Model independent analysis of the trilinear gauge boson couplings at LC: role of polarized cross sections

By means of a model-independent analysis, we discuss the constraints on anomalous trilinear gauge-boson couplings that can be obtained from the study of electron-positron annihilation into W pairs at LC with √ s = 0.5 TeV and 1 TeV . We consider the general CP conserving anomalous effective Lagrangian, as well as some specific models with reduced number of independent couplings. The analysis is based on combinations of observables with initial and final state polarizations, that allow to separately constrain the different couplings and to improve the corresponding numerical bounds. Contribution to the Workshop on “ee collisions at TeV energies: The physics potential”, DESY 97-123E Permanent address: Gomel Polytechnical Institute, Gomel, 246746 Belarus. E-mail [email protected] Also supported by the Italian Ministry of University, Scientific Research and Technology (MURST). The values of the WWγ and WWZ couplings, and the corresponding non abelian gauge structure of the Standard Model (SM), have not been tested yet. In this regard, the reaction e + e → W +W (1) at high energy ee colliders is particularly important because, for such process, deviations from the SM predictions due to anomalous values of the trilinear coupling constants are significantly enhanced by increasing the CM energy, and the related sensitivity is improved. The general anomalous trilinear gauge boson Lagrangian has a complicated structure, containing both CP violating and CP conserving interactions. The set of cross-section measurements for process (1), relevant to the CP violating couplings and their separation, was discussed in Ref.[1]. In what follows, we examine the possibility of constraining the CP conserving effective Lagrangian, which can be expressed as follows: [3, 4] L = −ie [