Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5,

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Introduction Baryon Spectroscopy What's in Hall B? CLAS Tagged polarized photon beams FROzen Spin Target Glimpse of the data OutlookSummary

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5,

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, N* 

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Experiment cross section, spin observables Experiment cross section, spin observables TheoryLQCD, quark models, QCD sum rules QCD sum rules, …TheoryLQCD, quark models, QCD sum rules QCD sum rules, … Reaction Theory dynamical frameworks Reaction Theory dynamical frameworks Amplitude analysis → multipole amplitudes → phase shifts Amplitude analysis → multipole amplitudes → phase shifts σ,d σ /d Ω, Σ,P,T (beam-target) E,F,G,H, (beam-recoil) C x,C z,O x,O z, (target-recoil) L x,L z, T x,T z, Coupled channels: resonance parameter resonance parameterextraction

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, I. S. Barker, A. Donnachie, J. K. Storrow, Nucl. Phys. B95, 347 (1975). 4 Complex amplitudes - 16 real polarization observables. A complete measurement from 8 carefully chosen observables.

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Emax ~ 6 GeV Imax ~ 200  A Duty Factor ~ 100%  E/E ~ Beam P ≥ 80% E  ~ GeV tagged Hall-BHall-B

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Torus magnet 6 superconducting coils Gas Cherenkov counters e/  separation, 256 PMTs Time-of-flight counters plastic scintillators, 684 photomultipliers Drift chambers 35,000 cells Liquid D 2 (H 2 ) target +  start counter; e mini-torus Electromagnetic calorimeters Lead/scintillator, 1296 photomultipliers

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, backing counters Jefferson Lab Hall B photon tagger: E  = 20-95% of E 0 E  up to ~5.8 GeV dE/E ~10 -3 of E 0

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Circularly polarized beam produced by longitudinally polarized electrons CEBAF electron beam polarization >85% tagged flux ~ MHz (for k>0.5 E 0

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Linearly polarized photons: coherent bremsstrahlung on oriented diamond crystal

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, existing dynamically polarized NH 3, ND 3 target NH 3, ND 3 target polarizing magnet 5.1 T Helmholtz coils reduces acceptance to θ <65 o

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5,

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5,

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5,

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, layers of superconductive wire Field 0.54 T No visible losses of polarization while doing spin rotation →↑

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, butanol 12 C CH 2

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Base temperature Cooling power Polarization 1/e relaxation time Design goal <50 mK 10  W (Frozen) ‏ 20 mW (Polarizing) ‏ 80% 500 hours <50 mK 10  W (Frozen) ‏ 20 mW (Polarizing) ‏ 80% 500 hours 28 mK w/o beam 30 mK with beam 800  mK mK 60 mK +82%-85% 2800 hours (+Pol) ‏ 1600 hours (-Pol) ‏ 28 mK w/o beam 30 mK with beam 800  mK mK 60 mK +82%-85% 2800 hours (+Pol) ‏ 1600 hours (-Pol) ‏ Result Excellent reliability! Continuously running October 29 – February 12. Entire repolarization procedure takes under 6 hours Take data for 5-6 days

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5,

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, g1: E  = 0.5 – 2.9 GeV circularly polarized beam γp→π 0 p, π + n d  /d  γp→ηp d  /d  γp→η'p d  /d  γp→KY (K + Λ, K + Σ 0, K 0 Σ + ) d  /d , P, C x' /C z' γp→π + π - p  

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, g8: E  = 0.9 – 2.1 GeV Linearly polarized γp→π 0 p, π + n  γp→ηp  γp→η'p  γp→KY (K + Λ, K + Σ 0, K 0 Σ + ) , P, T, O x /O z

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, R. Schumacher

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Nikanov et al’.’s refit of Bonn-Gachina multi-coupled- channel isobar model mix includes: S11 wave, P13(1720), P13(1900), P11(1840) K + Σ 0 cross sections also better described with P13(1900) Promote this “missing”resonance from ** to **** status. P13(1900) is found in qqq quark models, but not in quark- diquark models R. Schumacher

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, The  appears 100% polarized when created with a fully polarized beam. R. Schumacher

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, R. Schumacher Energy and angle averages are consistent with unity. No such effect with linearly polarized photons. No such effect for   No model predicted this CLAS result.

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Polarized beam still is not enough, we need polarized target! E02-112: γp→KY (K + Λ, K + Σ 0, K 0 Σ + )‏ E03-105/E04-102: γp→π 0 p, π + n E05-012: γp→ηp E06-013: γp→π + π - p We can do “Complete experiment” for KY!

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, November 3, 2007– February 12, 2008 Longitudinally polarized target Circularly and linearly polarized photon beam GeV Trigger: at least one charged particle in CLAS

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Very preliminary! Helicity asymmetry E Raw asymmetry

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Circularly polarized photon beam on longitudinally polarized target E, P, Lx/Lz, Cx/Cz Linearly polarized photon beam on longitudinally polarized target , G, P, (Tx/Tz) Ox/Oz Circularly polarized photon beam on transversely polarized target T, F, P, Tx/Tz, Cx/Cz Linearly polarized photon beam on transversely polarized target , H, T, P, (Lx/Lz) ‏ Complete Scheduled for 2010

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, To reveal isospin structure it is essential to do measurements on the neutron G13 running period accumulated large dataset with circularly an linearly polarized photons on liquid deuterium unpolarized target The data are being analized

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, A. Sandorfi

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, A. Sandorfi

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, New addition in Hall B of Frozen Spin Target, with both, longitudinal and transverse polarization significantly advances our experimental capabilities. It is possible to perform complete experiment of KY photoproduction and nearly complete for other final states. Entire program is more than just a sum of several experiments, observables for all final states are measured simultaneously under the same experimental conditions and have the same systematic uncertainties. It can be considered as “coupled channel experiment” ultimately providing data for coupled channel analysis and extraction of parameters of baryon resonances. Supply data EBAC – Excited Baryon Analysis Center at JLAB Experiments with HD-Ice target are in preparation

Eugene Pasyuk DSPIN-09 Dubna, September 1-5, Eugene Pasyuk DSPIN-09 Dubna, September 1-5, The CLAS Collaboration Idaho State University, Pocatello, Idaho INFN, Laboratori Nazionali di Frascati, Frascati, Italy INFN, Sezione di Genova, Genova, Italy Institut de Physique Nucléaire, Orsay, France ITEP, Moscow, Russia James Madison University, Harrisonburg, VA Kyungpook University, Daegu, South Korea University of Massachusetts, Amherst, MA Moscow State University, Moscow, Russia University of New Hampshire, Durham, NH Norfolk State University, Norfolk, VA Ohio University, Athens, OH Old Dominion University, Norfolk, VA Arizona State University, Tempe, AZ University of California, Los Angeles, CA California State University, Dominguez Hills, CA Carnegie Mellon University, Pittsburgh, PA Catholic University of America CEA-Saclay, Gif-sur-Yvette, France Christopher Newport University, Newport News, VA University of Connecticut, Storrs, CT Edinburgh University, Edinburgh, UK Florida International University, Miami, FL Florida State University, Tallahassee, FL George Washington University, Washington, DC University of Glasgow, Glasgow, UK Rensselaer Polytechnic Institute, Troy, NY Rice University, Houston, TX University of Richmond, Richmond, VA University of South Carolina, Columbia, SC Thomas Jefferson National Accelerator Facility, Newport News, VA Union College, Schenectady, NY Virginia Polytechnic Institute, Blacksburg, VA University of Virginia, Charlottesville, VA College of William and Mary, Williamsburg, VA Yerevan Institute of Physics, Yerevan, Armenia Brazil, Germany, Morocco and Ukraine, as well as other institutions in France and in the USA, have individuals or groups involved with CLAS, but with no formal collaboration at this stage.