4,277 research outputs found
The Up-Shot of Inelastic Down-Scattering at CDMS-Si
We study dark matter that inelastically scatters and de-excites in direct
detection experiments, as an interpretation of the CDMS-Si events in light of
the recent LUX data. The constraints from LUX and XENON10 require the
mass-splitting between the DM excited and de-excited states to be keV. At the same time, the CDMS-Si data itself do not allow for a
consistent DM interpretation for mass splittings larger than 200 keV. We find that a low threshold analysis will be needed to rule out this
interpretation of the CDMS-Si events. In a simple model with a kinetically
mixed dark photon, we show that the CDMS-Si rate and the thermal relic
abundance can both be accommodated.Comment: 10 pages, 3 figures; updated to match PRD versio
Halo Independent Direct Detection of Momentum-Dependent Dark Matter
We show that the momentum dependence of dark matter interactions with nuclei
can be probed in direct detection experiments without knowledge of the dark
matter velocity distribution. This is one of the few properties of DM
microphysics that can be determined with direct detection alone, given a signal
of dark matter in multiple direct detection experiments with different targets.
Long-range interactions arising from the exchange of a light mediator are one
example of momentum-dependent DM. For data produced from the exchange of a
massless mediator we find for example that the mediator mass can be constrained
to be MeV for DM in the 20-1000 GeV range in a halo-independent
manner.Comment: 15 pages, 4 figures; updated to match published versio
New or Missing Energy? Discriminating Dark Matter from Neutrino Interactions at the LHC
Missing energy signals such as monojets are a possible signature of Dark
Matter (DM) at colliders. However, neutrino interactions beyond the Standard
Model may also produce missing energy signals. In order to conclude that new
"missing particles" are observed the hypothesis of BSM neutrino interactions
must be rejected. In this paper, we first derive new limits on these
Non-Standard neutrino Interactions (NSIs) from LHC monojet data. For heavy NSI
mediators, these limits are much stronger than those coming from traditional
low-energy scattering or oscillation experiments for some flavor
structures. Monojet data alone can be used to infer the mass of the "missing
particle" from the shape of the missing energy distribution. In particular, 13
TeV LHC data will have sensitivity to DM masses greater than 1 TeV. In
addition to the monojet channel, NSI can be probed in multi-lepton searches
which we find to yield stronger limits at heavy mediator masses. The
sensitivity offered by these multi-lepton channels provide a method to reject
or confirm the DM hypothesis in missing energy searches.Comment: 11 pages, 7 figure
On the Direct Detection of Dark Matter Annihilation
We investigate the direct detection phenomenology of a class of dark matter
(DM) models in which DM does not directly interact with nuclei, {but rather}
the products of its annihilation do. When these annihilation products are very
light compared to the DM mass, the scattering in direct detection experiments
is controlled by relativistic kinematics. This results in a distinctive recoil
spectrum, a non-standard and or even absent annual modulation, and the ability
to probe DM masses as low as a 10 MeV. We use current LUX data to show
that experimental sensitivity to thermal relic annihilation cross sections has
already been reached in a class of models. Moreover, the compatibility of dark
matter direct detection experiments can be compared directly in
space without making assumptions about DM astrophysics, mass, or scattering
form factors. Lastly, when DM has direct couplings to nuclei, the limit from
annihilation to relativistic particles in the Sun can be stronger than that of
conventional non-relativistic direct detection by more than three orders of
magnitude for masses in a 2-7 GeV window.Comment: 4 pages, 3 figures, PRL versio
Gravitational recoil from spinning binary black hole mergers
The inspiral and merger of binary black holes will likely involve black holes
with both unequal masses and arbitrary spins. The gravitational radiation
emitted by these binaries will carry angular as well as linear momentum. A net
flux of emitted linear momentum implies that the black hole produced by the
merger will experience a recoil or kick. Previous studies have focused on the
recoil velocity from unequal mass, non-spinning binaries. We present results
from simulations of equal mass but spinning black hole binaries and show how a
significant gravitational recoil can also be obtained in these situations. We
consider the case of black holes with opposite spins of magnitude
aligned/anti-aligned with the orbital angular momentum, with the
dimensionless spin parameters of the individual holes. For the initial setups
under consideration, we find a recoil velocity of V = 475 \KMS a.
Supermassive black hole mergers producing kicks of this magnitude could result
in the ejection from the cores of dwarf galaxies of the final hole produced by
the collision.Comment: 8 pages, 8 figures, replaced with version accepted for publication in
Ap
Enabling I/O Automata Using Omniscient Archetypes
Many cyberinformaticians would agree that, had it not been for IPv6, the technical unification of digital-to-analog converters and Byzantine fault tolerance might never have occurred. Given the trends in constant-time theory, hackers worldwide famously note the study of randomized algorithms, which embodies the confirmed principles of cryptography. In our research we describe new game-theoretic archetypes (Sinner), showing that Byzantine fault toler- ance and the producer-consumer problem are mostly incompatible. Even though such a hypothesis might seem perverse, it fell in line with our expectations
Locating Boosted Kerr and Schwarzschild Apparent Horizons
We describe a finite-difference method for locating apparent horizons and
illustrate its capabilities on boosted Kerr and Schwarzschild black holes. Our
model spacetime is given by the Kerr-Schild metric. We apply a Lorentz boost to
this spacetime metric and then carry out a 3+1 decomposition. The result is a
slicing of Kerr/Schwarzschild in which the black hole is propagated and Lorentz
contracted. We show that our method can locate distorted apparent horizons
efficiently and accurately.Comment: Submitted to Physical Review D. 12 pages and 22 figure
Exploring Protein-Protein Interactions as Drug Targets for Anti-cancer Therapy with In Silico Workflows
We describe a computational protocol to aid the design of small molecule and peptide drugs that target protein-protein interactions, particularly for anti-cancer therapy. To achieve this goal, we explore multiple strategies, including finding binding hot spots, incorporating chemical similarity and bioactivity data, and sampling similar binding sites from homologous protein complexes. We demonstrate how to combine existing interdisciplinary resources with examples of semi-automated workflows. Finally, we discuss several major problems, including the occurrence of drug-resistant mutations, drug promiscuity, and the design of dual-effect inhibitors.Fil: Goncearenco, Alexander. National Institutes of Health; Estados UnidosFil: Li, Minghui. Soochow University; China. National Institutes of Health; Estados UnidosFil: Simonetti, Franco Lucio. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones BioquÃmicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones BioquÃmicas de Buenos Aires; ArgentinaFil: Shoemaker, Benjamin A. National Institutes of Health; Estados UnidosFil: Panchenko, Anna R. National Institutes of Health; Estados Unido
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