Enhancement of Charged Higgs Production in Association With W at Muon   Colliders in General Two Higgs Doublet Models
  The charged Higgs associated production with a W boson has a smooth cross section as a function of the charged Higgs mass at muon colliders. The cross section in Minimal Supersymmetric Standard Model is about 25fb in the range 200 GeV < mH < 400 GeV with tanbeta = 50. This is much larger than the corresponding cross section at an e+e- collider which reaches a fraction of femtobarn. The observability of this channel at a muon collider has been recently studied in an earlier work leading to the result that with 1 ab-1, a 5sigma signal can be observed throughout the aforementioned mass range. In this paper, results of a study based on a general two Higgs doublet model (type II and III) are presented and the cross section of this process in the most sensitive parameter space is evaluated. It is concluded that the cross section of this process increases with increasing neutral Higgs boson masses involved in the s-channel diagram and can be as large as several picobarn with tanbeta = 50. The region of "physical Higgs boson mass" parameter space which could lead to a 5 sigma signal at 50fb-1 is specified. 
Majid Hashemi
hep-ph