Precision Tests of Parity Violation Over Cosmological Distances

Recent measurements of the Cosmic Microwave Background $B$-mode polarization power spectrum by the BICEP2 and POLARBEAR experiments have demonstrated new precision tools for probing fundamental physics. Regardless of origin, the fact that we can detect sub-$\mu$K CMB polarization represents a tremendous technological breakthrough. Yet more information may be latent in the CMB's polarization pattern. Because of its tensorial nature, CMB polarization may also reveal parity-violating physics via a detection of cosmic polarization rotation. Although current CMB polarimeters are sensitive enough to measure one degree-level polarization rotation with $>5\sigma$ statistical significance, they lack the ability to differentiate this effect from a systematic instrumental polarization rotation. Here, we motivate the search for cosmic polarization rotation from current CMB data as well as independent radio galaxy and quasar polarization measurements. We argue that an improvement in calibration accuracy would allow the precise measurement of parity- and Lorentz-violating effects. We describe the CalSat space-based polarization calibrator that will provide stringent control of systematic polarization angle calibration uncertainties to $0.05^\circ$ -- an order of magnitude improvement over current CMB polarization calibrators. CalSat-based calibration could be used with current CMB polarimeters searching for $B$-mode polarization, effectively turning them into probes of cosmic parity violation, i.e. without the need to build dedicated instruments.Comment: 11 pages, 3 figure

Cooling a single atom in an optical tweezer to its quantum ground state

We report cooling of a single neutral atom to its three-dimensional vibrational ground state in an optical tweezer. After employing Raman sideband cooling for tens of milliseconds, we measure via sideband spectroscopy a three-dimensional ground-state occupation of ~90%. We further observe coherent control of the spin and motional state of the trapped atom. Our demonstration shows that an optical tweezer, formed simply by a tightly focused beam of light, creates sufficient confinement for efficient sideband cooling. This source of ground-state neutral atoms will be instrumental in numerous quantum simulation and logic applications that require a versatile platform for storing and manipulating ultracold single neutral atoms. For example, these results will improve current optical tweezer experiments studying atom-photon coupling and Rydberg quantum logic gates, and could provide new opportunities such as rapid production of single dipolar molecules or quantum simulation in tweezer arrays.Comment: Updated intro, titl

An Application of the Investment Model for Examining the Effects of Commitment, Self-Efficacy, and Goal Difficulty on Performance

This research was designed to test the presumed effects of commitment, self-efficacy, and goal difficulty level on task performance. The investment model of commitment was used to experimentally manipulate commitment levels. Eighty subjects served as their own controls. For a computer typing task, performance baseline was established, then subjects performed additional trials under various commitment-to-study, commitment-to-job, and goal difficulty conditions. Seven hypotheses were tested. Analyses were conducted to determine main effects of commitment-to-study, commitment-to-job, commitment-to-goals and interaction effects among experimental conditions. Performance score differences were significant for speed, but not accuracy across high and low commitment levels, supporting the hypothesis that commitment and performance are positively correlated. Organizational climate established in the commitment-to-study condition was shown to be a determinant of subsequent performance. Results supported Locke\u27s (1981) contention that commitment is necessary for goal-setting to work, but did not support the suggestion that difficult goals result in better performance. The hypothesis that task interest is related with satisfaction was confirmed, but hypotheses regarding relationships between task interest, facet satisfaction, and work motivation with performance were generally unsupported. Self-efficacy estimates of typing speed and accuracy made before feedback was received were significant predictors of performance, but estimates of accuracy consistently underestimated actual performance. Post-feedback efficacy estimates explained significantly more variance than pre-feedback estimates, as expected; however, accuracy estimates were resistant to revision based on feedback and did not show increased predictive power. Commitment levels did not have a differential impact on subjects\u27 post-feedback efficacy estimates. Results were interpreted in terms of task complexity, instrumentality, and arousal theory, and implications for future research and applications were discussed

How does a Latin American Music Initiative impact an American Charter School Community? Observations from El Sistema Boston [full paper]

Rooted in Venezuela, El Sistema is a visionary global movement that has transformed the lives of youth through music since 1975. A Boston public charter school restructured and invigorated its’ curriculum with the El Sistema music program in September 2010. The pedagogical focus of El Sistema is the orchestra, a model for an ideal community that advances the social and performance skills of students empowering their personal and musical development. Our project aimed to assess the impact of El Sistema, a Latin American education initiative, on an American urban charter school. Self-regulation, motivation, peer-respect and responsibility are the skills and behaviors that were of interest and markers for cognitive, emotional and social development beyond academic achievement. We observed and collected perceptions of social and behavioral changes in students and assessed the potential positive musical influence of El Sistema through a qualitative and quantitative music literacy test. In our observations, the El Sistema curriculum has been perceived as a positive influence on the students’ social and behavioral development. Participating in the program provides students with valuable social interactions, enabling them to engage in collaborative learning, as well as propelling their musical knowledge. Further assessment will determine the El Sistema curriculum’s impact outside of the music classroom. Through further observation of El Sistema programs throughout the U.S., we can observe and acknowledge the large scale impact of this Latin American music initiative in our country

A CubeSat for Calibrating Ground-Based and Sub-Orbital Millimeter-Wave Polarimeters (CalSat)

We describe a low-cost, open-access, CubeSat-based calibration instrument that is designed to support ground-based and sub-orbital experiments searching for various polarization signals in the cosmic microwave background (CMB). All modern CMB polarization experiments require a robust calibration program that will allow the effects of instrument-induced signals to be mitigated during data analysis. A bright, compact, and linearly polarized astrophysical source with polarization properties known to adequate precision does not exist. Therefore, we designed a space-based millimeter-wave calibration instrument, called CalSat, to serve as an open-access calibrator, and this paper describes the results of our design study. The calibration source on board CalSat is composed of five "tones" with one each at 47.1, 80.0, 140, 249 and 309 GHz. The five tones we chose are well matched to (i) the observation windows in the atmospheric transmittance spectra, (ii) the spectral bands commonly used in polarimeters by the CMB community, and (iii) The Amateur Satellite Service bands in the Table of Frequency Allocations used by the Federal Communications Commission. CalSat would be placed in a polar orbit allowing visibility from observatories in the Northern Hemisphere, such as Mauna Kea in Hawaii and Summit Station in Greenland, and the Southern Hemisphere, such as the Atacama Desert in Chile and the South Pole. CalSat also would be observable by balloon-borne instruments launched from a range of locations around the world. This global visibility makes CalSat the only source that can be observed by all terrestrial and sub-orbital observatories, thereby providing a universal standard that permits comparison between experiments using appreciably different measurement approaches

Long Lived Electronic Coherences in Molecular Wave Packets Probed with Pulse Shape Spectroscopy

We explore long lived electronic coherences in molecules using shaped ultrafast laser pulses to launch and probe entangled nuclear-electronic wave packets. We find that under certain conditions, the electronic phase remains well defined despite vibrational motion along many degrees of freedom. The experiments are interpreted with the help of electronic structure calculations which corroborate our interpretation of the measurement