Detecting a Higgs Pseudoscalar with a Z Boson at the LHC

We have adopted two Higgs doublet models to study the production of a Higgs pseudoscalar (A) in association with a Z gauge boson from gluon fusion (gg → ZA) at the CERN Large Hadron Collider. The prospects for the discovery of ZA → ll̄bb̄ are investigated with physics backgrounds and realistic cuts. Promising results are found for mA ∼ 260 GeV in two Higgs doublet models when the heavier Higgs scalar (H) can decay into a Z boson and a Higgs pseudoscalar (A). Although the cross section of gg → ZA is usually small in the minimal supersymmetric standard model, it can be significantly enhanced in general two Higgs doublet models. This discovery channel might provide an opportunity to search for a Higgs scalar and a Higgs pseudoscalar simultaneously at the LHC and could lead to new physics beyond the Standard Model and the minimal supersymmetric model. Typeset using REVTEX E-mail address: [email protected] Present address: Department of Physics, California Institute of Technology, Pasadena, CA 91125. E-mail address: [email protected]