260 research outputs found
Searching for physics beyond the Standard Model through the dipole interaction
The magnetic dipole interaction played a central role in the development of
QED, and continued in that role for the Standard Model. The muon anomalous
magnetic moment has served as a benchmark for models of new physics, and the
present experimental value is larger than the standard-model value by more than
three standard deviations. The electric dipole moment (EDM) violates parity
({}) and time-reversal ({}) symmetries, and in the context of the
theorem, the combination of charge conjugation and parity (). Since a new
source of {} violation outside of that observed in the and meson
systems is needed to help explain the baryon asymmetry of the universe,
searches for EDMs are being carried out worldwide on a number of systems. The
standard-model value of the EDM is immeasurably small, so any evidence for an
EDM would signify the observation of new physics. Unique opportunities exist
for EDM searches using polarized proton, deuteron or muon beams in storage
rings. This talk will provide an overview of the theory of dipole moments, and
the relevant experiments. The connection to the transition dipole moment that
could produce lepton flavor violating interactions such as is also mentioned.Comment: Invited Plenary talk at the 19th International Spin Physics
Symposium, Juelic
OGLE-2005-BLG-018: Characterization of Full Physical and Orbital Parameters of a Gravitational Binary Lens
We present the analysis result of a gravitational binary-lensing event
OGLE-2005-BLG-018. The light curve of the event is characterized by 2 adjacent
strong features and a single weak feature separated from the strong features.
The light curve exhibits noticeable deviations from the best-fit model based on
standard binary parameters. To explain the deviation, we test models including
various higher-order effects of the motions of the observer, source, and lens.
From this, we find that it is necessary to account for the orbital motion of
the lens in describing the light curve. From modeling of the light curve
considering the parallax effect and Keplerian orbital motion, we are able to
measure not only the physical parameters but also a complete orbital solution
of the lens system. It is found that the event was produced by a binary lens
located in the Galactic bulge with a distance kpc from the Earth.
The individual lens components with masses and are separated with a semi-major axis of AU and
orbiting each other with a period yr. The event demonstrates
that it is possible to extract detailed information about binary lens systems
from well-resolved lensing light curves.Comment: 19 pages, 6 figure
The Art of Suicide - The Pain in Paintings
This research projects deals with the question of whether the paintings of artists who have committed suicide is reflective of their mental states both in terms of content and form. It specifically attempts to answer whether the deterioration in mental state from a time of better mental health to the time of their suicide is expressed graphically in the paintings of those artists and whether this can be reliably observed. It was discovered that paintings in the absence of contact with or interpretation by the artists, provided enough information to enable non-expert judges to make reliable global content-related judgements (e.g. destructiveness and hopelessness) as well as form-specific ratings (e.g. lack of detail) that distinguished between paintings created near the time of artistsâ suicides and their paintings created at a time of better mental health as well as paintings from artists who were suffering from depression. It was also found that non-expert judges were able to correctly identify paintings that were created just before artistsâ suicides as reflecting serious mental health problems. Furthermore, it was discovered that there was a general preference for paintings from depressed artists over the last paintings by artists who have taken their own lives. The implications of these findings for clinical work both in terms of assessment and treatment were discussed. Furthermore, several limitations of this research project were noted and suggestions for future research were provided
Flared Disks and Silicate Emission in Young Brown Dwarfs
We present mid-infrared photometry of three very young brown dwarfs located
in the Ophiuchi star-forming region -- GY5, GY11 and GY310 --obtained
with the Subaru 8-meter telescope. All three sources were detected at 8.6 and
11.7m, confirming the presence of significant mid-infrared excess arising
from optically thick dusty disks. The spectral energy distributions of both
GY310 and GY11 exhibit strong evidence of flared disks; flat disks can be ruled
out for these two brown dwarfs. The data for GY5 show large scatter, and are
marginally consistent with both flared and flat configurations. Inner holes a
few substellar radii in size are indicated in all three cases (and especially
in GY11), in agreement with magnetospheric accretion models. Finally, our
9.7m flux for GY310 implies silicate emission from small grains on the
disk surface (though the data do not completely preclude larger grains with no
silicate feature). Our results demonstrate that disks around young substellar
objects are analogous to those girdling classical T Tauri stars, and exhibit a
similar range of disk geometries and dust properties.Comment: submitted to Astrophysical Journal Letter
The Mid-Infrared Emitting Dust Around AB Aur
Using the Keck I telescope, we have obtained 11.7 micron and 18.7 micron
images of the circumstellar dust emission from AB Aur, a Herbig Ae star. We
find that AB Aur is probably resolved at 18.7 micron with an angular diameter
of 1.2" at a surface brightness of 3.5 Jy/arcsec^2. Most of the dust mass
detected at millimeter wavelengths does not contribute to the 18.7 micron
emission, which is plausibly explained if the system possesses a relatively
cold, massive disk. We find that models with an optically thick, geometrically
thin disk, surrounded by an optically thin spherical envelope fit the data
somewhat better than flared disk models.Comment: ApJ in press, 4 color figure
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When was medieval philosophy?
Typescript of an Inaugural Lecture by John Marenbon, as Honorary Professor of Medieval Philosophy in the University of Cambridge, delivered November 30, 2011.John Marenbon argues against the usual chronological division, according to which there was a period of âmedieval philosophyâ corresponding roughly to the Middle Ages. Using as his basis an argument about why studying antiquated philosophy is valuable, he explains why such a question about chronological divisions is important
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