21,981 research outputs found

    Calorimetry for low-energy electrons using charge and light in liquid argon

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    Precise calorimetric reconstruction of 5–50 MeV electrons in liquid argon time projection chambers (LArTPCs) will enable the study of astrophysical neutrinos in DUNE and could enhance the physics reach of oscillation analyses. Liquid argon scintillation light has the potential to improve energy reconstruction for low-energy electrons over charge-based measurements alone. Here we demonstrate light-augmented calorimetry for low-energy electrons in a single-phase LArTPC using a sample of Michel electrons from decays of stopping cosmic muons in the LArIAT experiment at Fermilab. Michel electron energy spectra are reconstructed using both a traditional charge-based approach as well as a more holistic approach that incorporates both charge and light. A maximum-likelihood fitter, using LArIAT’s well-tuned simulation, is developed for combining these quantities to achieve optimal energy resolution. A sample of isolated electrons is simulated to better determine the energy resolution expected for astrophysical electron-neutrino charged-current interaction final states. In LArIAT, which has very low wire noise and an average light yield of 18  pe/MeV, an energy resolution of σ/E≃9.3%/√E⊕1.3% is achieved. Samples are then generated with varying wire noise levels and light yields to gauge the impact of light-augmented calorimetry in larger LArTPCs. At a charge-readout signal-to-noise of S/N≃30, for example, the energy resolution for electrons below 40 MeV is improved by ≈10%, ≈20%, and ≈40% over charge-only calorimetry for average light yields of 10  pe/MeV, 20  pe/MeV, and 100  pe/MeV, respectively.https://arxiv.org/abs/1909.07920Othe

    Emerging Markets in Water: A Comparative Institutional Analysis of the Central Valley and Colorado-Big Thompson Projects

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    Water trading is a potential means to improve the productivity of developed water supplies and reconcile competing uses. Economic theory suggests that markets evolve in response to changes in supply and demand. This prediction is at odds with observed disparities in the pace of market development in regions facing similar pressures on scarce water resources. A dramatic example of this disparity is found in the regions served by the California Central Valley Project and the Colorado-Big Thompson Project.This article argues that the differences in market activity in the two areas can be explained largely by the underlying water allocation institutions. The article identifies key institutional features that affect the transaction costs of water trading and examines the rootsof the institutional diferences. The institutions governing market transactions today are largely a function of pre-existing property rights and political battles to build consensus and obtain federal financing for the projects. The article highlights the path-dependent nature of water allocation institutions and trading, but also suggests that complex inter-regional markets could still develop in California given ever-increasing competition for scarce water resources and advances in information technology that lower market transaction costs

    Uplift Quadratic Program in Irish Electricity Price Setting

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    Bord Gis required a deeper insight into the dynamics of Uplift prices. The aim of the group was to apply a variety of analytical tools to the problem in order to satisfy Bord Gis requirements. The group conducted a KKT Optimality Analysis of the quadratic program used to determine the Uplift prices, performed statistical analysis to identify the binding constraints and their sensitives to the Uplift prices, simulated a synthetic stochastic process that is consistent with the Uplift pricing series and investigated alternative objective functions for the quadratic program

    The Risks of Financial Institutions

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    Over the last twenty years, the consensus view of systemic risk in the financial system that emerged in response to the banking crises of the 1930s and before has lost much of its relevance. This view held that the main systemic problem is runs on solvent banks leading to bank panics. But financial crises of the last two decades have not fit the mold. A new consensus has yet to emerge, but financial institutions and regulators have considerably broadened their assessment of the risks facing financial institutions. The dramatic rise of modern risk management has changed how the risks of financial institutions are measured and how these institutions are managed. However, modern risk management is not without weaknesses that will have to be addressed.

    Pairwise Well-Formed Modes and Transformations

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    One of the most significant attitudinal shifts in the history of music occurred in the Renaissance, when an emerging triadic consciousness moved musicians towards a new scalar formation that placed major thirds on a par with perfect fifths. In this paper we revisit the confrontation between the two idealized scalar and modal conceptions, that of the ancient and medieval world and that of the early modern world, associated especially with Zarlino. We do this at an abstract level, in the language of algebraic combinatorics on words. In scale theory the juxtaposition is between well-formed and pairwise well-formed scales and modes, expressed in terms of Christoffel words or standard words and their conjugates, and the special Sturmian morphisms that generate them. Pairwise well-formed scales are encoded by words over a three-letter alphabet, and in our generalization we introduce special positive automorphisms of F3F3, the free group over three letters.Comment: 12 pages, 3 figures, paper presented at the MCM2017 at UNAM in Mexico City on June 27, 2017, keywords: pairwise well-formed scales and modes, well-formed scales and modes, well-formed words, Christoffel words, standard words, central words, algebraic combinatorics on words, special Sturmian morphism
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