(=POlarisation at Work in Energetic Reactions)


Minutes of the Polarisationsession at Prag, November 2002

              i) Ties Behnke told us the 'hot' news from the project 'E166' at SLAC.
                  This project is an international collaboration to test the production
                  of polarised positrons by undulator radiation. The high qualtity low
                  emittance beam at the SLAC FFTB (50 GeV) would be ideal for this
                  The proposal has been presented to the EPAC meeting on November 20 and
                  we all hope that our POWER friends at SLAC got a 'yes' for this great

            ii)  Karol Kolodziej made a nice introduction into the use of transversely
                  polarized beams for the study of longitudinal W's in e+e-->WW.
                  The transverse e+ and e- beams project out W_L. The W_L are
                  crucial for electroweak symmetry breaking. The decisive observable
                  is the azimuthal asymmetry, which is about 10% at high energies.
                  Information about W_L can therefore be derived without analysing final
                  state polarisations. For this study both beams e- and e+ have to be
                  polarised since sigma_T sim PT(e-) x PT(e+)

           iii) Wolfgang Kilian gave a status report about the WHIZARD MC generator.
                  It is a program for Multi-Particle SM Processes. Full polarisation information
                  is available. Also processes with transversely polarised initial beams can be simulated.
                  Klaus Desch+Student volunteered to provide simulation studies for
                  e+e- -> WW with transverse beams

            iv)  Felix Nagel told us the news about the use of polarised beams
                   in e+e- -> W W and the study of triple gauge couplings in a general
                   parametrization with 28 parameters using optimal observables.
                   The sensitivity increases by about a factor 3 with only P(e-)
                   and by about a factor 5 with both beam polarised.
                   For one TGC even the longitudinal polarisation is not
                   sufficient, however the use of transverse beams seems to be  promising.
             v)  Alexander Wagner gave some new results about polarisation effects in
                   SUSY studies: testing the mixing matrix of Sleptons (which should
                   be diagonal for the first two families) via threshold
                   studies or via polarisation effects. Next results in Amsterdam.

            vi)   Further new studies:
                    Hahn, Heinemeyer, Weiglein: In order to produce the CP-even Higgs in WW fusion
                    if m_A,m_H>>m_Z, the use of both beams polarised could be decisive since the
                    coupling cos(beta-alpha) -> 0 in this case and very, very small rates are expected.


                i)  Transversely polarised beams in t production?
                ii) Transversely polarised beams in the case of CP violation?
               iii)  write-up

Last update of this page: 25-November-02

by G. Moortgat-Pick