3}Valence Quark Structure and Parton Distributions}{92}
\contentsline {paragraph}{Theoretical predictions for large-$x$ distributions}{95}
\contentsline {paragraph}{The structure of the free neutron}{97}
\contentsline {subparagraph}{``Tagged'' neutron structure function}{98}
\contentsline {subparagraph}{Deep inelastic scattering from $A=3$ nuclei}{98}
\contentsline {subparagraph}{Longitudinal--transverse separation}{99}
\contentsline {subparagraph}{Moments of structure functions}{101}
\contentsline {paragraph}{The spin structure of the nucleon}{101}
\contentsline {subparagraph}{Neutron spin structure functions}{101}
\contentsline {paragraph}{Higher-twist effects}{106}
\contentsline {paragraph}{Semi-inclusive scattering}{108}
\contentsline {subsubsection}{\numberline {2.B.4}The Generalized Parton Distributions as Accessed via Deeply Exclusive Scattering}{113}
\contentsline {paragraph}{The Physics of the Generalized Parton Distributions}{113}
\contentsline {subparagraph}{Spin Structure of the Nucleon}{114}
\contentsline {subparagraph}{Gravitational Form Factors}{116}
\contentsline {subparagraph}{``Tomographic'' Images of the Nucleon}{116}
\contentsline {subparagraph}{Modeling GPDs}{118}
\contentsline {paragraph}{Probing GPDs Through 12\nobreakspace {}GeV Upgrade}{118}
\contentsline {subparagraph}{DVCS at JLab with 12\nobreakspace {}GeV Electrons}{121}
\contentsline {subparagraph}{Deeply Virtual Meson Production at JLab with 12\nobreakspace {}GeV Electrons}{130}
\contentsline {subparagraph}{From Observables to GPDs}{137}
\contentsline {subsubsection}{\numberline {2.B.5}Other Topics in Hadron Structure}{139}
\contentsline {paragraph}{Transverse parton distributions}{139}
\contentsline {paragraph}{The extended GDH integral and sum rule}{144}
\contentsline {paragraph}{Quark-Hadron Duality}{146}
\contentsline {subsection}{\numberline {2.C}The Physics of Nuclei}{150}
\contentsline {subsubsection}{\numberline {2.C.1}Hadron Structure in the Nuclear Medium}{152}
\contentsline {paragraph}{Nuclear Matter at High Densities}{154}
\contentsline {subparagraph}{Modification to Hadron Structure in Nuclei}{155}
\contentsline {subparagraph}{High-Density Configurations in Nuclei}{156}
\contentsline {paragraph}{Color Transparency}{159}
\contentsline {subparagraph}{Color Transparency in A(e,e'p)}{160}
\contentsline {subparagraph}{Color Transparency in Few-Body Systems}{161}
\contentsline {subparagraph}{Color Transparency in Meson Production}{161}
\contentsline {paragraph}{$J/\psi $ Photoproduction Near Threshold}{164}
\contentsline {paragraph}{Space-Time Characteristics of Hadronization}{167}
\contentsline {paragraph}{Transverse Momentum Broadening}{170}
\contentsline {subsubsection}{\numberline {2.C.2}Short-Range Correlations in Nuclei}{172}
\contentsline {paragraph}{Electrodisintegration of the Deuteron}{172}
\contentsline {paragraph}{$A(e,e'pN)$ Processes}{175}
\contentsline {paragraph}{Inclusive $A(e,e')X$ Processes}{177}
\contentsline {subsubsection}{\numberline {2.C.3}The Parton-Hadron Transition in Nuclei}{179}
\contentsline {paragraph}{Elastic Form Factor of Charged Pion}{180}
\contentsline {paragraph}{Few-Body Form Factors}{181}
\contentsline {paragraph}{Deuteron Photodisintegration}{184}
\contentsline {paragraph}{Nucleon Photopion Production}{186}
\contentsline {paragraph}{Pion Photoproduction in the Nuclear Medium}{188}
\contentsline {subsection}{\numberline {2.D}Symmetry Tests in Nuclear Physics}{190}
\contentsline {subsubsection}{\numberline {2.D.1}Standard Model Tests}{190}
\contentsline {subsubsection}{\numberline {2.D.2}Properties of Light Pseudoscalar Mesons via the Primakoff Effect}{201}
\contentsline {section}{\numberline {3}EXPERIMENTAL EQUIPMENT FOR THE 12\nobreakspace {}GeV UPGRADE}{214}
\contentsline {subsection}{\numberline {3.A}Hall\nobreakspace {}A and the Medium Acceptance Device (MAD)}{214}
\contentsline {subsubsection}{\numberline {3.A.1}Design Characteristics of the MAD Spectrometer}{216}
\contentsline {subsubsection}{\numberline {3.A.2}Optical Characteristics of the MAD Spectrometer}{226}
\contentsline {subsubsection}{\numberline {3.A.3}Simulations of the MAD Spectrometer}{230}
\contentsline {subsubsection}{\numberline {3.A.4}MAD Spectrometer Detector Systems}{231}
\contentsline {paragraph}{Scintillators}{232}
\contentsline {paragraph}{Drift Chambers}{234}
\contentsline {paragraph}{Gas \v {C}erenkov Counter}{235}
\contentsline {paragraph}{Aerogel \v {C}erenkov Counters}{236}
\contentsline {paragraph}{Electromagnetic Calorimeter}{239}
\contentsline {paragraph}{Focal Plane Proton Polarimeter}{239}
\contentsline {paragraph}{Trigger Electronics}{240}
\contentsline {paragraph}{Data Acquisition}{241}
\contentsline {subsubsection}{\numberline {3.A.5}High Performance Calorimeter}{242}
\contentsline {subsubsection}{\numberline {3.A.6}The Hall\nobreakspace {}A Beam Line}{244}
\contentsline {subsection}{\numberline {3.B}Hall\nobreakspace {}B Upgrade and the CLAS$^{++}$ Detector}{246}
\contentsline {subsubsection}{\numberline {3.B.1}Overview}{246}
\contentsline {subsubsection}{\numberline {3.B.2}CLAS Torus Magnet}{248}
\contentsline {subsubsection}{\numberline {3.B.3}Central Detector}{249}
\contentsline {paragraph}{Superconducting Solenoid Magnet}{250}
\contentsline {subparagraph}{Magnet Design}{250}
\contentsline {paragraph}{Central Electromagnetic Calorimeter}{252}
\contentsline {subparagraph}{Overview}{252}
\contentsline {subparagraph}{Requirements}{252}
\contentsline {subparagraph}{Scintillating Fiber/Tungsten Powder Calorimeter Design}{252}
\contentsline {subparagraph}{Expected Performance}{253}
\contentsline {subparagraph}{Prototyping and Simulations}{255}
\contentsline {paragraph}{Central Time-of-Flight System}{256}
\contentsline {subparagraph}{Expected Rates}{256}
\contentsline {subparagraph}{Options}{258}
\contentsline {paragraph}{Central Tracker}{258}
\contentsline {paragraph}{Silicon Strip Detector}{260}
\contentsline {subparagraph}{Instrumentation}{261}
\contentsline {subparagraph}{Prototyping}{262}
\contentsline {paragraph}{Forward Detector}{262}
\contentsline {subparagraph}{Overview}{262}
\contentsline {subparagraph}{High Threshold \v {C}erenkov Counter (HTCC)}{263}
\contentsline {subparagraph}{Forward Tracking Chambers}{265}
\contentsline {subparagraph}{Low Threshold \v {C}erenkov Counter}{267}
\contentsline {subparagraph}{Outer TOF System}{267}
\contentsline {subparagraph}{Inner Calorimeter}{270}
\contentsline {subparagraph}{Forward Angle Calorimeter}{271}
\contentsline {subparagraph}{Pre-shower calorimeter}{271}
\contentsline {subsubsection}{\numberline {3.B.4}Polarized Target Operation in CLAS$^{++}$}{274}
\contentsline {paragraph}{Longitudinally polarized Target in Solenoid Magnet}{274}
\contentsline {paragraph}{Transversely Polarized Target.}{275}
\contentsline {subsubsection}{\numberline {3.B.5}Beam Line}{275}
\contentsline {paragraph}{Faraday Cup}{275}
\contentsline {paragraph}{M\o ller Polarimeter}{275}
\contentsline {paragraph}{Magnetic Chicane}{276}
\contentsline {paragraph}{Beam raster magnets}{276}
\contentsline {subsubsection}{\numberline {3.B.6}Data Acquisition System and Trigger}{276}
\contentsline {paragraph}{Design criteria for the system}{276}
\contentsline {paragraph}{System upgrade}{276}
\contentsline {subsubsection}{\numberline {3.B.7}Event Reconstruction and Offline Computing}{277}
\contentsline {paragraph}{Data Reduction and Online Event Reconstruction}{278}
\contentsline {subsection}{\numberline {3.C}Hall\nobreakspace {}C and the Super High Momentum Spectrometer (SHMS)}{278}
\contentsline {subsubsection}{\numberline {3.C.1}Overview}{278}
\contentsline {subsubsection}{\numberline {3.C.2}The High-Momentum Spectrometer}{279}
\contentsline {subsubsection}{\numberline {3.C.3}The Super-High-Momentum Spectrometer}{282}
\contentsline {paragraph}{Overview}{282}
\contentsline {paragraph}{The SHMS Magnets and Structural Design}{282}
\contentsline {subparagraph}{General}{282}
\contentsline {subparagraph}{Q1 at 8.6\nobreakspace {}T/m}{282}
\contentsline {subparagraph}{QD30 Superconducting Magnet for the SHMS }{286}
\contentsline {subparagraph}{Magnet DC Power and Energy Dump System}{287}
\contentsline {subparagraph}{Magnet Control System}{291}
\contentsline {subparagraph}{Support Structure}{291}
\contentsline {subparagraph}{Spectrometer Motion System}{291}
\contentsline {subparagraph}{Shield House}{293}
\contentsline {subparagraph}{SHMS Cryogenic System}{293}
\contentsline {subparagraph}{SHMS Vacuum Systems}{295}
\contentsline {paragraph}{SHMS Optics and Monte Carlo}{295}
\contentsline {subparagraph}{SHMS Optics Design}{295}
\contentsline {subparagraph}{COSY magnet model}{297}
\contentsline {subparagraph}{LSA tune}{299}
\contentsline {subparagraph}{SHMS model in the `physics' Monte Carlo}{300}
\contentsline {paragraph}{SHMS Performance (Resolution/Acceptance)}{302}
\contentsline {paragraph}{SHMS Detector Systems}{303}
\contentsline {subparagraph}{Wire Chambers}{309}
\contentsline {subparagraph}{Quartz \v {C}erenkov Hodoscope}{309}
\contentsline {subparagraph}{Particle Identification}{314}
\contentsline {subparagraph}{Focal Plane Polarimeter}{324}
\contentsline {subparagraph}{Trigger, Data Acquisition, and On-line Computing}{326}
\contentsline {subparagraph}{Stand-Alone (Third-Arm) Calorimeter}{328}
\contentsline {subsection}{\numberline {3.D}Hall D and the GlueX Experiment}{328}
\contentsline {subsubsection}{\numberline {3.D.1}Introduction}{328}
\contentsline {subsubsection}{\numberline {3.D.2}The Photon Beam and Polarization}{329}
\contentsline {paragraph}{The Photon Tagger and Beam Collimation}{329}
\contentsline {paragraph}{Polarization via Coherent Bremsstrahlung}{331}
\contentsline {subsubsection}{\numberline {3.D.3}The {\textsc {GlueX}}{} Detector}{333}
\contentsline {paragraph}{The Super-conducting Solenoid}{333}
\contentsline {paragraph}{Particle Tracking and Particle Identification}{334}
\contentsline {subparagraph}{The Vertex Detector}{334}
\contentsline {subparagraph}{The Cylindrical Drift Chamber}{335}
\contentsline {subparagraph}{The Forward Drift Chambers}{336}
\contentsline {paragraph}{Electromagnetic Calorimetry}{337}
\contentsline {subparagraph}{The Forward Calorimeter}{337}
\contentsline {subparagraph}{The Barrel Calorimeter}{337}
\contentsline {subparagraph}{The Upstream Photon Veto}{340}
\contentsline {paragraph}{Charged Particle Identification}{341}
\contentsline {subparagraph}{The Time-of-Flight System}{341}
\contentsline {subparagraph}{The \v {C}erenkov Detector}{343}
\contentsline {paragraph}{Sub-system Installation and Integration}{344}
\contentsline {subsubsection}{\numberline {3.D.4}Rates, Electronics, Trigger and Data Acquisition}{344}
\contentsline {subsubsection}{\numberline {3.D.5}Computing and Partial Wave Analysis}{348}
\contentsline {subsubsection}{\numberline {3.D.6}Summary}{353}
\contentsline {subsection}{\numberline {3.E}Experiment-Specific Equipment}{353}
\contentsline {subsubsection}{\numberline {3.E.1}Properties of Light Pseudoscalar Mesons via the Primakoff Effect}{353}
\contentsline {section}{\numberline {}{REFERENCES}}{363}
\contentsline {section}{\numberline {}{FIGURES}}{392}
\contentsline {section}{\numberline {}{TABLES}}{404}
\contentsline {section}{\numberline {}{CONTRIBUTORS TO THE pCDR}}{406}