14,128 research outputs found

    Simplified SUSY at the ILC

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    At the ILC, one has the possibility to search for SUSY in an model-independent way: The corner-stone of SUSY is that sparticles couple as particles. This is independent of the mechanism responsible for SUSY breaking. Any model will have one Lightest SUSY Particle (LSP), and one Next to Lightest SUSY Particle (NLSP). In models with conserved R-parity, the NLSP must decay solely to the LSP and the SM partner of the NLSP. Therefore, studying NLSP production and decay can be regarded as a "simplified model without simplification": Any SUSY model will have such a process. The NLSP could be any sparticle: a slepton, an electroweak-ino, or even a squark. However, since there are only a finite number of sparticles, one can systematically search for signals of all possible NLSP:s. This way, the entire space of models that have a kinematicall y reachable NLSP can be covered. For any NLSP, the "worst case" can be determined, since the SUSY principle allows to calculate the cross-section once the NLSP nature and mass are given. The region in the LSP-NLSP mass-plane where the "worst case" could be discovered or excluded experimentally can be found by estimating background and efficiency at each point in the plane. From experience at LEP, it is expected that the lower signal-to background ratio will indeed be found for models with conserved R-parity. In this document, we show that at the ILC, such a program is possible, as it was at LEP. No loop-holes are left, even for difficult or non-standard cases: whatever the NLSP is it will be detectable.Comment: Whitepaper contributed to Snowmass Community Summer Study 2013. 11 pages, 5 figure

    The Frailty of Economic Reforms: Political Logic and Constitutional Lessons

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    Why are efficiency-enhancing reforms often frail and subject to being undermined over time? Two theories are examined: public-choice theory, which explains this as the possible result of a need, from time to time, to wipe the slate clean in order to retain productivity in the distribution of favors to interest groups, and a theory which acknowledges that politicians may implement reforms for ideological reasons but still, as time passes, be influenced by the logic of the political and media systems to abandon their initial aspirations. In any case, the demise of reforms is partly a function of the constitutional setting: rules which encourage shortsightedness and easy satisfaction of interest-group agendas make it difficult for decision-makers to withstand pressure for legislative change. Avenues to mitigate these problems through constitutional reforms are explored.tax reform; political incentives; constitutional reform

    Time for behavioral political economy? An analysis of articles in behavioral economics

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    This study analyzes leading research in behavioral economics to see whether it contains advocacy of paternalism and whether it addresses the potential cognitive limitations and biases of the policymakers who are going to implement paternalist policies. The findings reveal that 20.7% of the studied articles in behavioral economics propose paternalist policy action and that 95.5% of these do not contain any analysis of the cognitive ability of policymakers. This suggests that behavioral political economy, in which the analytical tools of behavioral economics are applied to political decision-makers as well, would offer a useful extension of the research program.Behavioral economics; Anomalies; Rationality; Homo economicus; Public choice

    Does Belief in Ethical Subjectivism Pose a Challenge to Classical Liberalism?

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    Classical liberalism stresses the desirability of free markets, limited government and the rule of law. As such, it builds on some moral judgments. According to ethical objectivism, such judgments (in themselves always personal and subjective) can be true or false since objective moral facts exist against which the judgments can be assessed. Ethical subjectivism denies the existence of objective moral facts. This paper asks: Does it matter whether people believe that objective moral facts exist – in general and for a defense of classical liberalism? It is argued that the answer is in the negative. The implication for classical liberal strategy is that attempts to argue that a certain metaethical foundation is needed should be abandoned.metaethics; liberalism; values

    Algae from the inland ice of Greenland. [Translation from: Kongl.Vetenskaps-Akademiens Forhandlingar 1871(2) 293-296, 1871.]

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    On the large inland ice cover of Greenland, where the temperature even during the short summer, falls below freezing some time during the daily 24 hours, it is still possible to find organic life. The author found in melted ice water several species of algae on his ”walk” in the latter part of July 1870. The article describes the finds and tries to identify the algae to family level

    Spin Inelastic Electron Tunneling Spectroscopy on Local Magnetic Moment Embedded in Josephson Junction

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    Recent experimental conductance measurements performed on paramagnetic molecular adsorbates on a superconducting surface, using superconducting scanning tunneling microscopy techniques, are theoretically investigated. For low temperatures, we demonstrate that tunneling current assisted excitations of the local magnetic moment cannot occur for voltage biases smaller than the superconducting gap of the scanning tunneling microscope. The magnetic moment is only excited for voltages corresponding to the sum of the superconducting gap and the spin excitation energies. In excellent agreement with experiment, we show that pumping into higher excitations give additional current signatures by accumulation of density in the lower ones. Using external magnetic fields, we Zeeman split possible degeneracy and thereby resolve all excitations comprised in the magnetic moment.Comment: 6 pages, 4 figures, submitte

    Electron Paramagnetic Resonance of Single Magnetic Moment on a Surface

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    We address electron spin resonance of single magnetic moments in a tunnel junction using time-dependent electric fields and spin-polarized current. We show that the tunneling current directly depends on the local magnetic moment and that the frequency of the external electric field mixes with the characteristic Larmor frequency of the local spin. The importance of the spin-polarized current induced anisotropy fields acting on the local spin moment is, moreover, demonstrated. Our proposed model thus explains the absence of an electron spin resonance for a half integer spin, in contrast with the strong signal observed for an integer spin.Comment: 6 pages, 2 figures, as publishe
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