250 research outputs found

    Epistemic Cognition and Motivation

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    Why do you want to teach? What are the reasons you decided to major in philosophy in college? Why did you consult three different physicians and comb through hundreds of medical journals just to find out whether you should have your daughter vaccinated—isn’t asking your own doctor sufficient? Motivation is at the root of all of these types of questions. Motivation researchers are primarily concerned with the cognitive processes by which people initiate and sustain behaviors. For example, if a group of teachers indicate they decided to teach because they believe ensuring the next generation of young people enters their adult lives prepared to face the challenges of the 21st century, then these teachers are likely describing a belief in the utility of what they do. On the other hand, if a student said she decided to major in philosophy because she took introductory courses in logic and in ethics and earned superior marks in these classes, then her competence beliefs are likely the most salient aspect of her motivation. Although motivation historically has been presented in many different ways (e.g., need satisfaction, innate drives), in this chapter we frame the most commonly studied constructs of motivation as important cognitive structures and processes that guide our behaviors. We conceive of behaviors in a broad sense of the word to also include cognitive behaviors such as asking oneself whether a certain strategy is the best approach to solve a problem. This focus is in line with the purpose of this chapter and handbook—to focus on cognitive structures and processes that guide behaviors related specifically to building and evaluating knowledge. Given this focus on the cognitive basis of motivation, we then explore how motivational aspects of cognition relate to aspects of cognition that concern the nature of knowledge and knowing. Although the literature about the intersection of motivation and epistemic cognition is relatively small, scholars are becoming increasingly interested in questions such as, “why might some students refer to a politician about whether vaccines are effective and safe rather than refer to their family doctor?” At the heart of these types of questions is the assumption that cognitive behavior (including epistemic cognition) is motivated. That is, might some students refer to their teachers as the definitive source for an answer because they believe that it is not worth the time and effort to find more nuanced answers from multiple sources of information? Or might other students seek out alternative answers that are different from their textbook because they want to show off to their peers and teachers about how smart they are? To understand the linkages between motivation and epistemic cognition, however, we must first understand the theoretical frameworks that guide research in motivation as well as the empirical findings that have supported them. Motivation is a very broad construct that can include competence beliefs (i.e., “Am I able to do this task?”), value beliefs (i.e., “Do I find this task compelling?”), and goal orientations (i.e., “What is the reason I am engaging in this task?”). Given the large number of constructs included under the umbrella term of motivation, clarification is necessary regarding which constructs are typically included when researchers describe motivation. From there, we explore the studies that have examined the links between epistemic cognition and motivation, we consider ways that theory on epistemic cognition has implicitly enveloped motivational constructs, and we delineate how clear motivational constructs might inform such research. We conclude by exploring areas where future research is needed, and offer comments about the types of studies that may be productive for the field.https://scholarworks.wm.edu/bookchapters/1001/thumbnail.jp

    Diagnosing Spin at the LHC via Vector Boson Fusion

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    We propose a new technique for determining the spin of new massive particles that might be discovered at the Large Hadron Collider. The method relies on pair-production of the new particles in a kinematic regime where the vector boson fusion production mechanism is enhanced. For this regime, we show that the distribution of the leading jets as a function of their relative azimuthal angle can be used to distinguish spin-0 from spin-1/2 particles. We illustrate this effect by considering the particular cases of (i) strongly-interacting, stable particles and (ii) supersymmetric particles carrying color charge. We argue that this method should be applicable in a wide range of new physics scenarios.Comment: 5 pages, 4 figure

    Vacuum Stability, Perturbativity, and Scalar Singlet Dark Matter

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    We analyze the one-loop vacuum stability and perturbativity bounds on a singlet extension of the Standard Model (SM) scalar sector containing a scalar dark matter candidate. We show that the presence of the singlet-doublet quartic interaction relaxes the vacuum stability lower bound on the SM Higgs mass as a function of the cutoff and lowers the corresponding upper bound based on perturbativity considerations. We also find that vacuum stability requirements may place a lower bound on the singlet dark matter mass for given singlet quartic self coupling, leading to restrictions on the parameter space consistent with the observed relic density. We argue that discovery of a light singlet scalar dark matter particle could provide indirect information on the singlet quartic self-coupling.Comment: 25 pages, 10 figures; v2 - fixed minor typos; v3 - added to text discussions of other references, changed coloring of figures for easier black and white viewin

    Neutral currents and tests of three-neutrino unitarity in long-baseline experiments

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    We examine a strategy for using neutral current measurements in long-baseline neutrino oscillation experiments to put limits on the existence of more than three light, active neutrinos. We determine the relative contributions of statistics, cross section uncertainties, event misidentification and other systematic errors to the overall uncertainty of these measurements. As specific case studies, we make simulations of beams and detectors that are like the K2K, T2K, and MINOS experiments. We find that the neutral current cross section uncertainty and contamination of the neutral current signal by charge current events allow a sensitivity for determining the presence of sterile neutinos at the 0.10--0.15 level in probablility.Comment: 24 pages, Latex2e, uses graphicx.sty, 2 postscript figures. Submitted to the Neutrino Focus Issue of New Journal Physics at http://www.njp.or

    Selection and photometric properties of K+A galaxies

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    Two different simple measurements of galaxy star formation rate with different timescales are compared empirically on 156,395156,395 fiber spectra of galaxies with r<17.77r<17.77 mag taken from the Sloan Digital Sky Survey in the redshift range 0.05<z<0.200.05<z<0.20: a ratio \Aamp / \Kamp found by fitting a linear sum of an average old stellar poplulation spectrum (\Kamp) and average A-star spectrum (\Aamp) to the galaxy spectrum, and the equivalent width (EW) of the \Halpha emission line. The two measures are strongly correlated, but there is a small clearly separated population of outliers from the median correlation that display excess \Aamp /\Kamp relative to \Halpha EW. These ``K+A'' (or ``E+A'') galaxies must have dramatically decreased their star-formation rates over the last 1\sim 1 Gyr. The K+A luminosity distribution is very similar to that of the total galaxy population. The K+A population appears to be bulge-dominated, but bluer and higher surface-brightness than normal bulge-dominated galaxies; it appears that K+A galaxies will fade with time into normal bulge-dominated galaxies. The inferred rate density for K+A galaxy formation is 104h3Mpc3Gyr1\sim 10^{-4} h^3 Mpc^{-3} Gyr^{-1} at redshift z0.1z\sim 0.1. These events are taking place in the field; K+A galaxies don't primarily lie in the high-density environments or clusters typical of bulge-dominated populations.Comment: submitted to Ap

    Potential of optimized NOvA for large theta(13) & combined performance with a LArTPC & T2K

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    NOvA experiment has reoptimized its event selection criteria in light of the recently measured moderately large value of theta(13). We study the improvement in the sensitivity to the neutrino mass hierarchy and to leptonic CP violation due to these new features. For favourable values of deltacp, NOvA sensitivity to mass hierarchy and leptonic CP violation is increased by 20%. Addition of 5 years of neutrino data from T2K to NOvA more than doubles the range of deltacp for which the leptonic CP violation can be discovered, compared to stand alone NOvA. But for unfavourable values of deltacp, the combination of NOvA and T2K are not enough to provide even a 90% C.L. hint of hierarchy discovery. Therefore, we further explore the improvement in the hierarchy and CP violation sensitivities due to the addition of a 10 kt liquid argon detector placed close to NOvA site. The capabilities of such a detector are equivalent to those of NOvA in all respects. We find that combined data from 10 kt liquid argon detector (3 years of nu + 3 years of nubar run), NOvA (6 years of nu + 6 years of nubar run) and T2K (5 years of nu run) can give a close to 2 sigma hint of hierarchy discovery for all values of deltacp. With this combined data, we can achieve CP violation discovery at 95% C.L. for roughly 60% values of deltacp.Comment: 22 pages, 24 pdf figures, 5 tables. In the appendix, new results are presented with conservative choices of central values of oscillation parameters. New references are added. Accepted in JHE

    A Pharmacology-Based Enrichment Program for Undergraduates Promotes Interest in Science

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    There is a strong need to increase the number of undergraduate students who pursue careers in science to provide the “fuel” that will power a science and technology–driven U.S. economy. Prior research suggests that both evidence-based teaching methods and early undergraduate research experiences may help to increase retention rates in the sciences. In this study, we examined the effect of a program that included 1) a Summer enrichment 2-wk minicourse and 2) an authentic Fall research course, both of which were designed specifically to support students\u27 science motivation. Undergraduates who participated in the pharmacology-based enrichment program significantly improved their knowledge of basic biology and chemistry concepts; reported high levels of science motivation; and were likely to major in a biological, chemical, or biomedical field. Additionally, program participants who decided to major in biology or chemistry were significantly more likely to choose a pharmacology concentration than those majoring in biology or chemistry who did not participate in the enrichment program. Thus, by supporting students\u27 science motivation, we can increase the number of students who are interested in science and science careers

    Electron neutrino tagging through tertiary lepton detection

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    We discuss an experimental technique aimed at tagging electron neutrinos in multi-GeV artificial sources on an event-by-event basis. It exploits in a novel manner calorimetric and tracking technologies developed in the framework of the LHC experiments and of rare kaon decay searches. The setup is suited for slow-extraction, moderate power beams and it is based on an instrumented decay tunnel equipped with tagging units that intercept secondary and tertiary leptons from the bulk of undecayed \pi^+ and protons. We show that the taggers are able to reduce the \nue contamination originating from K_e3 decays by about one order of magnitude. Only a limited suppression (~60%) is achieved for \nue produced by the decay-in-flight of muons; for low beam powers, similar performance as for K_e3 can be reached supplementing the tagging system with an instrumented beam dump.Comment: 19 pages, 7 figures; minor changes, version to appear in EPJ

    Atmospheric neutrino observations and flavor changing interactions

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    Flavor changing (FC) neutrino-matter interactions can account for the zenith-angle dependent deficit of atmospheric neutrinos observed in the SuperKamiokande experiment, without directly invoking neither neutrino mass, nor mixing. We find that FC νμ\nu_\mu-matter interactions provide a good fit to the observed zenith angle distributions, comparable in quality to the neutrino oscillation hypothesis. The required FC interactions arise naturally in many attractive extensions of the Standard Model.Comment: RevTex, 4 pages, 2 postscript figures, some minor modifications in the text and few new references are added, no change in the results and conclusions, final version to be published in Phys. Rev. Let

    Invisible Z-Boson Decays at e+e- Colliders

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    The measurement of the invisible Z-boson decay width at e+e- colliders can be done "indirectly", by subtracting the Z-boson visible partial widths from the Z-boson total width, or "directly", from the process e+e- -> \gamma \nu \bar{\nu}. Both procedures are sensitive to different types of new physics and provide information about the couplings of the neutrinos to the Z-boson. At present, measurements at LEP and CHARM II are capable of constraining the left-handed Z\nu\nu-coupling, 0.45 <~ g_L <~ 0.5, while the right-handed one is only mildly bounded, |g_R| <= 0.2. We show that measurements at a future e+e- linear collider at different center-of-mass energies, \sqrt{s} = MZ and \sqrt{s}s ~ 170 GeV, would translate into a markedly more precise measurement of the Z\nu\nu-couplings. A statistically significant deviation from Standard Model predictions will point toward different new physics mechanisms, depending on whether the discrepancy appears in the direct or the indirect measurement of the invisible Z-width. We discuss some scenarios which illustrate the ability of different invisible Z-boson decay measurements to constrain new physics beyond the Standard Model
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