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This article explores global issues in B-Factories such as BaBar vs. Belle, background sources, long-term limitations, and the future of Super B-Factory. It includes suggestions, questions, and comparisons of beam-gas, luminosity, and Touschek backgrounds.
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BBBTF: where do we go from here? – a personal viewpoint - • Global issues • today’s B-Factories (up to ~ 2007) • ...including some specific suggestions, and • some detailed questions • to-morrow’s Super B-Factory W. Kozanecki, CEA-Saclay
Global issues: BaBar vs. Belle • Relative importance of the various background sources? • only common one seems to be beam-gas (before BBR thermal limitations) • Belle • important: SR, beam-gas, Touschek. What is the main long-term limitation? • no concern (?): luminosity, beam-beam • BaBar • limiting (now): thermal outgassing (beam-gas) • limiting (future): luminosity backgrounds, HER b-g, beam-beam • no concern: SR, Touschek
Global issues: BaBar vs. Belle (II) • Today’s B-Factories (up to 2007-8): 4 main questions • can we understand quantitatively how different / similar our beam-gas backgrounds are, excluding or subtracting (for Babar) • the mid-plane (magnetic separation) • the thermal outgassing problem (use Jan 04 background characterization data) • why is the luminosity background so small in Belle (and will it stay that way...) ? • would a simple (Turtle-like) simulation make sense for Belle? (BaBar: in progress) • why is the Touschek background so large in Belle? • ...or is it? i.e. is it large on an absolute or on a relative scale? • can one make a parametric comparison using PEP-II & KEK-B beam parameters? • where (and when) do the main limitations appear?
Detailed questions (the beginning of a list...) • Does Belle plan a detailed background characterization at some stage? • Does Belle have any neutron background? • KLM: in the past yes, what about now? • anywhere else? • One of our EMC experts (J. Va’vra) is interested in the long-term leakage-current history of the Belle EMC diodes (Babar sees a definite degradation) • If Belle had to redesign the handling of SR backgrounds, what would you do differently?
Global issues: the future • Tomorrow’s Super B-Factory (proposal by G. Wormser) • estimate all background components in a future machine • add together those seen by Belle and those seen by BaBar • as a starting point , use either KEKB upgrade or the Slac SuperB parameter list