Leptonic signals from off-shellZ boson pairs at hadron colliders

We calculate the invariant amplitudes for the process γ→γ in the full electroweak standard model and present them in concise analytical form. The differential polarized and total unpolarized cross sections are discussed in the MeV region and in the GeV region. The cross section is completely dominated by the fermion contributions at low energies whereas it is determined by the W-boson diagrams at high energies $\left( {\sqrt s \gtrsim 1TeV} \right)$ .     

Preparation,Properties and Reactions of Polychloroamine Derivatives

Highly chlorinated amine derivatives can be prepared by the high-temperature chlorination of amines and amine derivatives. Essential for the success of this reaction is an adequate temperature control suited to the constitution of the amines. In many cases the chlorination products achieve stability by cleavage reactions with formation of the imidic acid chloride or isocyanide dichloride grouping. Cyclic compounds are formed under special conditions. The chlorination process described can be used to obtain e.g. polychloroaryl and polychloroalkyl isocyanide dichlorides, polychloroaryl and polychloroalkyl imidic acid chlorides, and polychloroheterocyclic compounds.