Muon Anomalous Magnetic Moment in a Supersymmetric U(1)' Model

Abstract

We study the muon anomalous magnetic moment a_μ= (g_μ- 2)/2 in a supersymmetric U(1)' model. The neutralino sector has extra components from the superpartners of the U(1)' gauge boson and the extra Higgs singlets that break the U(1)' symmetry. The theoretical maximum bound on the lightest neutralino mass is much smaller than that of the Minimal Supersymmetric Standard Model (MSSM) because of the mixing pattern of the extra components. In a U(1)' model where the U(1)' symmetry is broken by a secluded sector (the S-model), tanβis required to be < 3 to have realistic electroweak symmetry breaking. These facts suggest that the a_μprediction may be meaningfully different from that of the MSSM. We evaluate and compare the muon anomalous magnetic moment in this model and the MSSM and discuss the constraints on tanβand relevant soft breaking terms. There are regions of the parameter space that can explain the experimental deviation of a_μfrom the Standard Model calculation and yield an acceptable cold dark matter relic density without conflict with collider experimental constraints.