Dark sectors 2016 Workshop: community report

This report, based on the Dark Sectors workshop at SLAC in April 2016, summarizes the scientific importance of searches for dark sector dark matter and forces at masses beneath the weak-scale, the status of this broad international field, the important milestones motivating future exploration, and promising experimental opportunities to reach these milestones over the next 5-10 years

Dark matter effective field theory scattering in direct detection experiments

We examine the consequences of the effective field theory (EFT) of dark matter–nucleon scattering for current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. We demonstrate that spectral differences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. We also discuss the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.National Science Foundation (U.S.)United States. Dept. of EnergyNatural Sciences and Engineering Research Council of CanadaSpain. Ministerio de Economia y Competitividad (MultiDark

Improved WIMP-search reach of the CDMS II germanium data

CDMS II data from the five-tower runs at the Soudan Underground Laboratory were reprocessed with an improved charge-pulse fitting algorithm. Two new analysis techniques to reject surface-event backgrounds were applied to the 612 kg days germanium-detector weakly interacting massive particle (WIMP)-search exposure. An extended analysis was also completed by decreasing the 10 keV analysis threshold to ~5  keV, to increase sensitivity near a WIMP mass of 8  GeV/c[superscript 2]. After unblinding, there were zero candidate events above a deposited energy of 10 keV and six events in the lower-threshold analysis. This yielded minimum WIMP-nucleon spin-independent scattering cross-section limits of 1.8 × 10[superscript −44] and 1.18 × 10[superscript −41] at 90% confidence for 60 and 8.6  GeV/c[superscript 2] WIMPs, respectively. This improves the previous CDMS II result by a factor of 2.4 (2.7) for 60 (8.6)  GeV/c[superscript 2] WIMPs.National Science Foundation (U.S.)United States. Dept. of EnergyNatural Sciences and Engineering Research Council of CanadaSpain. Ministerio de Economia y Competitividad (MultiDark

New Results from the Search for Low-Mass Weakly Interacting Massive Particles with the CDMS Low Ionization Threshold Experiment

The CDMS low ionization threshold experiment (CDMSlite) uses cryogenic germanium detectors operated at a relatively high bias voltage to amplify the phonon signal in the search for weakly interacting massive particles (WIMPs). Results are presented from the second CDMSlite run with an exposure of 70 kg day, which reached an energy threshold for electron recoils as low as 56 eV. A fiducialization cut reduces backgrounds below those previously reported by CDMSlite. New parameter space for the WIMP-nucleon spin-independent cross section is excluded for WIMP masses between 1.6 and 5.5  GeV/c[superscript 2].National Science Foundation (U.S.)United States. Dept. of EnergyFermi National Accelerator Laboratory (Visiting Scholar Award 13-S-04

Ratten in virtuellen Umgebungen: die Entwicklung einer neuartigen Methode um Tierverhalten zu untersuchen

A new setup was developed which allows us to let animals respectively rats interact with a virtual environment. This work describes the development of this setup from the first animal experiments towards an elaborated task on spatial behaviour. A cronological description of the experiments that have been performed with this setup gives an overview of the sucesses and failures that occoured when a new method is developed. The process of trial und error that leads to a helpfull tool to investigate animal behaviour is described here. Not only is here one of the first succesfull attempts described in which rodents interact whit a virtual environment in a way that true spatial behaviour is apparent, we could also succed with an attemp to combine this method with electrophysiological techiques.Ein neuentwichkelter Versuchsaufbau erlaubt es uns Tiere oder im engeren Sinne Ratten mit virtuellen Umgebungen interagieren zu lassen. Die hier vorgestellte Arbeit beschreibt die Entwicklung dieses Aufbaus vom ersten Experiment bis hin zur erfoglreichen virtuellen Umsetzung eines standard Versuchs zur räumlichen Orientierung. Die mit diesen Versuchsaufbau durchgeführten Experimente werden in chronologischer Abfolge dargestellt und geben einen Eindruck von den Erfolgen und Fehlern die bei der Entwichlung einer neuartigen Methode auftreten können. Es ist hier nicht nur einer der ersten erfolgreichen Versuche beschrieben in dem Ratten eine echte räumliche Interakion mit einer simulierten Umgebung zeigen, es ist uns weiterhin gelungen diese Methode mit electrophysiologischen Techniken zu kombinieren

Effective attenuation length for lanthanum lutetium oxide between 7 and 13 keV

To obtain quantitative depth information from hard X-ray photoemission spectroscopy, the effective attenuation length (EAL) is required. In this paper, the EAL was determined for LaLuO3 for electron kinetic energies between 7 and 13 keV. As a result, the EAL is in the range of 100–150A ° for the investigated photon energies. In addition, higher binding energy orbitals of La and Lu were measured and are discussed. LaLuO3 is a promising high-k dielectric for future nano-scaled MOS devices

Mechanism Transitions: A New Paradigm for a Highly Adaptive Internet

The Internet faces ever faster and stronger dynamics in the behavior patterns of its users and hence, in the imposed load and traffic. However, the various ‘mechanisms’ used within the Internet—communication protocols and their functional components, overlays, middleware, etc.—cannot be sufficiently adapted at runtime: parameter adaptation is common practice, but the replacement of a mechanism by one that is functionally similar yet more appropriate—for the benefit of performance and quality—is rare. Those rare cases are tediously engineered case by case since on-the-fly transitions between similar mechanisms are not promoted by today’s Internet construction principles. In light of the considerations above, the present whitepaper advocates mechanism transitions as a fundamental new principle for the Internet and makes inroads into its modeling and specification. The quest for a fundamentally more flexible Internet is not only fueled by trends regarding users and applications ‘above’, but also by innovations in the network technology ‘below’: Software-defined systems and networks emerge as an enabling technology for more flexibility, but cannot be sufficiently leveraged for more flexibility in the Internet as a whole. The German Collaborative Research Center MAKI investigates appropriate models, concepts and methods as well as prerequisites and benefits in regard to mechanism transitions in the Future Internet. The present whitepaper comprises approaches to the modeling and specification of such mechanism transitions, both from a structural and a behavioral perspective, as developed over the last three years. The various other aspects of MAKI, such as investigations of particular sets of mechanism or monitoring and control aspects, are not covered here. The whitepaper starts by providing a more detailed discussion of the quest for Internet mechanism transitions and of related issues. It continues by introducing the basic MAKI architecture and terminology in comparison to those of the OSI standard and the Internet. In the sequel, different approaches to the general structural and behavioral modeling and specification of mechanism transitions are presented, as developed and used in MAKI. The presented research contributions were created with different purposes and focuses in mind; they represent important steps forward on our path towards a consolidated framework for mechanism transitions. In other words, they make inroads into a highly dynamic Future Internet that can cope with ever increasing dynamics. We will use terminology from the ISO OSI standard as a starting point for introducing our terms and concepts. For readers with limited knowledge in this underlying standard, we provide a short OSI terminology primer in the appendix

A helix-breaking mutation in TRPML3 leads to constitutive activity underlying deafness in the varitint-waddler mouse

Homozygote varitint-waddler (Va) mice, expressing a mutant isoform (A419P) of TRPML3 (mucolipin 3), are profoundly deaf and display vestibular and pigmentation deficiencies, sterility, and perinatal lethality. Here we show that the varitint-waddler isoform of TRPML3 carrying an A419P mutation represents a constitutively active cation channel that can also be identified in native varitint-waddler hair cells as a distinct inwardly rectifying current. We hypothesize that the constitutive activation of TRPML3 occurs as a result of a helix-breaking proline substitution in transmembrane-spanning domain 5 (TM5). A proline substitution scan demonstrated that the inner third of TRPML3's TM5 is highly susceptible to proline-based kinks. Proline substitutions in TM5 of other TRP channels revealed that TRPML1, TRPML2, TRPV5, and TRPV6 display a similar susceptibility at comparable positions, whereas other TRP channels were not affected. We conclude that the molecular basis for deafness in the varitint-waddler mouse is the result of hair cell death caused by constitutive TRPML3 activity. To our knowledge, our study provides the first direct mechanistic link of a mutation in a TRP ion channel with mammalian hearing loss