Higgsino Dark Matter in High-Scale Supersymmetry

We study a supersymmetric (SUSY) Standard Model in which a Higgsino is light enough to be dark matter, while the other SUSY particles are much heavier than the weak scale. We carefully treat the effects of heavy SUSY particles to the Higgsino nature, especially taking into account the renormalization effects due to the large hierarchy between the Higgsino and the SUSY breaking scales. Inelastic scattering of the Higgsino dark matter with a nucleus is studied, and the constraints on the scattering by the direct detection experiments are discussed. This gives an upper limit on the new physics scale. Bounds on the dark matter-nucleon elastic scattering, the electric dipole moments, and direct production of Higgsinos, on the other hand, give a lower limit. We show the current status on the limits and discuss the future prospects.Comment: 28 pages, 12 figures. Version accepted for publication in JHE

Electroweakly-Interacting Dirac Dark Matter

We consider a class of fermionic dark matter candidates that are charged under both the SU(2)$_L$ and U(1)$_Y$ gauge interactions. In this case a certain amount of dark matter-Higgs couplings, which can split the dark matter into a pair of Majorana fermions, should be present to evade the constraints from the dark matter direct detection experiments. These effects may be probed by means of the dark matter-nucleus scattering via the Higgs-boson exchange process, as well as the electric dipole moments induced by the dark matter and its SU(2)$_L$ partner fields. In this article, we evaluate them with an effective field approach. It turns out that the constraints coming from the experiments for the quantities have already restricted the dark matter with hypercharge $Y\geq 3/2$. Future experiments have sensitivities to probe this class of dark matter candidates, and may disfavor the $Y\geq 1$ cases if no signal is observed. In this case, only the $Y=0$ and $1/2$ cases may be the remaining possibilities for the SU(2)$_L$ charged fermionic dark matter candidates.Comment: 5 pages, 3 figure

Probing Bino-Wino Coannihilation at the LHC

We study bino-wino coannihilation scenario in the so-called spread or mini-split supersymmetry. We show that, in this model, a neutral wino has a macroscopic decay length in a wide range of parameter space. This characteristic feature could be observed as a displaced vertex plus missing transverse energy event at the LHC. In this paper, we study the current constraints and future prospects on the scenario based on the displaced vertex search performed by the ATLAS collaboration. It is found that a sizable parameter region can be probed at the 8 TeV LHC run. This search strategy will considerably extend its reach at the next stage of the LHC running, and thus play a crucial role to examine a possibility of bino dark matter in the mini-split type supersymmetric models.Comment: 21 pages, 7 figures; version accepted for publication in JHE

Higgsino Dark Matter or Not: Role of Disappearing Track Searches at the LHC and Future Colliders

Higgsino in supersymmetric standard models is known to be a promising candidate for dark matter in the Universe. Its phenomenological property is strongly affected by the gaugino fraction in the Higgsino-like state. If this is sizable, in other words, if gaugino masses are less than ${\cal O}(10)$ TeV, we may probe the Higgsino dark matter in future non-accelerator experiments such as dark matter direct searches and measurements of electric dipole moments. On the other hand, if gauginos are much heavier, then it is hard to search for Higgsino in these experiments. In this case, due to a lack of gaugino components, the mass difference between the neutral and charged Higgsinos is uniquely determined by electroweak interactions to be around $350$ MeV, which makes the heavier charged state rather long-lived, with a decay length of about $1$ cm. In this letter, we argue that a charged particle with a flight length of ${\cal O}(1)$ cm can be probed in disappearing-track searches if we require only two hits in the pixel detector. Even in this case, we can reduce background events with the help of the displaced-vertex reconstruction technique. We study the prospects of this search strategy at the LHC and future colliders for the Higgsino dark matter scenario. It is found that an almost pure Higgsino is indeed within the reach of the future $33$ TeV collider experiments. We then discuss that the interplay among collider and non-accelerator experiments plays a crucial role in testing the Higgsino dark matter scenarios. Our strategy for disappearing-track searches can also enlarge the discovery potential of pure wino dark matter as well as other electroweak-charged dark matter candidates.Comment: 7 pages, 3 figure

Influence of insulin injection on skin

Aims/Introduction: The influence of repeated insulin injection on subcutaneous tissue is known, but its impact on the skin is unclear. Therefore, this study aimed to elucidate the impact of repeated insulin injections on the skin. Material and Methods: The properties of the skin and the subcutaneous tissue were evaluated in 52 insulin-treated adult patients with diabetes with abnormal findings at the site of self-injection (36 with subcutaneous nodules, 16 with suspected subcutaneous tissue induration) by ultrasonography. In all subjects, both normal and abnormal areas were examined. In addition, skin biopsies were performed in four subjects. Results: The skin thickness of the normal and abnormal skin sites was 1.95 (1.60, 2.50) and 2.80 (2.27, 3.30) mm, respectively (median (first quartile, third quartile)), (P < 0.001). The biopsy specimens revealed slightly thickened and tight bundles of collagen in the dermis. Three patients had amyloid deposits in the subcutaneous tissue, and one also showed these in the dermis. These were positively stained for insulin antibody. Conclusions: Repeated insulin injection procedures result in skin thickening. Increased collagen fibers and possibly amyloid deposition in the dermis may be involved. The results reaffirmed the importance of appropriate site rotation in insulin injection and revealed the usefulness of ultrasonographic skin examination in evaluating the self-injection procedure

EFFECTS OF SCATTER IN BOLT PRELOAD ON THE SEALING PERFORMANCE IN BOLTED FLANGE CONNECTIONS WITH COVER OF PRESSURE VESSEL UNDER INTERNAL PRESSURE

ABSTRACT It has been well known that the scatter in axial bolt forces of bolted flange connections tightened by torque control methods is substantial. In evaluating the sealing performance of a bolted flange connection with a gasket subjected to internal pressure, it is necessary to know the contact gasket stress distributions due to the scatter of the axial bolt forces in the flange connections tightened by torque control methods. This paper deals with the leakage of a bolted flange connection with a cover of pressure vessel including a spiral wound gasket tightened by a torque wrench. The scatter in the axial bolt forces was measured using strain gauges attached at the shank of bolts. The amount of leakage from the bolted flange connection with cover of pressure vessel was measured by socalled pressure decay method. The gas employed was Helium. From the measured leakage, the actual assembly efficiency is examined. The eight bolts and nuts were tightened according to the ASME PCC-1 method and Japanese method developed by High Pressure Institute (HPI). The difference in the bolt preload was shown between the ASME method and the HPI method. The contact gasket stress distributions at the interface of the flange connection with the gasket were calculated under the measured axial bolt forces by means of finite element analysis. Using the calculated gasket contact stress distribution, the amount of gas leakage was estimated. The estimated gas leakage was compared with the measured results