199734
Mixed bino–wino–higgsino dark matter in gauge messenger models
Almost degenerate bino and wino masses at the weak scale constitute one of the unique features of gauge messenger models. The lightest neutralino is a mixture of bino, wino and higgsino and can produce the correct amount of dark matter density if it is the lightest supersymmetric particle. Furthermore, as a result of the squeezed spectrum of superpartners which is typical for gauge messenger models, various co-annihilation and resonance regions overlap and very often the correct amount of neutralino relic density is generated by an interplay of several processes. This feature makes the explanation of the observed amount of the dark matter density much less sensitive to fundamental parameters. We calculate the neutralino relic density assuming a thermal history and present both spin independent and spin dependent cross sections for direct detection. We also discuss phenomenological constraints from b → sγ and muon g−2 and compare results obtained using gauge messenger models to well known results for the mSUGRA scenario.
119212900
Light neutralino dark matter with a very light Higgs boson for CoGeNT and DAMA/LIBRA data
Recently, the CoGeNT collaboration reported weakly interacting massive particle candidate-signal events exceeding the known backgrounds where the light WIMP with large cross section is supported. Motivated by this issue, we analyze a light neutralino dark matter scenario with a very light CP-even Higgs mediation in the elastic scattering process, which provides the mass and direct detection cross section to explain the CoGeNT result. To be compatible with the result of LEP experiments, the light CP-even Higgs is favored to be at around 9-10 GeV. Such a scenario can be realized in the "beyond the minimal supersymmetric standard model" context. The relic abundance consistent with the WMAP result can be obtained when twice neutralino mass is close to the light Higgs mass via the resonance enhancement of the annihilation cross section. As a result, the neutralino mass is predicted to be at around 5-6 GeV.
14019653
Top–bottom mass hierarchy, $s-\mu$ puzzle and gauge coupling unification with split multiplets
Abstract. Supersymmetric 5D SU(5) grand unification is considered. SU(5) is broken down to $G_{\mathrm{{SM}}}=SU(3)\times SU(2)\times U(1)$ by the $Z_2\times Z_2'$ assignment of the bulk field(s). The matter fields are located at the fixed point(s). In the bulk, a Higgs multiplet $\bar 5_H$ (containing the bottom doublet $H_1$) and the SU(5) gauge multiplet are located. At one fixed point, $H_2$ (the top doublet) and the standard model matter multiplets are presented. Because of the difference of the locations of $H_1$ and $H_2$, one can obtain a hierarchy between top and bottom Yukawa couplings. We also present a possible way to understand the s–$\mu$ mass puzzle in this framework of the split multiplet.
8099383
Gauge Messenger Models
We consider gauge messenger models in which X and Y gauge bosons and gauginos are messengers of supersymmetry breaking. In simple gauge messenger models, all the soft parameters except μ and Bμ are calculated in terms of a single scale parameter MSUSY which is proportional to F / MGUT. Unique prediction on dark matter in gauge messenger models is discussed. (Based on hep‐ph/0601036 and hep‐ph/0607169)
14499725
The mu problem and B and L conservation with a discrete gauged R symmetry
We examine in a generic context how the {mu} problem can be resolved by means of a spontaneously broken gauge symmetry. We then focus on the new scheme based on a discrete gauge R symmetry which is spontaneously broken by nonperturbative hidden sector dynamics triggering supersymmetry breaking also. The possibility to suppress the dangerous baryon and/or lepton-number-violating interactions by means of this discrete R symmetry is examined also together with some phenomenological consequences. {copyright} {ital 1997} {ital The American Physical Society}
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.
119264805
Supersymmetric vacua of mass-deformed M2-brane theory
Abstract We count the supersymmetric vacua of mass-deformed N = 6 U ( N ) × U ( N ) Chern–Simons-matter theory by calculating the Witten index. When the Chern–Simons level k is 1, our result perfectly agrees with that from the gravity dual, given by partitions of N . For general k , our index generalizes partitions of N , including additional degrees. We also comment on non-relativistic superconformal theories constructed from this model.
118090569
Holography of mass-deformed M2-branes
We find and study the gravity duals of the supersymmetric vacua of N=6 mass-deformed Chern-Simons-matter theory for M2-branes. The classical solution extends that of Lin, Lunin and Maldacena by introducing a Z_k quotient and discrete torsions. The gravity vacua perfectly map to the recently identified supersymmetric field theory vacua. We calculate the masses of BPS charged particles in the weakly coupled field theory, which agree with the classical open membrane analysis when both calculations are reliable. We also comment on how non-relativistic conformal symmetry is realized in our gravity duals in a non-geometric way.
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.
118339519
5-dim superconformal index with enhanced En global symmetry
A bstractThe five-dimensional $ \mathcal{N}=1 $ supersymmetric gauge theory with Sp(N) gauge group and SO(2Nf) flavor symmetry describes the physics on N D4-branes with Nf D8-branes on top of a single O8 orientifold plane in Type I′ theory. This theory is known to be superconformal at the strong coupling limit with the enhanced global symmetry $ {E_{{N_f +1}}} $ for Nf ≤ 7. In this work we calculate the superconformal index on S1 × S4 for the Sp(1) gauge theory by the localization method and confirm such enhancement of the global symmetry at the superconformal limit for Nf ≤ 5 to a few leading orders in the chemical potential. Both perturbative and (anti)instanton contributions are present in this calculation. For Nf = 6, 7 cases some issues related the pole structure of the instanton calculation could not be resolved and here we could provide only some suggestive answer for the leading contributions to the index. For the Sp(N) case, similar issues related to the pole structure appear.
122815252
Production and optical properties of Gd-loaded liquid scintillator for the RENO neutrino detector
Abstract Reactor experiment for neutrino oscillation (RENO) began data-taking from August 2011. It successfully observed reactor antineutrino disappearance in April 2012 to measure the smallest mixing angle of θ 13 . Two identical detectors, one at near location and the other at far location, are constructed at the Yonggwang nuclear power plant in South Korea, to compare the observed reactor neutrino fluxes. Each RENO detector is filled with 16 mass tons of Gadolinium loaded liquid scintillator (GdLS) in the neutrino target region, and with 28 mass tons of unloaded liquid scintillator (LS) in the γ - catcher region surrounding the target. LS was developed to satisfy chemical, physical, optical properties, and safety requirements. Linear alkyl benzene (LAB) was chosen as a solvent because of its high flash-point, sufficient light yield, and being environmentally friendly. GdLS is carefully developed to keep a long attenuation length and high light yield for a long time period. In this paper, we report the characteristics and mass production of the RENO LS and GdLS.