33 research outputs found
FCNC PROCESSES IN THE LITTLEST HIGGS MODEL WITH T-PARITY: AN UPDATE
No full textWe update our 2006-2007 results for FCNC processes in the Littlest Higgs model with T-parity (LHT). The removal of the logarithmic UV cutoff dependence in our previous results through a new contribution to the Z(0)-penguin diagrams identified by Goto et al. and del Aguila et al., while making the deviations from the SM expectations in the quark sector less spectacular, still allows for sizable new physics effects in K -> pi nu(nu) over bar and K(L) -> pi(0)l(+)l(-) decays and in the CP-asymmetry S(psi phi) with the latter unaffected by the new contribution. We extend our analysis by a study of the fine-tuning required to fit the data on epsilon(K) and by the inclusion of the decay K(L) -> mu(+)mu(-). A number of correlations can distinguish this model from the custodially protected Randall-Sundrum model analysed recently. We also reconsider lepton flavour violating decays, including now a discussion of fine-tuning. While the l(i) -> l(j)gamma decays are unaffected by the removal of the logarithmic cutoff dependence, the branching ratios for decays with three leptons in the final state, like mu -> 3e are lowered by almost an order of magnitude. In spite of this, the pattern of lepton flavour violation in the LHT model can still be distinguished from the one in supersymmetric models
Matthew as marginal scribe in an advanced agrarian society
No full textAnalysis of 22 references to scribes in the Gospel of Matthew shows that a few of them are positive comments and that the author himself was a scribe. What type of scribe was he and how can we clarify his social context? By means of the models of Lenski and Kautsky, by recent research about scribes, literacy, and
power, and by new marginality theory, this article extensively refines Saldarini’s hypothesis that the scribes were “retainers”. The thesis is that in “Matthew’s” Christ-believing group, his scribal profession and literacy meant power and socio-
religious status. Yet, his voluntary association with Christ believers (“ideological marginality”), many of whom could not participate in social roles expected of them (“structural marginality”), led to his living between two historical traditions, languages, political loyalties, moral codes, social rankings, and ideological-
religious sympathies (“cultural marginality”). The Matthean author’s cultural marginality will help to clarify certain well-known literary tensions in the Gospel of Matthew
Ganymede MHD Model: Magnetospheric Context for Juno's PJ34 Flyby
No full textOn June 7th, 2021 the Juno spacecraft visited Ganymede and provided the first
in situ observations since Galileo's last flyby in 2000. The measurements
obtained along a one-dimensional trajectory can be brought into global context
with the help of three-dimensional magnetospheric models. Here we apply the
magnetohydrodynamic model of Duling et al. (2014) to conditions during the Juno
flyby. In addition to the global distribution of plasma variables we provide
mapping of Juno's position along magnetic field lines, Juno's distance from
closed field lines and detailed information about the magnetic field's
topology. We find that Juno did not enter the closed field line region and that
the boundary between open and closed field lines on the surface matches the
poleward edges of the observed auroral ovals. To estimate the sensitivity of
the model results, we carry out a parameter study with different upstream
plasma conditions and other model parameters
Matthew and marginality
No full textThis article explores marginality theory as it was first proposed in the social sciences, that is related to persons caught between two competing cultures (Park; Stonequist), and, then, as it was developed in sociology as related to the poor (Germani) and in anthropology as it was related to involuntary marginality and voluntary marginality (Victor Turner). It then examines a (normative scheme' in antiquity that creates involuntary marginality at the macrosocial level, namely, Lenski's social stratification model in an agrarian society, and indicates how Matthean language might fit with a sample inventory of socioreligious roles. Next, it examines some (normative schemes' in antiquity for voluntary margi-nality at the microsocial level, namely, groups, and examines how the Matthean gospel would fit based on indications of factions and leaders. The article ,shows that the author of the Gospel of Matthew has an ideology of (voluntary marginality', but his gospel includes some hope for (involuntary marginals' in the real world, though it is somewhat tempered. It also suggests that the writer of the Gospel is a (marginal man', especially in the sense defined by the early theorists (Park; Stone-quist)
Tissue oximetry by diffusive reflective visible light spectroscopy: Comparison of algorithms and their robustness
No full textIt is essential to measure tissue oxygen saturation (StO2) locally and in thin layers of tissue, for example, the bronchial mucosa, skin flaps and small bones. Visible light spectroscopy (VLS) with a shallow penetration depth is suitable method. Although several VLS algorithms have been developed and described, they have not yet been compared to each other. This hinders attempts to compare the clinical results obtained by different algorithms. To address this issue, we compared the algorithms of Harrison, Knoefel, Pittman‐Duling, Sato and our OxyVLS oximeter, which applies the algorithm from Wodick and Lübbers, in a liquid phantom with optical properties of human tissue. We generally observed considerable differences between the algorithms, which were StO2 dependent. Exceptions were OxyVLS and Sato, showing a high level of agreement with negligible StO2 dependency. In spite of the considerable deviation between the other algorithms, the difference of StO2 between them in clinically normal StO2 was <10%. We did not observe any dependency of the algorithms on hemoglobin content of the phantom or temperature
The search for a subsurface ocean in Ganymede with Hubble Space Telescope observations of its auroral ovals
No full textWe present a new approach to search for a subsurface ocean within Ganymede through observations and modeling of the dynamics of its auroral ovals. The locations of the auroral ovals oscillate due to Jupiter's time‐varying magnetospheric field seen in the rest frame of Ganymede. If an electrically conductive ocean is present, the external time‐varying magnetic field is reduced due to induction within the ocean and the oscillation amplitude of the ovals decreases. Hubble Space Telescope (HST) observations show that the locations of the ovals oscillate on average by 2.0° ±1.3°. Our model calculations predict a significantly stronger oscillation by 5.8° ± 1.3° without ocean compared to 2.2°±1.3° if an ocean is present. Because the ocean and the no‐ocean hypotheses cannot be separated by simple visual inspection of individual HST images, we apply a statistical analysis including a Monte Carlo test to also address the uncertainty caused by the patchiness of observed emissions. The observations require a minimum electrical conductivity of 0.09 S/m for an ocean assumed to be located between 150 km and 250 km depth or alternatively a maximum depth of the top of the ocean at 330 km. Our analysis implies that Ganymede's dynamo possesses an outstandingly low quadrupole‐to‐dipole moment ratio. The new technique applied here is suited to probe the interior of other planetary bodies by monitoring their auroral response to time‐varying magnetic fields.Key PointsNew technique to search for a subsurface ocean in Ganymede with a telescopeOcean affects auroral oscillation caused by time‐varying external magnetic fieldHST observations reveal weak auroral oscillation and imply existence of oceanPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111157/1/jgra51618.pd
Analysis of the gain-coupled DFL as a source of short optical pulses
No full textThesis (Ph. D.)--University of Rochester. College of Engineering and Applied Science. Institute of Optics, 1985. This thesis was digitized by the Institute of Optics in 2014 and was determined to have lapsed into the public domain. If you are the author and have questions about the digitization of your work, please contact Kari Brick, Graduate Program Coordinator for the Institute of Optics, at [email protected]. Other contact information for the Institute is available at http://www.optics.rochester.eduThe results of an investigation of the distributed feedback laser (DFL) as a source for short optical pulses is reported in this thesis. The DFL provides a uniquely simple and inexpensive alternative to synchronously pumped dye lasers. The fundamental difference is the use of a modulation of the refractive index of the gain medium to provide feedback instead of external cavity mirrors. This feedback method allows the laser to produce short pulses from a single pump pulse. The modulation also limits the bandwidth of the oscillation so that the pulses are constrained to be transform limited.
To determine the optimal conditions for the production of short pulses a semiclassical rate equation model of the DFL was developed. This model is capable of predicting the output characteristics of the laser under any pumping conditions from steady state to short pulse pumping. The results from this model are shown to agree well with the existing theories in the limits where they are valid. The output duration of the laser pulse is shown to rely primarily on the cavity length and the pump pulse duration. A curve which combines these two dependences is presented which is capable of predicting the performance of any given DFL.
To compliment the theoretical study, an experimental examination of the DFL was conducted. The output was observed on a picosecond synchronized streak camera. In addition a probe pulse was scattered from the transient feedback of the laser providing a direct measurement of the modulation present. In the course of this investigation a number of Nd:YAG laser systems were constructed and evaluated as pump sources for the DFL. One such system, the cw-pumped regenerative amplifier represents a significant technological advance over previous systems for providing high power, high repetition rate, stable pulses at 1.06 um. The use of these systems as the pump for synchronous dye amplifier systems is also presented
Analysis of Enceladus’s Time-variable Space Environment to Magnetically Sound its Interior
No full textWe provide a comprehensive study of Enceladus’s time-variable magnetic field environment and identify in measurements of the Cassini spacecraft signatures that appear to be consistent with induced fields from the moon’s interior. Therefore, we first analyze the background field Enceladus is exposed to within 21 flybys and 50 crossings of the moon’s orbit by the Cassini spacecraft. Considering magnetic field variability due to Enceladus’s eccentric orbit, Saturn’s planetary period oscillations, and local time effects within the magnetospheric current sheet, we construct predictive, time-variable background fields near Enceladus with a correlation coefficient of 0.75 and larger compared to the measured background fields. Subsequently, we build a geophysically based electrical conductivity model of Enceladus’s ocean from the equation of state for saline water and mixing laws for a porous core permeated by water. Using this conductivity model and the derived time-variable fields, we calculate expected induced fields. For close flybys, we identify within mostly plume-dominated magnetic field perturbations of 10–30 nT much smaller perturbations of 1–3 nT, which could be consistent with induction. The flybys over Enceladus’s north pole are best suited for induction studies, and the associated measurements suggest that a conductivity of the ocean with 1–3 S m ^–1 is not sufficient to produce an adequate induction response, but they support a highly conductive, porous core of 20–30 S m ^–1 and/or a more conductive ocean. Our study also provides strategies for future magnetic sounding of Enceladus
Ganymede MHD Model: Magnetospheric Context for Juno's PJ34 Flyby
No full textAbstractOn 7 June 2021 the Juno spacecraft visited Ganymede and provided the first in situ observations since Galileo's last flyby in 2000. The measurements obtained along a one‐dimensional trajectory can be brought into global context with the help of three‐dimensional magnetospheric models. Here we apply the magnetohydrodynamic model of Duling et al. (2014, https://doi.org/10.1002/2013ja019554) to conditions during the Juno flyby. In addition to the global distribution of plasma variables we provide mapping of Juno's position along magnetic field lines, Juno's distance from closed field lines and detailed information about the magnetic field's topology. We find that Juno did not enter the closed field line region and that the boundary between open and closed field lines on the surface matches the poleward edges of the observed auroral ovals. To estimate the sensitivity of the model results, we carry out a parameter study with different upstream plasma conditions and other model parameters.Plain Language Summary: In June 2021 the Juno spacecraft flew close to Ganymede, the largest moon of Jupiter, and explored its magnetic and plasma environment. Ganymede's own magnetic field forms a magnetosphere, which is embedded in Jupiter's large‐scale magnetosphere, and which is unique in the solar system. The vicinity of Ganymede is separated into regions that differ in whether the magnetic field lines connect to Ganymede's surface at both or one end or not at all. These regions are deformed by the plasma flow and determine the state of the plasma and the location of Ganymede's aurora. We perform simulations of the plasma flow and interaction to reveal the three‐dimensional structure of Ganymede's magnetosphere during the flyby of Juno. The model provides the three‐dimensional state of the plasma and magnetic field, predicted locations of the aurora and the geometrical magnetic context for Juno's trajectory. These results are helpful for the interpretation of the in situ and remote sensing obtained during the flyby. We find that Juno did not cross the region with field lines that connect to Ganymede's surface at both ends. Considering possible values for unknown model parameters, we also estimate the uncertainty of the model results.Key Points:
Our magnetohydrodynamic model illustrates the state of Ganymede's magnetosphere during Juno's flyby and locates its trajectory outside closed field lines
The location of the open‐closed‐field line‐boundary is predicted and matches the poleward edges of the aurora as observed by Juno
We investigate model uncertainties caused by incomplete knowledge of upstream conditions and other parameters
H2020 European Research Council
http://dx.doi.org/10.13039/100010663University of Iowa
http://dx.doi.org/10.13039/100008893National Aeronautics and Space Administration
http://dx.doi.org/10.13039/100000104Southwest Research Institute
http://dx.doi.org/10.13039/100011766http://www.netpurgatory.com/zeusmp.htmlhttps://doi.org/10.17189/1519711https://doi.org/10.5281/zenodo.7096938https://doi.org/10.5281/zenodo.710533
Pulse dropout in harmonically mode-locked fiber lasers
No full textWe have studied theoretically and experimentally supermode competition in an actively mode-locked Er-fiber laser that operates in a high harmonic mode. Using an innovative numerical technique that allows us to properly account for the complex interaction of multiple pulses with the gain media, we could study the dynamics that leads to supermode competition, pulse dropouts, and pulse pair generation, and to accurately predict the limits of the stable operating regime.This work was supported by the U.S. Department of Energy, the National Science Foundation, and by the Wolfson Foundation.https://ieeexplore.ieee.org/document/826909/author
