Supersymmetry without a Light Higgs Boson

Motivated by the absence, so far, of any direct signal of conventional low-energy supersymmetry, we explore the consequences of making the lightest Higgs boson in supersymmetry relatively heavy, up to about 300 GeV, in the most straightforward way, i.e. via the introduction of a chiral singlet S with a superpotential interaction with the Higgs doublets, \lambda S H_1 H_2. The coupling \lambda dominates over all the other couplings and, to maintain the successful perturbative analysis of the ElectroWeak Precision Tests, is only restricted to remain perturbative up to about 10 TeV. The general features of this "\lambda SUSY" framework, which deviates significantly from the MSSM or the standard NMSSM, are analyzed in different areas: ElectroWeak Precision Tests, Dark Matter, naturalness bounds on superparticle masses, and LHC signals. There is a rich Higgs/Higgsino sector in the (200-700)GeV mass region, which may include LSP Higgsino dark matter. All other superpartners, apart from the top squarks, may naturally be heavier than 1-2 TeV. This picture can be made consistent with gauge coupling unification.Comment: 27 page

Asymptotics for testing hypothesis in some multivariate variance components model under non-normality

AbstractWe consider the problem of deriving the asymptotic distribution of the three commonly used multivariate test statistics, namely likelihood ratio, Lawley–Hotelling and Bartlett–Nanda–Pillai statistics, for testing hypotheses on the various effects (main, nested or interaction) in multivariate mixed models. We derive the distributions of these statistics, both in the null as well as non-null cases, as the number of levels of one of the main effects (random or fixed) goes to infinity. The robustness of these statistics against departure from normality will be assessed.Essentially, in the asymptotic spirit of this paper, both the hypothesis and error degrees of freedom tend to infinity at a fixed rate. It is intuitively appealing to consider asymptotics of this type because, for example, in random or mixed effects models, the levels of the main random factors are assumed to be a random sample from a large population of levels.For the asymptotic results of this paper to hold, we do not require any distributional assumption on the errors. That means the results can be used in real-life applications where normality assumption is not tenable.As it happens, the asymptotic distributions of the three statistics are normal. The statistics have been found to be asymptotically null robust against the departure from normality in the balanced designs. The expressions for the asymptotic means and variances are fairly simple. That makes the results an attractive alternative to the standard asymptotic results. These statements are favorably supported by the numerical results

Attractor Universe in the Scalar-Tensor Theory of Gravitation

In the scalar-tensor theory of gravitation it seems nontrivial to establish if solutions of the cosmological equations in the presence of a cosmological constant behave as attractors independently of the initial values. We develop a general formulation in terms of two-dimensional phase space. We show that there are two kinds of fixed points, one of which is an attractor depending on the coupling constant and equation of state. In the case with a power-law potential in the Jordan frame, we also find new type of inflation caused by the coupling to the matter fluid

ac Losses in a Finite Z Stack Using an Anisotropic Homogeneous-Medium Approximation

A finite stack of thin superconducting tapes, all carrying a fixed current I, can be approximated by an anisotropic superconducting bar with critical current density Jc=Ic/2aD, where Ic is the critical current of each tape, 2a is the tape width, and D is the tape-to-tape periodicity. The current density J must obey the constraint \int J dx = I/D, where the tapes lie parallel to the x axis and are stacked along the z axis. We suppose that Jc is independent of field (Bean approximation) and look for a solution to the critical state for arbitrary height 2b of the stack. For c<|x|<a we have J=Jc, and for |x|<c the critical state requires that Bz=0. We show that this implies \partial J/\partial x=0 in the central region. Setting c as a constant (independent of z) results in field profiles remarkably close to the desired one (Bz=0 for |x|<c) as long as the aspect ratio b/a is not too small. We evaluate various criteria for choosing c, and we show that the calculated hysteretic losses depend only weakly on how c is chosen. We argue that for small D/a the anisotropic homogeneous-medium approximation gives a reasonably accurate estimate of the ac losses in a finite Z stack. The results for a Z stack can be used to calculate the transport losses in a pancake coil wound with superconducting tape.Comment: 21 pages, 17 figures, accepted by Supercond. Sci. Techno

Artificial intelligence approaches to predicting and detecting cognitive decline in older adults: A conceptual review.

Preserving cognition and mental capacity is critical to aging with autonomy. Early detection of pathological cognitive decline facilitates the greatest impact of restorative or preventative treatments. Artificial Intelligence (AI) in healthcare is the use of computational algorithms that mimic human cognitive functions to analyze complex medical data. AI technologies like machine learning (ML) support the integration of biological, psychological, and social factors when approaching diagnosis, prognosis, and treatment of disease. This paper serves to acquaint clinicians and other stakeholders with the use, benefits, and limitations of AI for predicting, diagnosing, and classifying mild and major neurocognitive impairments, by providing a conceptual overview of this topic with emphasis on the features explored and AI techniques employed. We present studies that fell into six categories of features used for these purposes: (1) sociodemographics; (2) clinical and psychometric assessments; (3) neuroimaging and neurophysiology; (4) electronic health records and claims; (5) novel assessments (e.g., sensors for digital data); and (6) genomics/other omics. For each category we provide examples of AI approaches, including supervised and unsupervised ML, deep learning, and natural language processing. AI technology, still nascent in healthcare, has great potential to transform the way we diagnose and treat patients with neurocognitive disorders

Detection of a low-eccentricity and super-massive planet to the subgiant HD 38801

We report the detection of a large mass planet orbiting around the K0 metal-rich subgiant HD38801 ($V=8.26$) by precise radial velocity (RV) measurements from the Subaru Telescope and the Keck Telescope. The star has a mass of $1.36M_{\odot}$ and metallicity of [Fe/H]= +0.26. The RV variations are consistent with a circular orbit with a period of 696.0 days and a velocity semiamplitude of 200.0\mps, which yield a minimum-mass for the companion of 10.7\mjup and semimajor axis of 1.71 AU. Such super-massive objects with very low-eccentricities and hundreds of days period are uncommon among the ensemble of known exoplanets

Gravitational scalar field coupled directly to the Maxwell field and its effect to solar-system experiments

The effect of the massless gravitational scalar field assumed to couple directly to the Maxwell field to the solar-system experiments is estimated. We start with discussing the theoretical significances of this coupling. Rather disappointingly, however, we find that the scalar-field parameters never affect the observation in the limit of the geometric optics, indicating a marked difference from the well-known contribution through the spacetime metric.Comment: LaTex 10 page

Arf6 Controls Platelet Spreading and Clot Retraction via Integrin α\u3csub\u3eIIb\u3c/sub\u3eβ\u3csub\u3e3\u3c/sub\u3e Trafficking

Platelet and megakaryocyte endocytosis is important for loading certain granule cargo (ie, fibrinogen [Fg] and vascular endothelial growth factor); however, the mechanisms of platelet endocytosis and its functional acute effects are understudied. Adenosine 5\u27-diphosphate–ribosylation factor 6 (Arf6) is a small guanosine triphosphate–binding protein that regulates endocytic trafficking, especially of integrins. To study platelet endocytosis, we generated platelet-specific Arf6 knockout (KO) mice. Arf6 KO platelets had less associated Fg suggesting that Arf6 affects αIIbβ3-mediated Fg uptake and/or storage. Other cargo was unaffected. To measure Fg uptake, mice were injected with biotinylated- or fluorescein isothiocyanate (FITC)–labeled Fg. Platelets from the injected Arf6 KO mice showed lower accumulation of tagged Fg, suggesting an uptake defect. Ex vivo, Arf6 KO platelets were also defective in FITC-Fg uptake and storage. Immunofluorescence analysis showed initial trafficking of FITC-Fg to a Rab4-positive compartment followed by colocalization with Rab11-positive structures, suggesting that platelets contain and use both early and recycling endosomes. Resting and activated αIIbβ3 levels, as measured by flow cytometry, were unchanged; yet, Arf6 KO platelets exhibited enhanced spreading on Fg and faster clot retraction. This was not the result of alterations in αIIbβ3 signaling, because myosin light-chain phosphorylation and Rac1/RhoA activation were unaffected. Consistent with the enhanced clot retraction and spreading, Arf6 KO mice showed no deficits in tail bleeding or FeCl3-induced carotid injury assays. Our studies present the first mouse model for defining the functions of platelet endocytosis and suggest that altered integrin trafficking may affect the efficacy of platelet function

The dynamic exponent of the Ising model on negatively curved surfaces

We investigate the dynamic critical exponent of the two-dimensional Ising model defined on a curved surface with constant negative curvature. By using the short-time relaxation method, we find a quantitative alteration of the dynamic exponent from the known value for the planar Ising model. This phenomenon is attributed to the fact that the Ising lattices embedded on negatively curved surfaces act as ones in infinite dimensions, thus yielding the dynamic exponent deduced from mean field theory. We further demonstrate that the static critical exponent for the correlation length exhibits the mean field exponent, which agrees with the existing results obtained from canonical Monte Carlo simulations.Comment: 14 pages, 3 figures. to appear in J. Stat. Mec

A Substellar Companion in a 1.3 yr Nearly-circular Orbit of HD 16760

We report the detection of a substellar companion orbiting the G5 dwarf HD 16760 from the N2K sample. Precise Doppler measurements of the star from Subaru and Keck revealed a Keplerian velocity variation with a period of 466.47+-0.35 d, a semiamplitude of 407.71+-0.84 m/s, and an eccentricity of 0.084+-0.003. Adopting a stellar mass of 0.78+-0.05 M_Sun, we obtain a minimum mass for the companion of 13.13+-0.56 M_JUP, which is close to the planet/brown-dwarf transition, and the semimajor axis of 1.084+-0.023 AU. The nearly circular orbit despite the large mass and intermediate orbital period makes this companion unique among known substellar companions.Comment: 14 pages, 2 figures, accepted for publication in Ap