Mass splitting in supersymmetric theories from an effective lagrangian point of view

Gauge and global internal symmetries, even when spontaneously broken, restrict the possible mass splittings within supermultiplets. A systematic method of analysis is presented which is applicable both for 〈F〉- and 〈D〉-type supersymmetry breaking, with emphasis on avoiding unacceptable splittings within the quark and lepton supermultiplets. Expressions for gluino and photino masses are also obtained.     

Neutrino and antineutrino proton scattering data and the ratio of down to up quarks in the proton

New data on the x-dependence of the ratio of down to up quarks in the proton are presented from neutrino and antineutrino experiments using the Fermilab 15-foot bubble chamber filled with hydrogen. The new data are in good agreement with existing data from electron scattering experiments performed at SLAC but are not accurate enough at large x to discriminate between the QCD prediction and a (1 ? x) behavior as x → 1.