arXiv:hep-ph/9812388v1 16 Dec 1998 SFB 375-309 TUM-HEP 338/98 DFTT 71/98 Strange form factors of the proton: a new analysis of the ν ( ν ) data of the BNL–734 experiment W.M. Alberico a , M.B. Barbaro a , S.M. Bilenky b,c , J.A. Caballero d,e , C. Giunti a , C. Maieron f , E. Moya de Guerra e and J.M. Ud´ ıas g,e , a INFN, Sezione di Torino and Dipartimento di Fisica Teorica, Universit`a di Torino, Via P. Giuria 1, 10125 Torino, Italy b Joint Institute for Nuclear Research, Dubna, Russia c Institut f¨ ur Theoretische Physik, Technische Universit¨ at Munchen, D–85748 Garching, Germany d Dpto. de F´ ısica At´ omica, Molecular y Nuclear, Universidad de Sevilla, Apdo. 1065, E-41080 Sevilla, Spain e Instituto de Estructura de la Materia, CSIC, Serrano 123, E-28006 Madrid, Spain f Center for Theoretical Physics, Laboratory for Nuclear Science and Department of Physics, Massachussets Institute of Technology, Cambridge, MA 02139, USA g Dpto. de F´ ısica At´ omica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040 Madrid, Spain (February 1, 2008) Abstract We consider ratios of elastic ν (¯ ν )–proton cross sections measured by the Brookhaven BNL–734 experiment and use them to obtain the neutral cur- rent (NC) over charged current (CC) neutrino–antineutrino asymmetry. We discuss the sensitivity of these ratios and of the asymmetry to the electric, magnetic and axial strange form factors of the nucleon and to the axial cutoff mass M A . We show that the effects of the nuclear structure and interactions on the asymmetry and, in general, on ratios of cross sections are negligible. We find some restrictions on the possible values of the parameters charac- terizing the strange form factors. We show that a precise measurement of the neutrino–antineutrino asymmetry would allow the extraction of the axial and vector magnetic strange form factors in a model independent way. The neutrino–antineutrino asymmetry turns out to be almost independent on the electric strange form factor and on the axial cutoff mass. PACS: 12.15.mn, 25.30.Pt, 13.60.Hb, 14.20.Dh, 14.65.Bt 1