3,096 research outputs found
Plasticity-Induced Magnetization in Amorphous Magnetic Solids
Amorphous magnetic solids, like metallic glasses, exhibit a novel effect: the
growth of magnetic order as a function of mechanical strain under athermal
conditions in the presence of a magnetic field. The magnetic moment increases
in steps whenever there is a plastic event. Thus plasticity induces the
magnetic ordering, acting as the effective noise driving the system towards
equilibrium. We present results of atomistic simulations of this effect in a
model of a magnetic amorphous solid subjected to pure shear and a magnetic
field. To elucidate the dependence on external strain and magnetic field we
offer a mean-field theory that provides an adequate qualitative understanding
of the observed phenomenon
Sensitivity to Z-prime and non-standard neutrino interactions from ultra-low threshold neutrino-nucleus coherent scattering
We discuss prospects for probing Z-prime and non-standard neutrino
interactions using neutrino-nucleus coherent scattering with ultra-low energy
(~ 10 eV) threshold Si and Ge detectors. The analysis is performed in the
context of a specific and contemporary reactor-based experimental proposal,
developed in cooperation with the Nuclear Science Center at Texas A&M
University, and referencing available technology based upon economical and
scalable detector arrays. For expected exposures, we show that sensitivity to
the Z-prime mass is on the order of several TeV, and is complementary to the
LHC search with low mass detectors in the near term. This technology is also
shown to provide sensitivity to the neutrino magnetic moment, at a level that
surpasses terrestrial limits, and is competitive with more stringent
astrophysical bounds. We demonstrate the benefits of combining silicon and
germanium detectors for distinguishing between classes of models of new
physics, and for suppressing correlated systematic uncertainties.Comment: As published in PRD; 13 pages, 7 figure
Non-standard interactions of solar neutrinos in dark matter experiments
Non-standard neutrino interactions (NSI) affect both their propagation
through matter and their detection, with bounds on NSI parameters coming from
various astrophysical and terrestrial neutrino experiments. In this paper, we
show that NSI can be probed in future direct dark matter detection experiments
through both elastic neutrino-electron scattering and coherent neutrino-nucleus
scattering, and that these channels provide complementary probes of NSI. We
show NSI can increase the event rate due to solar neutrinos, with a sharp
increase for lower nuclear recoil energy thresholds that are within reach for
upcoming detectors. We also identify an interference range of NSI parameters
for which the rate is reduced by approximately 40\%. Finally, we show that the
"dark side" solution for the solar neutrino mixing angle may be discovered at
forthcoming direct detection experiments.Comment: 12 pages, 5 figure
The Leptoquark Implication from the CMS and IceCube Experiments
The recent excess in the CMS measurements of and channels
and the emergence of PeV comsic neutrino events at the IceCube experiment share
an intriguing implication for a leptoquark with a 600-650 GeV mass. We
investigate the CMS constraints on the flavor structure of a scenario with the
minimal leptoquark Yukawa couplings and correlate such a scenario to the
resonant enhancement in the very high energy shower event rates at the IceCube.
We find for a single leptoquark, the CMS signals require large couplings to the
third generation leptons. This leads to an enhancement in the
-nucleon scattering cross-section and subsequently more
events at PeV energies. However, a visible enhancement above the Standard Model
scattering would require a leptoquark Yukawa coupling larger than one that can
be easily tested at the upcoming LHC runs.Comment: PRD version. Meson decay constraints and additional citations are
added. 6 pages, 2 figures, 1 tabl
Atomistic Simulations of Magnetic Amorphous Solids: Magnetostriction, Barkhausen noise and novel singularities
We present results of atomistic simulations of a new model of a magnetic
amorphous solid subjected to external mechanical strains and magnetic fields.
The model employed offers new perspectives on important effects like Barkhausen
noise and magnetostriction. It is shown that the plastic response in such
systems exhibit singularities characterized by unexpected exponents requiring
careful theoretical reasoning. The spatial structure of the plastic events
requires a new coarse grained elasto-magnetic theory which is provided here
No floors: Effective field theory treatment of the neutrino background in direct dark matter detection experiments
Distinguishing a dark matter interaction from an astrophysical
neutrino-induced interaction will be major challenge for future direct dark
matter searches. In this paper, we consider this issue within non-relativistic
Effective Field Theory (EFT), which provides a well-motivated theoretical
framework for determining nuclear responses to dark matter scattering events.
We analyze the nuclear energy recoil spectra from the different dark
matter-nucleon EFT operators, and compare to the nuclear recoil energy spectra
that is predicted to be induced by astrophysical neutrino sources. We determine
that for 11 of the 14 possible operators, the dark matter-induced recoil
spectra can be cleanly distinguished from the corresponding neutrino-induced
recoil spectra with moderate size detector technologies that are now being
pursued, e.g., these operators would require 0.5 tonne years to be
distinguished from the neutrino background for low mass dark matter. Our
results imply that in most models detectors with good energy resolution will be
able to distinguish a dark matter signal from a neutrino signal, without the
need for much larger detectors that must rely on additional information from
timing or direction
- …