250 research outputs found
Epistemic Cognition and Motivation
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
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
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
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
Two different simple measurements of galaxy star formation rate with
different timescales are compared empirically on fiber spectra of
galaxies with mag taken from the Sloan Digital Sky Survey in the
redshift range : 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 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 at redshift .
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
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
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
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
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 -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
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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