The ADMX collaboration gathered data for its Run 1A axion dark matter search from January to June 2017, scanning with an axion haloscope over the frequency range 645-680 MHz (2.66-2.81 μeV in axion ...mass) at DFSZ sensitivity. The resulting axion search found no axion-like signals comprising all the dark matter in the form of a virialized galactic halo over the entire frequency range, implying lower bound exclusion limits at or below DFSZ coupling at the 90% confidence level. This paper presents expanded details of the axion search analysis of Run 1A, including review of relevant experimental systems, data-taking operations, preparation and interpretation of raw data, axion search methodology, candidate handling, and final axion limits.
Dedicated spectrometers for terahertz radiation with 0.3,30 THz frequencies using traditional optomechanical interferometryare substantially less common than their infrared and microwavecounterparts. ...This paper presents public documentation for thedesign and initial performance measurements of a tabletop Fouriertransform spectrometer (FTS) for terahertz spectral analysis usinginfrared optics in a Michelson arrangement. This is coupled to abroadband pyroelectric photodetector designed for 0.1, 30 THzfrequencies. We measure spectra of narrowband and broadband inputradiation to characterize the performance of this instrument above10 THz, where signal-to-noise is high. This device is constructedin the context of research-and-development for the recently-proposedBroadband Reflector Experiment for Axion Detection (BREAD), wherethe optical components can be applied to ongoing efforts for testingthe pilot experiment.
Suppressor of
IKK
epsilon (
SIKE
) is associated with the type I interferon response of the innate immune system through
TANK
‐binding kinase 1 (
TBK
1). Originally characterized as an endogenous ...inhibitor of
TBK
1 when overexpressed in viral infection and pathological cardiac hypertrophic models, a mechanistic study revealed that
SIKE
acts as a high‐affinity substrate of
TBK
1, but its function remains unknown. In this work, we report that scratch assay analysis of parental and
SIKE CRISPR
/Cas9 knockout
HAP
1 cells showed an ~ 20% decrease in cell migration. Investigation of the
SIKE
interaction network through affinity purification/mass spectrometry showed that
SIKE
formed interactions with cytoskeletal proteins. In immunofluorescence assays, endogenous
SIKE
localized to cytosolic puncta in both epithelial and myeloid cells and to nuclear puncta in myeloid cells, while in epithelial cells additional staining occurred in stress fiber‐like structures and adjacent to the plasma membrane. Using cellular markers, co‐occurrence of
SIKE
fluorescence with actin, α‐actinin, and ezrin was detected. Reciprocal immunoprecipitation revealed a
SIKE
:tubulin interaction sensitive to the phosphorylation state of
SIKE
, but a
SIKE
:α‐actinin interaction was unchanged by
SIKE
phosphorylation.
In vitro
precipitation assays confirmed a direct
SIKE
interaction with tubulin and α‐actinin. These results indicate that
SIKE
may promote cell migration by directly associating with the cytoskeleton. In this role,
SIKE
may mediate cytoskeletal rearrangement necessary in innate immunity, but also link a key catalytic hub,
TBK
1, to the cytoskeleton.
Database
The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the
PRIDE
1 partner repository with the dataset identifier
PXD
007262.
We report the direct measurement of the {sup 7}Be solar neutrino signal rate performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso. The interaction rate of the 0.862 MeV ...{sup 7}Be neutrinos is 49{+-}3{sub stat}{+-}4{sub syst} counts/(day{center_dot}100 ton). The hypothesis of no oscillation for {sup 7}Be solar neutrinos is inconsistent with our measurement at the 4{sigma} C.L. Our result is the first direct measurement of the survival probability for solar {nu}{sub e} in the transition region between matter-enhanced and vacuum-driven oscillations. The measurement improves the experimental determination of the flux of {sup 7}Be, pp, and CNO solar {nu}{sub e}, and the limit on the effective neutrino magnetic moment using solar neutrinos.
The Axion Dark Matter eXperiment (ADMX) has previously excluded Dine-Fischler-Srednicki- Zhitnisky (DFSZ) axions between 680-790 MHz under the assumption that the dark matter is described by the ...isothermal halo model. However, the precise nature of the velocity distribution of dark matter is still unknown, and alternative models have been proposed. Here, we report the results of a non-virialized axion search over the mass range 2.81–3.31 µeV, corresponding to the frequency range 680–800 MHz. This analysis marks the most sensitive search for non-virialized axions sensitive to Doppler effects in the Milky Way Halo to date. Accounting for frequency shifts due to the detector’s motion through the Galaxy, we exclude cold flow relic axions with a velocity dispersion of $\mathscr{O}$(10-7)c with 95% confidence.
The bubble nucleation efficiency of low-energy nuclear recoils in superheated liquids plays a crucial role in interpreting results from direct searches for weakly interacting massive particle (WIMP) ...dark matter. Here, the PICO collaboration presents the results of the efficiencies for bubble nucleation from carbon and fluorine recoils in superheated C3F8 from calibration data taken with five distinct neutron spectra at various thermodynamic thresholds ranging from 2.1 to 3.9 keV. Instead of assuming any particular functional forms for the nuclear recoil efficiency, a generalized piecewise linear model is proposed with systematic errors included as nuisance parameters to minimize model-introduced uncertainties. A Markov chain Monte Carlo routine is applied to sample the nuclear recoil efficiency for fluorine and carbon at 2.45 and 3.29 keV thermodynamic thresholds simultaneously. The nucleation efficiency for fluorine was found to be ≥ 50% for nuclear recoils of 3.3 keV (3.7 keV) at a thermodynamic Seitz threshold of 2.45 keV (3.29 keV), and for carbon the efficiency was found to be ≥ 50% for recoils of 10.6 keV (11.1 keV) at a threshold of 2.45 keV (3.29 keV). Simulated datasets are used to calculate a p value for the fit, confirming that the model used is compatible with the data. The fit paradigm is also assessed for potential systematic biases, which although small, are corrected for. Additional steps are performed to calculate the expected interaction rates of WIMPs in the PICO-60 detector, a requirement for calculating WIMP exclusion limits.
Many compelling models predict dark matter coupling to the electromagnetic current through higher multipole interactions, while remaining electrically neutral. Different multipole couplings have been ...studied, among them anapole moment, electric and magnetic dipole moments, and millicharge. This study sets limits on the couplings for these photon-mediated interactions using nonrelativistic contact operators in an effective field theory framework. Using data from the PICO-60 bubble chamber leading limits for dark matter masses between 2.7 and 24 GeV/c2 and above 265 GeV/c2 (anapole moment), 2.7 and 11.7 GeV/c2 (electric moment), 3 and 9.5 GeV/c2 (magnetic moment), and 2.7 and 12 GeV/c2 (millicharged) are reported for the coupling of these photon-mediated dark matter-nucleus interactions. The detector was filled with 52 kg of C3F8 operating at thermodynamic thresholds of 2.45 keV and 3.29 keV, reaching exposures of 1404 kg-day and 1167 kg-day, respectively.
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