ATLAS on-Z Excess via gluino-Higgsino-singlino decay chains in the NMSSM

Abstract

Recently the ATLAS experiment has reported 3.0 sigma excess in an on-Z signal region in searches for supersymmetric particles. We find that the next-to-minimal supersymmetric standard model can explain this excess by the production of gluinos which mainly decay via $\tilde{g}\to g{\tilde{\chi }}_{2,3}^0\to gZ{\tilde{\chi }}_1^0$ where ${\tilde{\chi }}_{2,3}^0$ and ${\tilde{\chi }}_1^0$ are the Higgsino and the singlino-like neutralinos, respectively. We show that the observed dark matter density is explained by the thermal relic density of the singlino-like neutralino, simultaneously. We also discuss the searches for the Higgs sector of this scenario at the Large Hadron Collider.

Comments: 16 pages, 2 figures, 1 table