118417909
Dark matter that can form dark stars
The first stars to form in the Universe may be powered by the annihilation of weakly interacting dark matter particles. These so-called dark stars, if observed, may give us a clue about the nature of dark matter. Here we examine which models for particle dark matter satisfy the conditions for the formation of dark stars. We find that in general models with thermal dark matter lead to the formation of dark stars, with few notable exceptions: heavy neutralinos in the presence of coannihilations, annihilations that are resonant at dark matter freeze-out but not in dark stars, some models of neutrinophilic dark matter annihilating into neutrinos only and lighter than about 50 GeV. In particular, we find that a thermal DM candidate in standard Cosmology always forms a dark star as long as its mass is heavier than 50 GeV and the thermal average of its annihilation cross section is the same at the decoupling temperature and during the dark star formation, as for instance in the case of an annihilation cross section with a non-vanishing s-wave contribution.
14212115
Brane World in Generalized Gravity
We consider Randall-Sundrum(RS) model in generalized gravities and see that the localization of gravity happens in generic situations though its effectiveness depends on the details of the configuration. It is shown that RS picture is robust against quantum gravity corrections ($\phi \R$) as long as the correction is reasonably small. We extend our consideration to the model of scalar(dilaton) coupled gravity which leads us to the specific comparison between RS model and inflation models. The exponential and power law hierarchy in RS model are shown to correspond to the exponential and power law inflation respectively.
118629765
The $\mu$-problem and axion in gauge mediation
We revisit the idea of generating the Higgs {mu} parameter through a spontaneously broken Peccei-Quinn (PQ) symmetry in a gauge-mediated supersymmetry breaking scenario. For the messenger scale of gauge mediation higher than the PQ scale, the setup naturally generates {mu}{approx}m{sub soft} and the Higgs soft parameter B < or approx. O(m{sub soft}) with the CP phase of B aligned to the phase of gaugino masses, while giving the PQ scale v{sub PQ{approx}{radical}}(m{sub soft{Lambda}}), where m{sub soft} denotes the gauge-mediated gaugino or sfermion masses and {Lambda} is the cutoff scale which can be identified as the Planck scale or the grand unified theory scale. The PQ sector of the model results in distinctive cosmology including a late thermal inflation. We discuss the issue of dark matter and baryogenesis in the resulting thermal inflation scenario, and find that a right amount of gravitino dark matter can be produced together with a successful Affleck-Dine leptogenesis, when the gravitino mass m{sub 3/2}=O(100) keV.
118719719
D0 dimuon charge asymmetry from $B_s$ system with Z′ couplings and the recent LHCb result
The D0 collaboration has announced the observation of the like-sign dimuon charge asymmetry since 2010, which has a difference of more than $3\ensuremath{\sigma}$ from the Standard Model prediction. One of the promising explanations is considering the existence of flavor-changing ${Z}^{\ensuremath{'}}$ couplings to the $b$ and $s$ quarks which can contribute to the off-diagonal decay width in the ${B}_{s}\ensuremath{-}{\overline{B}}_{s}$ mixing. Model construction is highly constrained by the recent LHCb data of $1\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ integrated luminosity. In this paper, we analyze the experimental constraints on constructing new physics models to explain the dimuon charge asymmetry from the $CP$ violation of the ${B}_{s}$ system. We present limits on ${Z}^{\ensuremath{'}}$ couplings and show that it is impossible to obtain the $1\ensuremath{\sigma}$ range of the dimuon charge asymmetry without the new contribution in the ${B}_{d}$ system. Even with an arbitrary contribution in the ${B}_{d}$ system, the new couplings must be in the fine-tuned region.
8346663
Supersymmetry hierarchy problems and anomalous horizontal U(1) symmetry
Abstract It is suggested that various hierarchy problems in supersymmetric standard model, i.e. the Yukawa hierarchies, the μ problem, and the suppression of dangerous baryon and/or lepton number (B/L) violating couplings, are resolved altogether in the framework of horizontal U(1) symmetry whose spontaneous breaking results in the appearance of one expansion parameter (the Cabibbo angle). Within a reasonable range of U(1) charges, there exist a few models compatible with experiments. The specific sizes of B/L violating couplings of these models are calculated and several phenomenological consequences are discussed.
7942617
Running of Gauge Couplings in AdS5 via Deconstruction
Running of gauge couplings on a slice of AdS5 is examined using the deconstruction setup. Logarithmic running instead of (linear) power law is justified when the cutoff is lower than the curvature scale. Most of interesting features including the localization of Kaluza-Klein modes and the widening of higher Kaluza-Klein spectrum spacing are well captured within the framework of deconstruction.
119117503
Emergent Schrödinger geometries from mass-deformed CFT
We study an M-theory solution for the holographic flow of AdS4 times Sasaki-Einstein 7-manifolds with skew-whiffing, perturbed by a mass operator. The infrared solution contains the5dimensional Schrödinger geometry after considering the gravity dual of the standard non-relativistic limit of relativistic field theories. The mass deformation of the field theory is discussed in detail for the case with 7 manifold being a round sphere.
116430419
Search For Standard Model Higgs In Two Photon Final State At Atlas
118480483
Surface defects and instanton partition functions
A bstractWe study the superconformal index of five-dimensional SCFTs and the sphere partition function of four-dimensional gauge theories with eight supercharges in the presence of co-dimension two half-BPS defects. We derive a prescription which is valid for defects which can be given a “vortex construction”, i.e. can be defined by RG flow from vortex configurations in a larger theory. We test the prescription against known results and expected dualities. We employ our prescription to develop a general computational strategy for defects defined by coupling the bulk degrees of freedom to a Gauged Linear Sigma Model living in co-dimension two.
118440632
Instantons on the 5-sphere and M5-branes
We calculate the partition functions of supersymmetric gauge theories on S^5, which acquire non-perturbative contributions from instanton loops wrapping its Hopf fiber. The instantons on the CP^2 base equivariantly localize to 3 fixed points of SU(3) Cartans. Using our results, we study the index of the 6d (2,0) theory. We first study the partition functions of maximal SYM with AD(E) gauge groups, which agree with the gravity dual indices on AdS_7 in the large N limits. We also show that the most general partition function of the Abelian theory agrees with the index for a free 6d tensor supermultiplet. We explain possible ambiguities in our 5d approach, role of maximal SUSY, and the Wilson loops on S^5 dual to M2-brane Wilson surfaces in AdS_7.
119259237
Schrödinger invariant solutions of M-theory with enhanced supersymmetry
We find the most general solution of 11-dimensional supergravity compatible with $ \mathcal{N} = 2 $ super-Schrödinger symmetry with six supercharges and $ {\text{SU}}(2) \times {\text{SU}}(2) \times {\text{U}}(1) \times {\mathbb{Z}_2} $ global symmetry. It can be viewed as a one-parameter extension of a recently constructed solution by Ooguri and Park. Our original motivation was to find the gravity dual of the non-relativistic ABJM theory. But, our analysis shows that no such solution exists within the reach of our assumptions. We discuss possible reasons for the non-existence of the desired solution. We also uplift a super-Schrödinger solution in IIB supergravity of Donos and Gauntlett to 11-dimension and comment on its properties.