942 research outputs found
Spring Comes With The Years
Last period in Mrs. Lubell\u27s sixth-grade social studies class was always hard to sit through, especially on the warm spring days when subtle lilac fragrances and sparrow soliloquies were lifted through the flung-open windows of the second-floor classroom..
Neutrino-nucleus coherent scattering as a probe of neutron density distributions
Neutrino-nucleus coherent elastic scattering provides a theoretically
appealing way to measure the neutron part of nuclear form factors. Using an
expansion of form factors into moments, we show that neutrinos from stopped
pions can probe not only the second moment of the form factor (the neutron
radius) but also the fourth moment. Using simple Monte Carlo techniques for
argon, germanium, and xenon detectors of 3.5 tonnes, 1.5 tonnes, and 300 kg,
respectively, we show that the neutron radii can be found with an uncertainty
of a few percent when near a neutrino flux of
neutrinos/cm/s. If the normalization of the neutrino flux is known
independently, one can determine the moments accurately enough to discriminate
among the predictions of various nuclear energy functionals.Comment: 10 pages, 5 figure
The Hunt for No Neutrinos
Four experiments have demonstrated new levels of sensitivity to neutrinoless double-beta decay, a process whose existence would prove that neutrinos are their own antiparticles
Adaptation and the Courtroom: Judging Climate Science
Climate science is increasingly showing up in courtroom disputes over the duty to adapt to climate change. While judges play a critical role in evaluating scientific evidence, they are not apt to be familiar with the basic methods of climate science nor with the role played by peer review, publication, and training of climate scientists. This Article is an attempt to educate the bench and the bar on the basics of the discipline of climate science, which we contend is a distinct scientific discipline. We propose a series of principles to guide a judge’s evaluation of the reliability and weight to be accorded a given climate scientists’ claim or opinion. The principles are designed to aid a judge in evaluating whether the expert’s testimony complies with the Daubert test for the admissibility of scientific evidence but are broadly applicable to a judge’s evaluation of agency science-based decisions
Adaptation and the Courtroom: Judging Climate Science
Climate science is increasingly showing up in courtroom disputes over the duty to adapt to climate change. While judges play a critical role in evaluating scientific evidence, they are not apt to be familiar with the basic methods of climate science nor with the role played by peer review, publication, and training of climate scientists. This Article is an attempt to educate the bench and the bar on the basics of the discipline of climate science, which we contend is a distinct scientific discipline. We propose a series of principles to guide a judge’s evaluation of the reliability and weight to be accorded a given climate scientists’ claim or opinion. The principles are designed to aid a judge in evaluating whether the expert’s testimony complies with the Daubert test for the admissibility of scientific evidence but are broadly applicable to a judge’s evaluation of agency science-based decisions
Anatomy of nuclear matrix elements for neutrinoless double-beta decay
We show that, within the Quasiparticle Random Phase Approximation (QRPA) and
the renormalized QRPA (RQRPA) based on the Bonn CD nucleon-nucleon interaction,
the competition between the pairing and the neutron-proton particle-particle
and particle-hole interactions causes contributions to the neutrinoless
double-beta decay matrix element to nearly vanish at internucleon distances of
more than 2 or 3 fermis. As a result, the matrix element is more sensitive to
short-range/high-momentum physics than one naively expects. We analyze various
ways of treating that physics and quantify the uncertainty it produces in the
matrix elements, with three different treatments of short-range correlations.Comment: Version to appear in Phys. Rev.
Effective double-beta-decay operator for 76Ge and 82Se
We use diagrammatic many-body perturbation theory in combination with
low-momentum interactions derived from chiral effective field theory to
construct effective shell-model transition operators for the neutrinoless
double-beta decay of 76Ge and 82Se. We include all unfolded diagrams to first-
and second-order in the interaction and all singly folded diagrams that can be
constructed from them. The resulting effective operator, which accounts for
physics outside the shell-model space, increases the nuclear matrix element by
about 20% in 76Ge and 30% in 82Se.Comment: 8 pages, 5 figure
Microfabricated pressure and shear stress sensors
A microfabricated pressure sensor. The pressure sensor comprises a raised diaphragm disposed on a substrate. The diaphragm is configured to bend in response to an applied pressure difference. A strain gauge of a conductive material is coupled to a surface of the raised diaphragm and to at least one of the substrate and a piece rigidly connected to the substrate
Fully self-consistent calculations of nuclear Schiff moments
We calculate the Schiff moments of the nuclei 199Hg and 211Ra in completely
self-consistent odd-nucleus mean-field theory by modifying the
Hartree-Fock-Bogoliubov code HFODD. We allow for arbitrary shape deformation,
and include the effects of nucleon dipole moments alongside those of a
CP-violating pion-exchange nucleon-nucleon interaction. The results for 199Hg
differ significantly from those of previous calculations when the CP-violating
interaction is of isovector character.Comment: 7 pages, 2 figure
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