Studying Trilinear Gauge Couplings at Linear Collider Energies

We investigate the sensitivity of the semileptonic processes e+e− → l−ν̄l q q̄′, l = e or μ, on the non-standard trilinear gauge couplings, using the optimal observables method at Linear Collider energies. Our study is based on the four-fermion generator ERATO. Taking into account all possible correlations between the different trilinear gauge coupling parameters, we show that they can be measured with an accuracy of 10−3 to 10−4 for typical Linear Collider energies and luminosities. E-mail: [email protected], [email protected]. The future e+e− linear colliders (LC), with energies ranging from a few hundreds of GeV up to a couple of TeV, provide particle physics with an enormous potential for studying Nature to the deepest level ever achieved [1]. Although at these energies direct searches for new particles and their interactions will eventually attract most of the physics interest, LC offer also the unique possibility to study to an extremely high accuracy, the properties of the existing particles, like those of the massive electroweak gauge bosons W and Z. Therefore, an important project at the LC energies will be the determination of the trilinear gauge couplings (TGC) [2, 3], which are a characteristic manifestation of the underlying non-Abelian symmetry of elementary particle interactions [4] and at the same time an interesting probe of New Physics (NP). In order to study the TGC we need a parameterization of the vector gauge boson interactions that goes beyond the Standard Model . The most general such parameterization is given by [5]: LTGC = ∑