Hi john:
the ed-vector spin correlation parameter can be redundantly determined
by determining the asymmetry for fixed spin (flipping beam) or fixed
beam helicity (flipping target).
We could wave hands at false asymmetries there, but actually only if
we have absolute |V+|, |V-| information from QE ee'p.
-- ________________________________________________________________________________ Tancredi Botto, phone: +1-617-253-9204 mobile: +1-978-490-4124 research scientist MIT/Bates, 21 Manning Av Middleton MA, 01949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^On Sun, 23 May 2004, John Calarco wrote:
> > How is the deuterium target vector false asymmetry determined? One > might want to think about this since the target ONLY vector > asymmetry vanishes due to time reversal invariance under the > assumption of the 1-photon exchange approximation. It may not if > 2-photon exchange effects are important. There is reason to believe > that if 2-photon exchange effects are important in ep scattering, > they may be even stronger in ed scattering due to the fact that > the deuterium continuum is only 2.2 MeV away as opposed to 140 MeV > in ep scattering. > > >
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