9,751 research outputs found
The diffuse neutrino flux from supernovae: upper limit on the electron neutrino component from the non-observation of antineutrinos at SuperKamiokande
I derive an upper bound on the electron neutrino component of the diffuse
supernova neutrino flux from the constraint on the antineutrino component at
SuperKamiokande. The connection between antineutrino and neutrino channels is
due to the similarity of the muon and tau neutrino and antineutrino fluxes
produced in a supernova, and to the conversion of these species into electron
neutrinos and antineutrinos inside the star. The limit on the electron neutrino
flux is 5.5 cm^-2 s^-1 above 19.3 MeV of neutrino energy, and is stronger than
the direct limit from Mont Blanc by three orders of magnitude. It represents
the minimal sensitivity required at future direct searches, and is intriguingly
close to the reach of the Sudbury Neutrino Observatory (SNO) and of the ICARUS
experiment. The electron neutrino flux will have a lower bound if the electron
antineutrino flux is measured. Indicatively, the first can be smaller than the
second at most by a factor of 2-3 depending on the details of the neutrino
spectra at production.Comment: LaTeX, 5 pages, 1 figure. Paper is modified in the presentation (Fig.
1 was replaced with a different plot and Table 1 was expanded), with
unchanged results. References added and correcte
Recommended from our members
Learning-Related Values in Young Childrenâs Storybooks: An Investigation in the United States, China, and Mexico
This research examined the prevalence of learning-related values in childrenâs storybooks in the United States, China, and Mexico. Storybooks ( N = 157) were randomly selected from government-recommended booklists in each country. Trained coders assessed the prevalence of learning-related beliefs (e.g., malleability of ability), motivated cognitions (e.g., achievement orientation), and behaviors (e.g., effort) in the storybooks. A set of MANOVAs revealed that Chinese (vs. American and Mexican) storybooks contained more instances of learning-related beliefs and behaviors. For example, Chinese storybooks included more instances of achievement-related goals and behaviors, relative to storybooks in the United States and Mexico. With the exception of achievement goals and helplessness, the prevalence of learning-related qualities was largely similar in the United States and Mexico
Downscaling data assimilation algorithm with applications to statistical solutions of the Navier-Stokes equations
Based on a previously introduced downscaling data assimilation algorithm,
which employs a nudging term to synchronize the coarse mesh spatial scales, we
construct a determining map for recovering the full trajectories from their
corresponding coarse mesh spatial trajectories, and investigate its properties.
This map is then used to develop a downscaling data assimilation scheme for
statistical solutions of the two-dimensional Navier-Stokes equations, where the
coarse mesh spatial statistics of the system is obtained from discrete spatial
measurements. As a corollary, we deduce that statistical solutions for the
Navier-Stokes equations are determined by their coarse mesh spatial
distributions. Notably, we present our results in the context of the
Navier-Stokes equations; however, the tools are general enough to be
implemented for other dissipative evolution equations
Using visual analytics to develop situation awareness in astrophysics
We present a novel collaborative visual analytics application for cognitively overloaded users in the astrophysics domain. The system was developed for scientists who need to analyze heterogeneous, complex data under time pressure, and make predictions and time-critical decisions rapidly and correctly under a constant influx of changing data. The Sunfall Data Taking system utilizes several novel visualization and analysis techniques to enable a team of geographically distributed domain specialists to effectively and remotely maneuver a custom-built instrument under challenging operational conditions. Sunfall Data Taking has been in production use for 2 years by a major international astrophysics collaboration (the largest data volume supernova search currently in operation), and has substantially improved the operational efficiency of its users. We describe the system design process by an interdisciplinary team, the system architecture and the results of an informal usability evaluation of the production system by domain experts in the context of Endsley's three levels of situation awareness
- âŠ