Analysis of narrow s-channel resonances at lepton colliders

The procedures for studying a single narrow s-channel resonance or nearly d egenerate resonances at a lepton collider, especially a muon collider, are discussed. In particular, we examine four methods for determining the param eters of a narrow s-channel resonance: scanning the resonance, measuring th e convoluted cross section, measuring the Breit-Wigner area, and sitting on the resonance while varying the beam energy resolution. This latter proced ure is new and appears to be potentially very powerful. Our focus is on com puting the errors in resonance parameters resulting from uncertainty in the beam energy spread. Means for minimizing these errors are discussed. The d iscussion is applied to the examples of a light SM-Higgs, of the lightest p seudogoldstone boson of strong electroweak breaking, and of the two spin-1 resonances of the Degenerate BESS model (assuming that the beam energy spre ad is less than their mass splitting). We also examine the most effective p rocedures for nearly degenerate resonances, and apply these to the case of Degenerate BESS resonances with mass splitting of order the beam energy spr ead.