The landforms of northern Gale crater on Mars expose thick sequences of sedimentary rocks. Based on images obtained by the Curiosity rover, we interpret these outcrops as evidence for past fluvial, ...deltaic, and lacustrine environments. Degradation of the crater wall and rim probably supplied these sediments, which advanced inward from the wall, infilling both the crater and an internal lake basin to a thickness of at least 75 meters. This intracrater lake system probably existed intermittently for thousands to millions of years, implying a relatively wet climate that supplied moisture to the crater rim and transported sediment via streams into the lake basin. The deposits in Gale crater were then exhumed, probably by wind-driven erosion, creating Aeolis Mons (Mount Sharp).
This paper describes the operation of the Coherent CAPTAIN-Mills (CCM) detector located at the Los Alamos Neutron Science Center at Los Alamos National Laboratory. CCM is a 10-ton liquid argon ...detector located 20 meters from a high flux neutron/neutrino source and is designed to search for sterile neutrinos (νs’s) and light dark matter (LDM). An engineering run was performed in fall 2019 to study the characteristics of the CCM120 detector by searching for coherent scattering signals consistent with νs’s and LDM resulting from the production and decays of π+ and π0 in the tungsten target. New parameter space in a leptophobic dark matter (DM) model was excluded for DM masses between ~2.0 and 30 MeV. The lessons learned from this run have guided the development and construction of the new CCM200 detector that will begin operations in 2021 and significantly improve on these searches.
A
bstract
This article reports global fits of short-baseline neutrino data to oscillation models involving light sterile neutrinos. In the commonly-used 3+1 plane wave model, there is a well-known ...4.9
σ
tension between data sets sensitive to appearance versus disappearance of neutrinos. We find that models that damp the oscillation prediction for the reactor data sets, especially at low energy, substantially improve the fits and reduce the tension. We consider two such scenarios. The first scenario introduces the quantum mechanical wavepacket effect that accounts for the source size in reactor experiments into the 3+1 model. We find that inclusion of the wavepacket effect greatly improves the overall fit compared to a three-neutrino model by ∆
χ
2
/
dof = 61
.
1
/
4 (7
.
1
σ
improvement) with best-fit ∆
m
2
= 1
.
4 eV
2
and wavepacket length of 67 fm. The internal tension is reduced to 3.4
σ
. If reactor-data only is fit, then the wavepacket preferred length is 91 fm (
>
20 fm at 99% CL). The second model introduces oscillations involving sterile flavor and allows the decay of the heaviest, mostly sterile mass state,
ν
4
. This model introduces a damping term similar to the wavepacket effect, but across all experiments. Compared to a three-neutrino fit, this has a ∆
χ
2
/
dof = 60
.
6
/
4 (7
σ
improvement) with preferred ∆
m
2
= 1
.
4 eV
2
and decay Γ = 0
.
35 eV. The internal tension is reduced to 3.7
σ
.
For many years, the reactor event rates have been observed to have structure that deviates from prediction. Community discussion has focused on an excess compared to prediction observed at 5 MeV; however, other deviations are apparent. This structure has
L
dependence that is well-fit by the damped models. Before assuming this points to new physics, we urge closer examination of systematic effects that could lead to this
L
dependence.
We study the phenomenology of neutrino decay together with neutrino oscillations in the context of eV-scale sterile neutrinos. We review the formalism of visible neutrino decay in which one of the ...decay products is a neutrino that potentially can be observed. We apply the formalism developed for decay to the recent sterile neutrino search performed by IceCube with TeV neutrinos. We show that for a ν4 lifetime τ4/m4≲10−16 eV−1 s, the interpretation of the high-energy IceCube analysis can be significantly changed.
The discovery of rare genetic variants is accelerating, and clear guidelines for distinguishing disease-causing sequence variants from the many potentially functional variants present in any human ...genome are urgently needed. Without rigorous standards we risk an acceleration of false-positive reports of causality, which would impede the translation of genomic research findings into the clinical diagnostic setting and hinder biological understanding of disease. Here we discuss the key challenges of assessing sequence variants in human disease, integrating both gene-level and variant-level support for causality. We propose guidelines for summarizing confidence in variant pathogenicity and highlight several areas that require further resource development.
The Community-Acquired Pneumonia Immunization Trial in Adults (CAPiTA) demonstrated the efficacy of 13-valent pneumococcal conjugate vaccine (PCV13) in preventing vaccine-type community-acquired ...pneumonia and vaccine-type invasive pneumococcal disease in elderly subjects. We examined the cost-effectiveness of PCV13 vaccination in the Netherlands. Using a Markov-type model, incremental cost-effectiveness ratios (ICER) of PCV13 vaccination in different age- and risk-groups for pneumococcal disease were evaluated using a societal perspective. Estimates of quality-adjusted life-years (QALYs), costs, vaccine efficacy and epidemiological data were based on the CAPiTA study and other prospective studies. The base-case was PCV13 vaccination of adults aged 65-74 years compared to no vaccination, assuming no net indirect effects in base-case due to paediatric 10-valent pneumococcal conjugate vaccine use. Analyses for age- and risk-group specific vaccination strategies and for different levels of hypothetical herd effects from a paediatric PCV programme were also conducted. The ICER for base-case was €8650 per QALY (95% CI 5750-17,100). Vaccination of high-risk individuals aged 65-74 years was cost-saving and extension to medium-risk individuals aged 65-74 years yielded an ICER of €2900. Further extension to include medium- and high-risk individuals aged ≥18 years yielded an ICER of €3100.PCV13 vaccination is highly cost-effective in the Netherlands. The transferability of our results to other countries depends upon vaccination strategies already implemented in those countries.
Neutrino oscillation models involving one extra mass eigenstate beyond the standard three (3+1) are fit to global short baseline experimental data and the recent IceCube ν_{μ}+νover ¯_{μ} ...disappearance search result. We find a best fit of Δm_{41}^{2}=1.75 eV^{2} with Δχ_{null-min}^{2}/d.o.f. of 50.61/4. We find that the combined IceCube and short baseline data constrain θ_{34} to <80°(<6°) at 90% C.L. for Δm_{41}^{2}≈2(6) eV^{2}, which is improved over present limits. Incorporating the IceCube information provides the first constraints on all entries of the 3+1 mixing matrix.
Recent global fits to short-baseline neutrino oscillation data have been performed finding preference for a sterile neutrino solution (3+1) over null. In the most recent iteration, it was pointed out ...that an unstable sterile neutrino (3+1+decay) may be a better description of the data. This is due to the fact that this model significantly reduces the tension between appearance and disappearance datasets. In this work, we add a 1-year IceCube dataset to the global fit obtaining new results for the standard 3+1 and 3+1+decay sterile neutrino scenarios. We find that the 3+1+decay model provides a better fit than the 3+1, even in the presence of IceCube, with reduced appearance to disappearance tension. The 3+1+decay model is a 5.4σ improvement over the null hypothesis and a 2.8σ improvement over the standard 3+1 model.
We perform a low-mass dark matter search using an exposure of 30 kg×yr with the XENON100 detector. By dropping the requirement of a scintillation signal and using only the ionization signal to ...determine the interaction energy, we lowered the energy threshold for detection to 0.7 keV for nuclear recoils. No dark matter detection can be claimed because a complete background model cannot be constructed without a primary scintillation signal. Instead, we compute an upper limit on the WIMP-nucleon scattering cross section under the assumption that every event passing our selection criteria could be a signal event. Using an energy interval from 0.7 keV to 9.1 keV, we derive a limit on the spin-independent WIMP-nucleon cross section that excludes WIMPs with a mass of 6 GeV/c2 above 1.4×10−41 cm2 at 90% confidence level.
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