Complex singlet extension of the standard model
We analyze a simple extension of the standard model (SM) obtained by adding a complex singlet to the scalar sector (cxSM). We show that the cxSM can contain one or two viable cold dark matter candidates and analyze the conditions on the parameters of the scalar potential that yield the observed relic density. When the cxSM potential contains a global U(1) symmetry that is both softly and spontaneously broken, it contains both a viable dark matter candidate and the ingredients necessary for a strong first order electroweak phase transition as needed for electroweak baryogenesis. We also study the implications of the model for discovery of a Higgs boson at the Large Hadron Collider.
Additional Information© 2009 The American Physical Society. Received 10 November 2008; published 30 January 2009. V.B. and P.L. thank the Aspen Center for Physics for hospitality. This work was supported in part by the U.S. Department of Energy under Grant Nos. DE-FG02-95ER40896, DE-FG02-05ER41361, DE-FG02-08ER41531, and Contract No. DE-AC02-06CH11357, by the Wisconsin Alumni Research Foundation, the Institute for Advanced Study (PL), and the National Science Foundation Grant No. PHY-0503584.
Published - BARprd09.pdf