TRILINEAR COUPLINGS AMONG THE ELECTROWEAK VECTOR BOSONS AND THEIR DETERMINATION AT LEP2

We present a detailed investigation of the potential of LEP2 to measur e the (trilinear) couplings of the vector bosons, Z0W+ W- and gammaWW-, among one another. The restrictions imposed on non-standard trilin ear couplings by symmetry requirements, thus excluding violent boson-l oop divergences and a violent growth of tree amplitudes for vector-bos on scattering, are discussed in detail. We elaborate on how to extract the W+/- spin-density matrix and the W+, W- spin correlations from fu ture data. Various theoretically motivated fits to artificial ''data'' on e+ e- --> W+W- are carried out in order to evaluate the potential of LEP2 for, the measurement of trilinear vector boson couplings. We s tress that a direct measurement of the couplings of the vector bosons with one another is indispensable for a verification of the basic SU(2 )L X U(1)Y structure of the present electroweak theory. Such measureme nts at LEP2 improve indirect LEP1 bounds by factors which occasionally reach a full order of magnitude.