Searches for the Vector-Like Quarks usually look for their signatures assuming they decay purely into Standard Model particles. In this paper, we explore one possible exotic decay of the Vector-Like Quark with electric charge +5/3, X5/3. We adopt a simplified model which allows X5/3 to decay into a doubly-charged scalar S++ which further decays into a pair of same-sign leptons. We implement, validate and recast a recent CMS search for top quark partners with charge +5/3 in the same-sign dilepton final state. Our recast analysis provides a stringent bound of about 1.54 TeV on the mass of X5/3 for a wide range of masses of S++, independent of the chirality of the relevant couplings.

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The Next Generation Safeguards Initiative Spent Fuel (NGSI-SF) project was established in 2009 by the U.S. Departmentof Energy with main objective to investigate, and potentially develop and test new technologies for spent nuclearfuel (SNF) characterization. In Sweden the SNF is currently being considered to be verified and encapsulated in canistersand deposited into a geological repository. The need for an independent instrument for SNF verification by theSwedish operator turned into the collaborative effort with NGSI-SF to develop an instrument for future deployment inSweden.One of the techniques investigated within this project is the differential die-away (DDA) technique, which followingthe theoretical investigation by means of high fidelity Monte Carlo simulations indicated the potential to be applied fordetermining of various spent fuel assembly (SFA) parameters.This work introduces the first deployable DDA instrument which was designed to be used for characterizing ofSwedish SFAs currently stored in the Central Interim Storage Facility for Spent Nuclear Fuel (Clab). All the instrumentcomponents relevant for DDA design functionality were evaluated to ensure reliable operation in Clab. Although mostof the components were tuned with special consideration given to concerns from the operator (The Spent Nuclear FuelandWaste Management Company) , several post-simulation modification of the design were made. These modificationsare described in this work.A complementary study of the detector responses to asymmetrically burned SFAs indicated a different detector responses,depending on which of the four different orientations was used to assay individual SFAs. This study illustratedthe sensitivity of detectors with respect to the SFA orientation if there is a strong burn-up gradient across the SFA andhence a strong asymmetry in isotopic distribution in the SFA. In addition, the study of asymmetry provided the informationon different operational scenarios of the DDA instrument. The DDA instrument may provide general informationabout the complete SFA as well as give local information about certain parts of the SFA.

I arbetet mot att begränsa de mänskligt orsakade klimatförändringarna förväntas solkraft ha en stor potential till att ersätta energi av fossilt ursprung. Utbyggnaden av solcellsanläggningar ökar starkt vilket medför mer intermittent energiproduktion, vilket även medför ett behov av att lagra energin under dess produktionsvariationer. Litium-jonbatterier har ett brett användningsområde med egenskaper lämpliga för både energilagring och till snabba effektuttag. Syftet i detta arbete var att undersöka potentialen av litium-jonbatterier för att reducera effektbehovet från elnätet samt att öka egenanvändningen av solel för industrifastigheter. Målet var att utforma en beräkningsmodell för att värdera de ekonomiska, energi- och klimatbesparande förutsättningarna av ett sådant system. En modell konstruerades i Microsoft Excel för att utvärderas av tre industrier i en fallstudie. Med hänsyn till industrins lastprofil dimensionerades en installation av solceller och ett batterisystem. Tre driftstrategier betraktades för nyttjandet av batteriernas energilagring, en där kapaciteten endast var avsatt för att reducera effekttoppar över en efterfrågad nivå. För den andra strategin använde batterisystemet dess kapacitet helt fritt för att minska mängden el köpt från elnätet och därmed maximera användningen av den egenproducerade solelen. En kombination av de två driftstrategierna, som dels säkerställde att effektuttaget från elnätet inte översteg en viss nivå samt ökade egenanvändningen av solel, utgjorde den avvägda åtgärden. Lastprofilens karaktäristik skiljde sig mellan de tre industrierna, varpå potentialen och lämpligheten för en solcells- och batterisystemsinstallation varierade. Industri A, vars lastprofil hade en låg baslast med korta och höga effekttoppar visade sig mest lämpad för ett kompletterande batterisystem. Det ökade egenanvändandet av solel med ytterligare 26,1% relativt ett system med endast solceller. För Industri B och Industri C, vars lastprofiler hade tätare mellan topparna, var förbättringen av ett batterisystem mindre, 13,2% respektive 2,8%. Solcellsanläggningen för dessa två fastigheter hade en hög egenanvändning av solelen, varpå den relativa förbättringen av batterisystemet var mindre. Dessa ansågs dock väl lämpad för solceller. Ett minskat behov av el från elnätet resulterade även i en minskad kostnad för el. För Industri A värderades reduceringen av de höga effekttopparna högre än en minskad energianvändning. För Industri B och Industri C var värdet högre att minska energiuttaget än att reducera effektuttaget från elnätet. Ett batterisystem visade sig inte vara ekonomiskt lönsamt utifrån den nuvarande prisbilden. Den ekonomiska återbetalningstiden är i nuläget för lång, vilket kan ändras med sjunkande priser som en följd av en växande marknad. Klimatmässigt skedde största utsläppsminskningen av att solceller installerades, relativt då systemet kompletterades med batterier. Detta till följd av att ökningen av solelens egenanvändning med batterier var relativt liten den som endast solcellerna stod för. Batterisystem, liksom andra energilagringstekniker, kan få en betydande roll för att jämna ut elnätets belastning i framtiden i och med att en ökad andel intermittent elproduktion väntas.

Studies of nuclei far from stability offers new insights into the complete nucleon many-body problem. In nuclei with equal neutron and proton numbers (N=Z), the unique nature of the atomic nucleus as an object composed of two distinct types of fermions can be expressed as enhanced correlations arising between neutrons and protons occupying orbitals with the same quantum numbers. Such correlations have since several decades been predicted to favour a new type of nuclear superfluidity; isoscalar neutron-proton pairing, in addition to normal isovector pairing which dominates the structure of most known nuclei. Despite many experimental efforts these predictions have not been confirmed. The N=Z nuclei with mass number A>90 can only be produced in the laboratory at very low cross sections. The related problems of identifying and distinguishing such reaction products and their associated gamma rays from the vast array of N>Z nuclei that are present in much greater numbers have prevented observation of their low-lying excited states until recently. In the present work the experimental difficulties of observation of excited states in the N=Z=46 nucleus 92Pd have been overcome through the use of a highly efficient, state-of-the-art detector system and a prolonged experimental running period. The lowest excited states in 92Pd was empirically observed via detection of gamma rays emitted in the fusion-evaporation reaction together with detection of charged particles and neutrons in the ancillary detector system. The level spacings in the ground state band of 92Pd give the first experimental evidence for a new spin-aligned neutron-proton (np) paired phase. These findings reconcile with nuclear shell model calculations which predicts an unexpected effect of enhanced np correlations for N=Z nuclei in the immediate vicinity of the doubly magic nucleus 100Sn. Excited states of the odd-odd nucleus 162Ta have been observed using the JUROGAM/RITU experimental set-up. This nucleus is located in a transitional region in the nuclide chart which is between near-spherical nuclei and well-deformed nuclei, offering the possibility to study the emergence of collective phenomena and nuclear deformation (in particular the degree of triaxiality). The results, which are interpreted in the framework of the cranked shell model with total Routhian surface calculations suggest an almost axially symmetric nuclear shape. The energy staggering between the signature partners of the yrast rotational bands has been deduced for eight odd-odd isotopes in the neighborhood of 162Ta nucleus and the special observed feature of signature inversion for these nuclei is discussed. / QC 20111212

Measuring the dynamics of a quantum bit (qubit) relies on the accurate detection of the quantum state of the system. A widely used method to measure the state of a solid state Josephson junction qubit is to measure the switching current of a Josephson device. This work investigates the measurement of the switching current of SQUID samples by means of fast current pulses. The response of a SQUID to a square current pulse has to be measured at the top of a dilution refrigerator through long cables, resulting in bandwidth limitations. A switch in the last instance of a pulse will not be detected, resulting in uncertainties in the detection. We explain how a square bias pulse that is directly followed by a hold level of lower amplitude can be used to circumvent the bandwidth limitations by latching the state of the system it was in after the bias pulse. This corresponds to a sample and hold measurement. Every single measurement in a quantum mechanical probability measurement has to be statistically independent. We show correlation measurements for di erent settings of the pulse parameters and at di erent magnitudes of the switching current. A gure of merit for a quantum detector is its resolution. The measurements show that with the sample and hold technique good current resolutions can be obtained, even at very small magnitudes and short pulse durations. In order to make a fast measurement of the switching current, the switching process must occur during the bias pulse. We show in both measurements and computer simulations that a fast switch pulse can induce switching by the hold level,even when the hold level was initially adjusted to a value where it never switched the sample. The computer simulations show that by choosing the hold amplitude low enough, switching occurs rapidly, determined by the bias pulse alone.

Abstract: In this review, we referred to several recent works about the black-hole amplitudes. By regarding the black holes as elementary particles, we wrote down the amplitudeswhich describe the black-hole graviton scattering. Since gravitons are considered to be verysoft with respect to the black-hole particles, we expanded the dynamical variables (such asspinors, polarizations, and Dirac spinors) of the outgoing black hole around those of theincoming black hole. Then we expressed the amplitudes by using the spin vectors (PauliLubanski vectors) instead of spinors or polarizations. Finally, we compared the amplitudeswith the classical black-hole scattering computation.

Nitride fuels have gained a new interest in the last few years as both a candidate for GEN IV reactors and as accident tolerant fuels for current light water reactors. They however are decades behind oxide fuels when it comes to qualication and development of tools to assess their performances. In this thesis, such a tool is developed. The fuel performance codeTRANSURANUS, which has very good results with oxide fuels, is extended to handle nitride fuels. The relevant thermo-mechanical properties are implemented and fuel type dependent modules are updated. Their limitations and discrepancies are discussed. A particular attention is brought to the athermal ssion gas release, and a new model based on the open fabrication porosity is developed and added to the code, as a starting point toward a mechanistic model. It works well on oxide fuels, but its eciency is harder to evaluate for nitride fuels, due to large uncertainties on many key correlations such as the thermal conductivity and the eective diusion coecient of gas atoms. Recommendations are made to solve the most important problems. / <p>QC 20150604</p>

The non-destructive testing method Pulsed Eddy Current, or PEC, can be used to measure the thickness and resistivity of conducting and non-ferromagnetic materials. In this project I investigated if a gauge at ABB, which uses PEC technology to measure the thickness of aluminium strips in rolling mills, can extract more information about the strip by sampling the direct signal with a higher resolution than before. Using the gauge with this new sampling method, I first compared the noise level of the integrated signal obtained by using analog and digital integration. Then I used an upper noise level limit to determine how thick the strips could be without the noise level being too high. Finally, I used simulations and measurements of clad strips to determine if more information, such as the resistivity distribution, can be extracted from the measured signal and if the sampling frequency is high enough to detect the information. I found that the noise level can be reduced by replacing an analog integrator with a low-pass filter and integrating the signal digitally. I also found that the thickness can be between 1.3 mm and 12 mm whereas it can be between 0.50 mm and 8.0 mm with the previous sampling method. Finally, I found that the sampling frequency is high enough and that it is possible to determine if a strip has a clad layer or not. The results in this project suggest that it is beneficial to change the way the signal is sampled to this new method.

No description available.