Probing Exotic Physics With Supernova Neutrinos

Future galactic supernovae will provide an extremely long baseline for studying the properties and interactions of neutrinos. In this paper, we discuss the possibility of using such an event to constrain (or discover) the effects of exotic physics in scenarios that are not currently constrained and are not accessible with reactor or solar neutrino experiments. In particular, we focus on the cases of neutrino decay and quantum decoherence. We calculate the expected signal from a core-collapse supernova in both current and future water Cerenkov, scintillating, and liquid argon detectors, and find that such observations will be capable of distinguishing between many of these scenarios. Additionally, future detectors will be capable of making strong, model-independent conclusions by examining events associated with a galactic supernova's neutronization burst.Comment: 19 pages, 6 figure

What is the most beneficial diet for patients with diverticulosis?

A diet high in fiber (particularly fruit and vegetable fiber) and low in fat and red meat may help to decrease the risk of symptomatic diverticular disease (strength of recommendation [SOR]: C, case-control studies and a large prospective cohort study). For people with diverticular disease, a diet high in fiber might decrease the risk of complications (SOR: C, case series). No studies have evaluated the effect of nut and seed avoidance

Estimating magnetic fields of homes near transmission lines in the California Power Line Study.

The California Power Line Study is a case-control study investigating the relation between residences near transmission lines and risk of childhood leukemia. It includes 5788 childhood leukemia cases and 5788 matched primary controls born between 1986 and 2007. We describe the methodology for estimating magnetic fields at study residences as well as for characterizing sources of uncertainty in these estimates. Birth residences of study subjects were geocoded and their distances to transmission lines were ascertained. 302 residences were deemed sufficiently close to transmission lines to have non-zero magnetic fields attributable to the lines. These residences were visited and detailed data, describing the physical configuration and dimensions of the lines contributing to the magnetic field at the residence, were collected. Phasing, loading, and directional load flow data for years of birth and diagnosis for each subject as well as for the day of site visit were obtained from utilities when available; when yearly average load for a particular year was not available, extrapolated values based on expert knowledge and prediction models were obtained. These data were used to estimate the magnetic fields at the center, closest and farthest point of each residence. We found good correlation between calculated fields and spot measurements of fields taken on site during visits. Our modeling strategies yielded similar calculated field estimates, and they were in high agreement with utility extrapolations. Phasing was known for over 90% of the lines. Important sources of uncertainty included a lack of information on the precise location of residences located within apartment buildings or other complexes. Our findings suggest that we were able to achieve high specificity in exposure assessment, which is essential for examining the association between distance to or magnetic fields from power lines and childhood leukemia risk

The ultraviolet spectra of radio-loud and radio-quiet quasars

The rest-frame ultraviolet spectral properties of matched samples of radio-loud, radio-moderate, and radio-quiet quasars are investigated, using quasars drawn from the Large Bright QSO Survey. We confirm the absence of spectral differences between radio-loud and radio-quiet quasars at rest-frame wavelengths longward of 1600 Á, as reported by previous authors. However, at shorter wavelengths we find a significant difference: radio-loud quasars have narrower (96% confidence), higher equivalent-width (97% confidence) Lyman-a and C IV emission lines. We further investigate quasars which are radio quiet, but have radio-to-optical flux ratios at the upper extreme of the radio-quiet population. Broad absorption line quasars are overabundant by a factor of —10 in this radio-moderate population; the overabundance is significant at a 99.99% confidence level.The LBQS is supported by National Science Foundation Grant No. AST 90-01181, for which we are grateful. Peter Strittmatter kindly made funds available for publication. We also wish to thank Craig Foltz and Paul Hewett for many helpful discussions. P.J.F. is supported by a SERC/ NATO advanced fellowship

Implications of CoGeNT's New Results For Dark Matter

The CoGeNT collaboration has recently presented the results of their first 15 months of data, including the measurement of the spectrum of nuclear recoil candidate events, and the time variation of those events. These results appear consistent with the signal anticipated from a relatively light dark matter particle scattering elastically with nuclei. In this paper, we independently analyze the data set collected by CoGeNT and explore the implications of these results for dark matter. We find that the observed spectrum and rate is consistent with originating from dark matter particles with a mass in the range of 4.5-12 GeV and an elastic scattering cross section with nucleons of approximately ~10^-40 cm^2. We confirm the conclusion of the CoGeNT collaboration that the data also includes a somewhat statistically significant (2.7 sigma) indication of annual modulation, with a phase, period, and amplitude consistent with that predicted for dark matter. CoGeNT's phase is also consistent with the annual modulation reported by the DAMA/LIBRA collaboration. We also discuss the null results reported by CDMS and XENON100, and comment on the prospects for other experiments to detect a dark matter particle with the properties implied by CoGeNT.Comment: 10 pages, 8 figure