EPJ Web of Conferences (Apr 2010)

Recent results from the G0 experiment

  • Roos P.,
  • Roche J.,
  • Ramsay W.D.,
  • Quinn B.,
  • Poelker M.,
  • Pitt M.L.,
  • Pillot P.,
  • Phillips S.K.,
  • Pate S.F.,
  • Papavassiliou V.,
  • Page S.A.,
  • van Oers W.T.H.,
  • Muether M.,
  • Mkrtchyan H.,
  • Mihovilovic M.,
  • Micherdzinska A.,
  • McKeown R.D.,
  • Martin J.W.,
  • Mammei J.,
  • Lung A.,
  • Liu J.,
  • Lee L.,
  • Kox S.,
  • Korsch W.,
  • King P.M.,
  • Jones M.,
  • Horn T.,
  • Hansknecht J.,
  • Guillard G.,
  • Grames J.,
  • Gericke M.T.W.,
  • Gaskell D.,
  • Furget C.,
  • Franklin G.,
  • Flores G.,
  • Davis C.A.,
  • Ellis C.,
  • Coppens A.,
  • Chao Y.-C.,
  • Capuano C.L.,
  • Breuer H.,
  • Bosted P.,
  • Birchall J.,
  • Benmokhtar F.,
  • Bimbot L.,
  • Benesch J.,
  • Beise E.J.,
  • Beck D.H.,
  • Bailey S.L.,
  • Arvieux J.,
  • Armstrong D.S.,
  • Androić D.,
  • Real J.S.,
  • Schaub J.,
  • Seva T.,
  • Simicevic N.,
  • Smith G.R.,
  • Spayde D.T.,
  • Stutzman M.,
  • Suleiman R.,
  • Tadevosyan V.,
  • Versteegen M.,
  • Voutier E.,
  • Vulcan W.,
  • Wells S.P.,
  • Williamson S.E.,
  • Wood S.A.

DOI
https://doi.org/10.1051/epjconf/20100303004
Journal volume & issue
Vol. 3
p. 03004

Abstract

Read online

We have measured parity violating asymmetries in elastic electron-proton and quasi-elastic electrondeuteron scattering at backward electron angle. These measurements have been done at two momentum transfers : Q2 = 0.22 and 0.63 (GeV/c)2 . Together with our previous forward angle measurement [1], we can extract strange quark contributions to the electromagnetic form factors of the nucleon, as well as nucleon axial form factor coming from the neutral weak interaction. The results indicate a strange quark magnetic contribution close to zero at these Q2 , and a possible non zero strange quark electric contribution for the high Q2 . The first Q2 behavior measurement of the nucleon axial form factor in elastic electron scattering shows a good agreement with radiative corrections calculated at Q2 = 0 and with a dipole form using the axial mass determined in neutrino scattering.