The Italian Collaboration at Jefferson Lab

1. INFN is participating to the scientific activity at Jefferson Lab since 1991 The collaboration was initially formed by ~25 scientists of the INFN Units of Bari, Genova and the Frascati National Laboratory and has been contributing to the 6 GeV program in Hall A and Hall B The Italian Collaboration at Jefferson Lab Presently, the Italian Collaboration includes 80 scientists among experimentalists and theorists from 16 INFN Units and National Laboratories, who are participating to the 6 GeV running and 12 GeV Upgrade INFN Units: Sezione di Alessandria Sezione di Bari Sezione di Cagliari Sezione di Catania Sezione di Ferrara Sezione di Genova Istituto Superiore di Sanità Laboratori Nazionali di Frascati Sezione di Milano Bicocca Sezione di Pavia Sezione di Perugia Sezione di Pisa Sezione di Roma I Sezione di Roma II Sezione di Torino Sezione di Trento

2. The 12 GeV upgrade The Italian Collaboration is participating to the upgrade of the Laboratory, contributing to the development of the physics program and to the design and construction of new equipment for Hall A and Hall B The main physics topics of the program proposed by Italian scientists are: • Structure of the Nucleon: • P. Rossi, E12-07-107: “Studies of Spin-Orbit Correlations with Longitudinally Polarized Target” • E. Cisbani, E12-07-109: “Large Acceptance Proton Form Factor Ratio Measurements at 13 and 15 (GeV/c)2 Using Recoil Polarization Method” • M. Mirazita, E12-09-007: “Studies of partonic distributions using semi-inclusive production of kaons” • M. Contalbrigo, E12-09-008: “Studies of the Boer-Mulders Asymmetry in Kaon Electroproduction with Hydrogen and Deuterium Targets” • E. Cisbani, P. Rossi, E12-09-009: “Studies of Spin-Orbit Correlations in Kaon Electroproduction in DIS with Polarized Hydrogen and Deuterium Targets” • E. Cisbani, E12-09-018: “Measurement of the Semi-Inclusive pi and kappa electro-production in DIS regime from transversely polarized 3He target with the SBS&BB spectrometers in Hall A” • R. De Vita, M. Mirazita,LOI-09-001:“Deeply virtual Compton scattering on the neutron with CLAS at 11 GeV” • Hadron Spectroscopy: • M. Battaglieri, R. De Vita, LOI12-10-001: “Spectroscopy with Low Q2 electro-scattering in CLAS” Hall A CLAS12 Hardware contributions to the Jefferson Lab upgrade involve the Super-Big-Byte Spectrometer for Hall A and the Forward Tagging facility, the RICH detector and the Central Neutron Detector for CLAS12 in Hall B Hall B

3. ADC and control VME64x module Super-Big-Byte Spectrometer in Hall A • New Spectrometer for Hall A: • High Luminosity (~1039) • Forward angle (down to 7 degree) • Large acceptance (for Hall A) • Equipment flexibility and for optimal reuse in different experiments • Italian responsibility on the primary tracker: • Large area GEM chambers for tracking with resolution ~70 mm • Able to support 0.5 MHz/cm2 background hits • Use small silicon planes to improve reconstruction • Development of the electronics for all trackers for more than 100000 channels Front End Card Prototype Beam Test

4. Electron energy/momentum Photon energy (n=E-E') Polarization e-1 ~ 1 + n2/2EE' Calorimeter + Tracking + Veto Electron angles Q2= 4 E E' sin2J/2 j polarization plane To separate photons from electrons and to define the trigger The Forward Tagging Facility for CLAS12:Quasi-real electroproduction at Low Q2 A tagged photon beam will open new possibility for high quality physics beyond the already approved program • Exotic meson search • Hadron spectroscopy • J/y threshold production • ... • Electron scattering at “0” degrees (2° - 5°)  low Q2 virtual photon  real photon • Photon tagged by detecting the scattered • electron at low angles • Quasi-real photons are linearly polarized  Polarization ~ 65% - 20% • High Equivalent Luminosity  Ng ~ 5 x107 g/s • (unique opportunity to run thin gas target!) Institutions: Edinburgh U., Glasgow U., INFN (project coordination), JLab, NSU, Orsay, Saclay • Complementary to Hall-D (GLUEX) • Exploits the unique PID & resolution of CLAS12

5. Location of NEW RICH Detector The RICH Detector for CLAS12 • Measurements with identified kaons can provide important information on several hot topics in hadronic physics: • - Study of the nucleon tomography and the quark orbital angular momentum (GPDs and TMDs) • - Strange distribution and fragmentation functions • - Quark hadronization in the nuclear medium • - Hadron spectroscopy and exotic mesons • The Italian Groups(project coordination)in collaboration with the Argonne National Lab and the University of Glasgow have proposed the construction of a RICH Detector for CLAS12 in Hall B to improve the hadron PID, in particular the pion-kaon separation, in the 3-8 GeV/c momentum range. The RICH detector, would replace the CLAS12 Low Threshold Cherenkov Counter (LTCC). • The Italian Groups are responsible for the R&D of the detector • software simulation and pattern recognition • tests of photon detectors (SiPM, MAPMT) • construction of a prototype • Challenging project due to: • - Large Detector area(several m2) • - Position in front of the TOF which requires small material budget • Preliminary results from simulations show that a 5-6-K separation at 8 GeV/c is achievable with an aerogel proximity focusing RICH and detecting the visible part of the Cherenkov light.

6. Central Tracker CTOF CND The Central Neutron Detector for CLAS12 • The study of Generalized Parton Distributions (GPDs) is one of the leading programs of the Jefferson Lab Upgrade: GPDs provide information on the 3D quark/gluon structure of the nucleon and can be accessed by studying exclusive reactions as Deeply Virtual Compton Scattering (DVCS) • Measurement of cross section and polarization observables on proton and neutron targets are necessary to access GPDs • The Italian Groups in collaboration with IPN-Orsay and the University of Glasgow have proposed the construction of Central Neutron Detector (CND) as upgrade of the CLAS12 detector in Hall B • The CND, consisting of a barrel of plastic scintillator, will detect and identify neutrons with p=0.2-1 GeV/c and q=40-140 deg. using the time-of-flight technique, allowing to study DVCS on the neutron • R&D to indentify the optimal technical solutions is presently in progress • The Italian Groups are responsible for the test of Silicon Photomultipliers for the readout of the plastic scintillator • Central Neutron Detector: • barrel of plastic scintillator paddles located between the CTOF and the 5-Tesla solenoid • Dimensions: OR=39cm, IR= 28cm, L = 66 cm

7. Scientific Activity at 6 GeV The scientific activity of the Italian Groups is subdivided into 4 main fields that belong to the science mainstreams of the Jefferson Lab physics program • Hadron Spectroscopy: • Study of the Nucleon Excitation Spectrum and Search for Missing Resonances • Study of the Meson Spectrum • Search for Exotics • The Structure of the Nucleon: • Nucleon Form Factors • Nucleon Structure Functions from Inclusive and Semi-Inclusive Processes • Study of the Spin Structure of the Nucleon • The Study of the Transition between Hadronic and Partonic Degrees of Freedom: • Vector Meson Production at Large Momentum Transfer • Deuteron Photodisintegration • The Nuclear Structure: • The Neutron Skin of 208Pb • Hypernuclear Spectroscopy • Study of N-N Correlations

8. Scientific Activity at 6 GeV & Experiments with Italian Leadership • Hadron Spectroscopy: • M. Taiuti, E91-002: “The study of Excited Baryons at High Momentum Transfer with the CLAS Spectrometer” • S. Frullani, E91-011: “Investigation of the N->Δ Transition via Polarization Observables in Hall A” • M. Ripani, E93-006: “Two Pion Decay of Electroproduced Baryon Resonances” • M. Anghinolfi, E93-036: “Measurement of Single Pion Electroproduction from the Proton with Polarized Beam and Polarized Target Using CLAS” • S. Frullani, M. Iodice, E98-108: “Electroproduction of Kaons up to Q2=3 (GeV/c) 2” • M. Taiuti, E-99-107: “N* Excitations at High Q2 in the pp0 and n p+ Channels” • M. Ripani, E-99-108: “N* Excitations at High Q2 in the Two-Pion Channel” • M. Battaglieri, R. De Vita, E-04-017: “Study of Pentaquark States in Photoproduction off Protons” • M. Battaglieri, R. De Vita, E-04-021: “Spectroscopy of Exotic Baryons with CLAS: Search for Ground and Excited States” • The Structure of the Nucleon: • M. Taiuti, E-93-009: “The Polarized Structure Function G1n and the Q2 Dependence of the Gerasimov-Drell-Hearn Sum Rule for the Neutron” • F. Garibaldi, E97-110: “The GDH Rule and the Spin Structure of 3He and the Neutron Using Nearly Real Photons” • M. Battaglieri, R. De Vita, M. Ripani, E-03-006: “The GDH Sum Rule with nearly real photons and the proton g1 structure function at low momentum transfer” • E. Cisbani, E06-010: “Measurement of Single Target-Spin Asymmetry in Semi-Inclusive Pion Electroproduction on a Transversely Polarized 3He Target” • P. Rossi, E-08-015: “Transverse spin effects in SIDIS at 6 GeV with transversely polarized target using the CLAS Detector” • The Study of the Transition between Hadronic and Partonic Degrees of Freedom: • E. De Sanctis, P. Rossi, E-93-017: “Study of γd -> pn and γd -> pΔ0 Reactions for Small Momentum Transfers” • M. Anghinolfi, M. Battaglieri, E-93-031: “Photoproduction of Vector Mesons at High t” • The Nuclear Structure: • N. Bianchi, V. Muccifora, E-93-019: “Photoabsorption and Photofission of Nuclei” • P. Corvisiero, E-93-044: “Photoreactions on 3He” • F. Garibaldi, S. Frullani, E94-107: “High Resolution Hypernuclear 1p shell Spectroscopy” • G.M.Urciuoli, E06-002: “PREX (Lead Radius Parity Experiment)” • G.M.Urciuoli, E06-007: “Impulse Approximation limitations to the (e,e'p) on 208Pb: Identifying Correlations and Relativistic Effects in the Nuclear Medium” • F. Garibaldi, M. Iodice, E07-012: “The Angular Dependence of 16O(e,e'K)16N_lambda and H(e,e'K)”

9. Physics Publications • Italian Collaborators are among the leading authors of 30 physics papers, published in referred journals as • Physical Review Letters (17) • Physical Review C (6) • Physical Review D (4) • Nuclear Physics (2) • Physics Letters (1) • Presently 7 of these papers are listed as TopCite • These publications discuss physics results obtained in the 4 scientific areas • Hadron Spectroscopy: • 13 papers • 8 PRL + 2 PRC + 2 PRD + 1 PLB + 1 NPA • 4 TopCite • The Structure of the Nucleon: • 6 papers • 3 PRL + 1 PRC + 2 PRD • 2 TopCite • The Study of the Transition between Hadronic and Partonic Degrees of Freedom: • 5 papers • 4 PRL + 1 PRC • 1 TopCite • The Nuclear Structure: • 5 paper • 2 PRL + 3 NPA

10. RICH Detector hadron arm electron arm septum magnets Experimental Equipment for Hall A ~100 k$ ~800 k$ ~1.1 M$ Important contributions to base equipment and specific apparatus ~200 k$ Septum magnets for very low angle electron detection ~200 k$ Waterfall target for measurements on 16O

11. Hall A Technical Papers • The CO2 gas Cherenkov detectors for the Jefferson Lab Hall A spectrometers • Iodice, M. and Cisbani, E. and Colilli, S. et al., NIM A 411 (1998), 223-237. • Performances of the aerogel threshold Cherenkov counter for the Jefferson Lab Hall A spectrometers in the 1-4 GeV/c momentum range • Perrino, R. and Lagamba, L. and Cisbani, E. and Colilli, S. et al., NIM A 457 (2001), 457-571. • Silica aerogel threshold Cherenkov counters for the JLab Hall A spectrometers: improvements and proposed modifications • Lagamba, L. and Cisbani, E. and Colilli, S. et al., NIM A 471 (2001), 325-332. • Light-weight spherical mirrors for Cherenkov detectors • Cisbani, E. and Colilli, S. et al., NIM A, 496 (2003), 305-314. • A proximity focusing RICH detector for kaon physics at Jefferson lab Hall A • Garibaldi, F. et al., NIM A 502 (2003), 117-122. • Quantum efficiency measurement system for large area CsI photodetectors • Cusanno, F. and Cisbani, E. and Colilli et al., NIM A 502 (2003), 251-255. • A RICH detector for strangeness physics in Hall A at Jefferson Lab • Cusanno, F. and Garibaldi, F. and Cisbani, E. and Colilli, et al., NIM A 525 (2004), 163-167. • Performance and results of the RICH detector for kaon physics in Hall A at Jefferson Lab • Iodice, M. and Cisbani, E. and Colilli, S. and Cusanno et al., NIM A 553 (2005), 231-236. • Upgrade of the proximity focusing RICH at JLab • Cisbani, E. and Colilli, S. and Cusanno, F. and Fratoni, R. and Frullani, S. and Garibaldi, F. and Giuliani, F. and Gricia, M. and Lucentini, M. and Santavenere, F. and Urciuoli, G. M. and Iodice, M. and Argentieri, A. and Cataldo, G. De and De Leo, R. and Lagamba, L. and Marrone, S. and Nappi, E. and Camsonne, A. and Kross, B. and Michaels, R. and Reitz, B. and Segal, J. and Wojtsekhowski, B. and Zorn, C. and Monno, E. and Breuer, H., NIMA 595 (2008), 44-46. • Performace of the two aerogel Cherenkov detectors of the JLab Hall A hadron spectrometer • Marrone, S. and Wojtsekhowski, B. and Acha, A. and Cisbani, E. and Coman, M. and Cusanno, F. et al., Il Nuovo Cimento 124 B (2009), 99-114. • A c2 test used for particle identification with the Hall A RICH detector at JLab • Urciuoli, G. M. and Cisbani, E. and Cusanno, F. and De Leo, R. and Bari, D. Di and Frullani, S. and Garibaldi, F. and Iodice, M. and Lagamba, L. and LeRose, J. J. and Markowitz, P. and Marrone, S. and Reitz, B. , NIM A 612 (2009), 56-58.

12. Experimental Equipment for Hall B Cerenkov Counter for low-Q2 ~300K$ Polarized Target for electron beam ~700K$ Important contributions to base equipment and specific apparatus Large Angle Calorimeterfor detection of neutrals ~4M$ Upgrade of the Bonus Detector Electronics ~45K$ Start Counter for photon beam ~47K$ Tagger Electronics Upgrade ~70K$

13. HD-ice: polarized frozen spin HD target • A new class of polarized target of high dilution factor is made of solid Deuterium-Hydride • Longitudinal and Transverse Polarizations: > 60% • Relaxation time: > 1 year • Polarization procedure  3 months • Data taking:  months Target cell • INFN contribution: • dilution refrigerator • Raman analysis of HD gas • NMR for polarization monitoring Target Transfer Comparison of signal over background ratio: HD versus conventional polarized target INFN Dilution Refrigerator In-beam cryostat

14. Hall B Technical Papers Performances of the optical readout system for the large angle electromagnetic shower calorimeter for CLAS M. Taiuti, M. Anghinolfi, N. Bianchi, G.P. Capitani, P. Corvisiero, E. De Sanctis, P. Levi Sandri, V.I. Mokeev, V. Muccifora, M. Olcese, E. Polli, G. Ricco, A.R. Reolon, M. Ripani, P. Rossi, A. Rottura, M. Sanzone, A. Zucchiatti. Nucl. Instr. & Meth. A357 (1995), 344-349. Measurement of the response of long plastic scintillator bars for the large angle electromagnetic shower calorimeter for CLAS M. Taiuti, P. Rossi, R. Morandotti, M. Anghinolfi, H. Avakian, M .Battaglieri, N. Bianchi, P. Corvisiero, E. De Sanctis, V.Giourjian, P. Levi Sandri, A.Longhi, V.I. Mokeev, V. Muccifora, M. Olcese, E. Polli, A.R. Reolon, G. Ricco, M. Ripani, M. Sanzone, A. Zucchiatti. Nucl. Instr. & Meth. A370 (1996), 429-434. Peformance of the new plastic scintillator NE110A for the CLAS large angle calorimeter P.Rossi, E.Polli, M.Albicocco, H.Avakian, N. Bianchi, G.P.Capitani, A. Deppman, E. De Sanctis, V.Giourjian, P. Levi Sandri, S. Mansanta, M.Mirazita, V. Muccifora, A.R. Reolon, M. Taiuti, A. Rottura, M. Anghinolfi, M.Battaglieri, P.Corvisiero, A. Longhi, V.I. Mokeev, M. Olcese, G. Ricco, M. Ripani, M. Sanzone, A. Zucchiatti, R.Morandotti. Nucl. Instr. & Meth. A381 (1996), 32-38. Choice and test of the photomultipliers for the Large Angle Electromagnetic Shower Calorimeter for the CLAS detector at CEBAF M. Ripani, M. Anghinolfi, H.Avakian, M.Battaglieri, M. Castoldi, P.Corvisiero, A. Deppman, V.Giourjian, E. Golovach, A. Longhi, V.I. Mokeev, F. Ronchetti, P.Rossi, , A. Rottura , V. Sapunenko, E. Shirokov, M. Taiuti. Nucl. Instr. & Meth. A 406 (1998), 403-410. Response to cosmic rays of the Large Angle Electromagnetic Shower Calorimeter of the CLAS detector M. Anghinolfi, M.Battaglieri, P.Corvisiero , R. De Vita, E. Golovach, A. Longhi, V.I. Mokeev, G. Ricco, M. Ripani, V. Sapunenko, M. Taiuti, N. Bianchi, E. De Sanctis, V.Giourjian, V. Muccifora, M. Mirazita, E. Polli, A.R. Reolon, F. Ronchetti, P.Rossi. Nucl. Instr. and Meth. A 447 (2000), 424-431. The CLAS Electromagnetic Calorimeter at Large Angle M. Anghinolfi, H. Avakian, M.Battaglieri, N. Bianchi, P.Corvisiero, R. De Vita, E. Golovach, V.Gyuriyan, M. Mirazita, V. Mokeev, V. Muccifora, Osipenko, E. Polli, G. Ricco, M. Ripani, F. Ronchetti, P.Rossi,V. Sapunenko, M. Taiuti. Nucl. Instr. & Meth. A537 (2005), 562, LANL-preprint nucl-ex/0403041. A new highly segmented start counter for the CLAS detector Y. G. Sharabian, M.Battaglieri, V. Burkert, R. De Vita, L. Elouadrhiri, L. Guo, D. Kashy, V. Kubarovsky, G.S. Mutchler, M. Ostrick, M. Ripani, P.Rossi, A. Rottura, E. Pasyuk, D. Weygand. Nucl. Instr. and Meth. A 556 (2006), 246-258.

15. Service Work Italian Collaborators have been covering relevant roles in the Jefferson Lab community, as member of committees and chair of working groups and collaborations: • R. De Vita, Member CLAS12 Steering Committee • M. Ripani, CLAS Collaboration Chair, 2009-today • R. De Vita, Secretary of the CLAS Speakers Committee, 2006-today • M. Battaglieri, Chair of the CLAS Speakers Committee, 2005-today • P. Rossi, Chair of the CLAS Service Work Committee, 2004-today • P. Rossi, Member of the JLab Program Advisory Committee, 2010 • M. Ripani, Member of the JLab Program Advisory Committee, 2006-2009 • R. De Vita, Member of the JLab User Group Board of Directors, 2005-2007 • R. De Vita, Member of the CLAS Speakers Committee, 2003-2006 • N. Bianchi, Member of the JLab Program Advisory Committee, 2003-2005 • M. Battaglieri, Member of the CLAS Speakers Committee, 2001-2005 • P. Rossi, Member of the CLAS Service Work Committee, 2003-2004 • M. Taiuti, Chair of the CLAS Structure of the Nucleon Working Group, 2001-2004 • M. Taiuti, Member of the JLab Program Advisory Committee, 2000-2002 • E. De Sanctis, Member of the JLab Program Advisory Committee, 1997-1999 • G. Ricco, Member of the JLab Program Advisory Committee, 1995-1996

16. Conference and Workshops • International Workshop on Exclusive reactions at high momentum transfer, Marciana Marina - Italy, June 24-26, 1993 • GDH2002, “2nd Symposium on the Gerasimov-Drell-Hearn Sum Rule and the Spin Structure of the Nucleon”, Genova - Italy, July 3-6 2002 • Jefferson Lab at 12 GeV, “Workshop on the Perspectives in Hadronic Physics at JLab”, Genova – Italy, February 2008 • CLAS12 European Workshop, “First European Workshop on the Physics Program and equipment of the CLAS12 experiment at Jefferson Lab”, Genova – Italy, 26-28 February 2008 • 2nd JSPS Core-to-core seminar, “Workshop on Strangeness Nuclear Physics by Electron Beams”, ISS-Rome 15-16 Dec 2009 • PSHP2010, “Probing Strangeness in Hard Processes”, Laboratori Nazionali di Frascati - Italy, October 18-21 2010