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

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 $\tilde{g} \to g \tilde{\chi}^0_{2,3} \to g Z \tilde{\chi}^0_{1}$ where $\tilde{\chi}^0_{2,3}$ and $\tilde{\chi}^0_1$ 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.Comment: 16 pages, 2 figures, 1 tabl

R-symmetric Axion/Natural Inflation in Supergravity via Deformed Moduli Dynamics

We construct a natural inflation model in supergravity where the inflaton is identified with a modulus field possessing a shift symmetry. The superpotential for the inflaton is generated by meson condensation due to strong dynamics with deformed moduli constraints. In contrast to models based on gaugino condensation, the inflaton potential is generated without $R$-symmetry breaking and hence does not depend on the gravitino mass. Thus, our model is compatible with low scale supersymmetry.Comment: 15 page

Simple realization of inflaton potential on a Riemann surface

The observation of the B-mode in the cosmic microwave background radiation combined with the so-called Lyth bound suggests the trans-Planckian variation of the inflaton field during inflation. Such a large variation generates concerns over inflation models in terms of the effective field theory below the Planck scale. If the inflaton resides in a Riemann surface and the inflaton potential is a multivalued function of the inflaton field when it is viewed as a function on a complex plane, the Lyth bound can be satisfied while keeping field values in the effective field theory within the Planck scale. We show that a multivalued inflaton potential can be realized starting from a single-valued Lagrangian of the effective field theory below the Planck scale.Comment: 5 pages, 2 figures; updated to match the published versio

Revisiting the Minimal Chaotic Inflation Model

We point out that the prediction of the minimal chaotic inflation model is altered if a scalar field takes a large field value close to the Planck scale during inflation due to a negative Hubble induced mass. In particular, we show that the inflaton potential is effectively suppressed at a large inflaton field value in the presence of such a scalar field. The scalar field may be identified with the standard model Higgs field or flat directions in supersymmetric theory. With such spontaneous suppression, we find that the minimal chaotic inflation model, especially the model with a quadratic potential, is consistent with recent observations of the cosmic microwave background fluctuation without modifying the inflation model itself.Comment: 5 pages, 3 figure