1. Eurotag Workshop Sept 1 st - 2 nd 2008 Ken Livingston, University of Glasgow Overview of I3HP, JRA, Eurotag Summary of Eurotag objectives Aims of this workshop Reports from the “Infrastructures” Current status, recent developments Physics highlights, future plans Reports on progress of Eurotag Objectives Photon tagging Linear polarization Physics results from the photon facilities Completed measurements Ongoing analysis, future aims Conclusion Achievements, reporting, accounting

2. Eurotag (JRA in I3HP)‏ Development of the European Tagged photon facilities. Spokesperson: Ken Livingston, Glasgowurl: www.nuclear.gla.ac.uk/~kl/Eurotag Upgrade to 250MeV New Coherent Brem New Tagger Crystal Barrel upgrade Coherent Brem. Crystal Ball Upgrade to 1.5GeV Upgrade of Tagger Upgrade of C. Brem Beam intensity x2 Lin. Pol 96% Members: Glasgow, Bonn, Giessen, INFN, Lund, Mainz, Tuebingen, Kharkov, JLab Bremsstrahlung facilities Improvements to provision of linearly polarised photon beams Award: 600k€

3. Eurotag objectives Photon Tagging Develop prototype focal plane modules (amplifier + discriminator + coincidence)‏ Development of a prototype endpoint tagger Linearly Polarised Photons Develop prototype photon beam profiler to investigation “quazi-channeling radiation”. Develop linearly polarised photon beam at MAXLab, Lund. Develop software toolkit for polarised photon beams. Develop “proof of principle polarimeter” for linearly polarised photons. Develop polarimetry for double polarisation experiments. Peak > 90% pol. Glasgow tagging spectrometer upgrade at MAMI Coherent bremsstrahlung photons

4. The advantage of linearly polarised photons    P cos 2  (... and polarisation observables in general )‏

5. Linearly polarised photons: physics programme “Stand alone measurements” Photon asymmetry Σ Eg. γ p → K + Λ 0 → K + π - p For double polarisation observables Eg. Pseudoscalar meson “Complete measurement” Many expts across world requiring Linear Pol. See various other later talks.

6. Tagged Coherent bremsstrahlung Tagging spectrometer with high rate, good energy and timing resolution High precision goniometer Software for alignment, running experiments Polarimetry

7. Eurotag workshop: Objectives Exchange information, celebrate achievements On Eurotag objectives More generally (physics, infrastructs)‏ Where to go next Publications Making results and tools available Transfer of Knowledge Information for reporting purposes Big final report due Dissemination Synergy Accounting