Dark matter from the supersymmetric custodial triplet model

© 2015 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the http://creativecommons.org/licenses/by/3.0/ Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. The supersymmetric custodial triplet model adds to the particle content of the minimal supersymmetric standard model three SU(2)L triplet chiral superfields with hypercharge Y=(0,±1). At the superpotential level, the model respects a global SU(2)L - SU(2)R symmetry only broken by the Yukawa interactions. The pattern of vacuum expectation values of the neutral doublet and triplet scalar fields depends on the symmetry pattern of the Higgs soft breaking masses. We study the cases in which this symmetry is maintained in the Higgs sector and in which it is broken only by the two doublets attaining different vacuum expectation values. In the former case, the symmetry is spontaneously broken down to the vectorial subgroup SU(2)V, and the ρ parameter is protected by the custodial symmetry. However, in both situations, the ρ parameter is protected at tree level, allowing for light triplet scalars with large vacuum expectation values. We find that over a large range of parameter space a light neutralino can supply the correct relic abundance of dark matter either through resonant s-channel triplet scalar funnels or well tempering of the Bino with the triplet fermions. Direct detection experiments have trouble probing these model points because the custodial symmetry suppresses the coupling of the neutralino and the Z, and a small Higgsino component of the neutralino suppresses the coupling with the Higgs. Likewise, the annihilation cross sections for indirect detection lie below the Fermi-LAT upper bounds for the different channels.