14787353
Gauss-Bonnet interaction in Randall-Sundrum compactification
We show that the Gauss-Bonnet term is the only consistent curvature squared interaction in the Randall-Sundrum model and various static and inflationary solutions can be found. And from metric perturbations around the RS background with a single brane embedded, we also show that for a vanishing Gauss-Bonnet coefficient, the brane bending allows us to reproduce the 4D Einstein gravity at the linearized level.
119248157
Vector Higgs-portal dark matter and the invisible Higgs
The Higgs sector of the Standard Model offers a unique probe of the hidden sector. In this work, we explore the possibility of renormalizable Higgs couplings to the hidden sector vector fields which can constitute dark matter (DM). Abelian gauge sectors with minimal field content, necessary to render the gauge fields massive, have a natural Z2 parity. This symmetry ensures stability of the vector fields making them viable dark matter candidates, while evading the usual electroweak
119217517
U(1)R mediation from the flux compactification in six dimensions
We consider a supersymmetric completion of codimension‐two branes with nonzero tension in a 6D gauged supergravity. As a consequence, we obtain the football solution with 4D Minkowski space as a new supersymmetric background that preserves 4D N = 1 SUSY. In the presence of brane multiplets, we derive the 4D effective supergravity action for the football background and show that the remaining modulus can be stabilized by a bulk non‐perturbative correction with brane uplifting potentials at a zero vacuum energy. We find that the U(1)R mediation can be a dominant source of SUSY breaking for a brane scalar with nonzero R charge.
14096456
Wave function of the radion in the brane background with a massless scalar field and a self-tuning problem
We consider flat solutions in a brane world model with a massless scalar field appearing in 5D ${H}_{\mathrm{MNPQ}}^{2}.$ Since those solutions have naked bulk singularities or are such that the 4D Planck mass is divergent, we should have a compact extra dimension, the size of which is then fixed by brane tension(s) and the bulk cosmological constant. By inspecting scalar perturbations around the flat solutions, we find that there is no zero mode for the radion and radion modes have only positive masses. This result confirms the fact that the radius of the extra dimension cannot be adjusted independently of the parameters of the model, and thus that the model considered does not solve the problems encountered in other approaches to the self-tuning of the cosmological constant.
14725085
Various modified solutions of the Randall–Sundrum model with the Gauss–Bonnet interaction
Abstract The Gauss–Bonnet interaction is the only consistent quadratic interaction below the Planck scale in the Randall–Sundrum compactification. We study various static and inflationary solutions including this Gauss–Bonnet interaction.
119351828
Self-tuning solution of the cosmological constant problem with antisymmetric tensor field
We obtain the self-tuning solution of the cosmological constant problem in the Randall-Sundrum model with introducing a three-index antisymmetric tensor field of a specific form in the Lagrangian. We also consider the dual description of the self-tuning solution.
9421064
Characteristics of QCD phase transitions in an extended Skyrme model on S**3
We study the characteristics of the QCD phase transitions in dense hadronic matter using the Skyrme model constructed on S^3. We find numerically the localized solutions on $S^3$ using the extended Skyrme model which implements correctly the scale symmetry of QCD. The transition from the localized phase to the delocalized phase is found to be of first order at the critical radius of the hypersphere, $L_c$. The chiral restoration and the gluon decondensation also take place at the same critical size.
118567798
Long-range interaction effects on neutrino oscillation
Motivated by the recent anomaly in the muon neutrino and anti-muon neutrino disappearance experiments, we consider a long-range interaction with an extremely light gauge boson and extraordinarily weak coupling. A long-range interaction, consistent with current bounds, could have very pronounced effects on atmospheric neutrino disappearance that will be studied with the IceCube DeepCore array, currently in operation, and can have a significant effect on future high-precision long-baseline oscillation experiments. This invited talk was based on the paper with Hooman Davoudiasl and William Marciano [1].
16281369
Common gauge origin of discrete symmetries in observable sector and hidden sector
An extra Abelian gauge symmetry is motivated in many new physics models in both supersymmetric and nonsupersymmetric cases. Such a new gauge symmetry may interact with both the observable sector and the hidden sector. We systematically investigate the most general residual discrete symmetries in both sectors from a common Abelian gauge symmetry. Those discrete symmetries can ensure the stability of the proton and the dark matter candidate. A hidden sector dark matter candidate (lightest U-parity particle or LUP) interacts with the standard model fields through the gauge boson Z' which may selectively couple to quarks or leptons only. We make a comment on the implications of the discrete symmetry and the leptonically coupling dark matter candidate, which has been highlighted recently due to the possibility of the simultaneous explanation of the DAMA and the PAMELA results. We also show how to construct the most general U(1) charges for a given discrete symmetry, and discuss the relation between the U(1) gauge symmetry and R-parity.
118614634
Dark side of Higgs diphoton decays and muon g − 2
We propose that the LHC hints for a Higgs diphoton excess and the muon g-2 (g_mu-2) discrepancy between theory and experiment may be related by vector-like "leptons" charged under both U(1)_Y hypercharge and a "dark" U(1)_d. Quantum loops of such leptons can enhance the Higgs diphoton rate and also generically lead to U(1)_Y - U(1)_d kinetic mixing. The induced coupling of a light U(1)_d gauge boson Z_d to electric charge can naturally explain the measured g_mu-2. We update Z_d mass and coupling constraints based on comparison of the electron g-2 experiment and theory, and find that explaining g_mu-2 while satisfying other constraints requires Z_d to have a mass ~ 20-100 MeV. We predict new Higgs decay channels gamma Z_d and Z_d Z_d, with rates below the diphoton mode but potentially observable. The boosted Z_d -> e+e- in these decays would mimic a promptly converted photon and could provide a fraction of the apparent diphoton excess. More statistics or a closer inspection of extant data may reveal such events.
118631955
Identifying Sneutrino Dark Matter: Interplay between the LHC and Direct Search
Under R parity, the lightest supersymmetric particle (LSP) is stable and may serve as a good dark matter candidate. The R parity can be naturally introduced with a gauge origin at the TeV scale. We go over why a TeV scale B-L gauge extension of the minimal supersymmetric standard model is one of the most natural, if not demanded, low energy supersymmetric models. In the presence of a TeV scale Abelian gauge symmetry, the (predominantly) right-handed sneutrino LSP can be a good dark matter candidate. Its identification at the LHC is challenging because it does not carry any standard model charge. We show how we can use the correlation between the LHC experiments (dilepton resonance signals) and the direct dark matter search experiments (such as CDMS and XENON) to identify the right-handed sneutrino LSP dark matter in the B-L extended minimal supersymmetric standard model.