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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. We describe some of our mathematical results that predict such behavior and that form the basis for physical experiments in space. The results include cases of discontinuous dependence on data and symmetry-breaking type of behavior.
The broad objective of this work is to improve understanding of the internal structures and thermal and stress histories of the solid planets by combining results from analytical and computational modeling, and geophysical data analysis of gravity, topography and tectonic surface structures. During the past year we performed two quite independent studies in the attempt to explain the Mariner 10 magnetic observations of Mercury. In the first we revisited the possibility of crustal remanence by studying the conditions under which one could break symmetry inherent in Runcorn's model of a uniformly magnetized shell to produce a remanent signal with a dipolar form. In the second we applied a thin shell dynamo model to evaluate the range of intensity/structure for which such a planetary configuration can produce a dipole field consistent with Mariner 10 results. In the next full proposal cycle we will: (1) develop numerical and analytical and models of thin shell dynamos to address the possible nature of Mercury s present-day magnetic field and the demise of Mars magnetic field; (2) study the effect of degree-1 mantle convection on a core dynamo as relevant to the early magnetic field of Mars; (3) develop models of how the deep mantles of terrestrial planets are perturbed by large impacts and address the consequences for mantle evolution; (4) study the structure, compensation, state of stress, and viscous relaxation of lunar basins, and address implications for the Moon s state of stress and thermal history by modeling and gravity/topography analysis; and (5) use a three-dimensional viscous relaxation model for a planet with generalized vertical viscosity distribution to study the degree-two components of the Moon's topography and gravity fields to constrain the primordial stress state and spatial heterogeneity of the crust and mantle.
The apex of the Balloon-borne Experiment with a Superconducting Spectrometer program was reached with the Antarctic flight of BESS-Polar II, during the 2007-2008 Austral Summer, that obtained 24.5 days of data on over 4.7 billion cosmic-ray events. The US-Japan BESS Collaboration uses elementary particle measurements to study the early Universe and provides fundamental data on the spectra of light cosmic-ray elements and isotopes. BESS measures the energy spectra of cosmic-ray antiprotons to investigate signatures of possible exotic sources, such as dark-matter candidates, and searches for heavier anti-nuclei that might reach Earth from antimatter domains formed during symmetry breaking processes in the early Universe. Since 1993, BESS has carried out eleven high-latitude balloon flights, two of long duration, that together have defined the study of antiprotons below about 4 GeV, provided standard references for light element and isotope spectra, and set the most sensitive limits on the existence of anti-deuterons and anti-helium, The BESS-Polar II flight took place at Solar Minimum, when the sensitivity of the low-energy antiproton measurements to a primary source is greatest. The rich BESS-Polar II dataset more than doubles the combined data from all earlier BESS flights and has 10-20 times the statistics of BESS data from the previous Solar Minimum. Here, we summarize the scientific results of BESS program, focusing on the results obtained using data from the long-duration flights of BESS-Polar I (2004) and BESS-Polar II.
The apex of the Balloon-borne Experiment with a Superconducting Spectrometer (BESS) program was reached with the Antarctic flight of BESS-Polar II, during the 2007-2008 Austral Summer, that obtained 24.5 days of data on over 4.7 billion cosmic-ray events. The US-Japan BESS Collaboration uses elementary particle measurements to study the early Universe and provides fundamental data on the spectra of light cosmic-ray elements and isotopes. BESS measures the energy spectra of cosmic-ray antiprotons to investigate signatures of possible exotic sources, such as dark-matter candidates, and searches for heavier antinuclei that might reach Earth from antimatter domains formed during symmetry breaking processes in the early Universe. Since 1993, BESS has carried out eleven high-latitude balloon flights, two of long duration, that together have defined the study of antiprotons below about 4 GeV, provided standard references for light element and isotope spectra, and set the most sensitive limits on the existence of antideuterons and antihelium. The BESS-Polar II flight took place at Solar Minimum, when the sensitivity of the low-energy antiproton measurements to a primary source is greatest. The rich BESS-Polar II dataset more than doubles the combined data from all earlier BESS flights and has 10-20 times the statistics of BESS data from the previous Solar Minimum. Here, we summarize the scientific results of BESS program, focusing on the results obtained using data from the long-duration flights of BESS-Polar I (2004) and BESS-Polar II.
We explore the advantages offered by twin light beams produced in parametric down-conversion for precision measurement. The symmetry of these bipartite quantum states, even under losses, suggests that monitoring correlations between the divergent beams permits a high-precision inference of any symmetry-breaking effect, e.g., fiber birefringence. We show that the quantity of entanglement is not the key feature for such an instrument. In a lossless setting, scaling of precision at the ultimate "Heisenberg" limit is possible with photon counting alone. Even as photon losses approach 100% the precision is shot-noise limited, and we identify the crossover point between quantum and classical precision as a function of detected flux. The predicted hypersensitivity is demonstrated with a Bayesian simulation.
Galileo mission detected the magnetic anomalies originated from Galilean moons. These anomalies are likely generated in the moons interiors, under the influence of a strong ambient Jovian field. Among various possible generation mechanisms of the anomalies, we focus on magneto-convection and dynamos in the interiors via numerical simulation. To mimic the electromagnetic environment of the moons, we introduce in our numerical model an external uniform magnetic field B(sub 0) with a fixed orientation but varying field strength. Our results show that a finite B(sub 0) can substantially alter the dynamo processes inside the core. When the ambient field strength B(sub 0) increases to approximately 40% of the field generated by the pure dynamo action, the convective state in the core changes significantly: the convective flow decreases by 80% in magnitude, but the differential rotation becomes stronger in much of the fluid layer, leading to a stronger field generated in the core. The field morphologies inside the core tend to align with the ambient field, while the flow patterns show the symmetry-breaking effect under the influence of B(sub 0). Furthermore, the generated field tends to be temporally more stable.
This document introduces the exciting and fundamentally new science and astronomy that the European New Gravitational Wave Observatory (NGO) mission (derived from the previous LISA proposal) will deliver. The mission (which we will refer to by its informal name eLISA ) will survey for the first time the low-frequency gravitational wave band (about 0.1 mHz to 1 Hz), with sufficient sensitivity to detect interesting individual astrophysical sources out to z = 15. The measurements described here will address the basic scientific goals that have been captured in ESA s New Gravitational Wave Observatory Science Requirements Document ; they are presented here so that the wider scientific community can have access to them. The eLISA mission will discover and study a variety of cosmic events and systems with high sensitivity: coalescences of massive black holes binaries, brought together by galaxy mergers; mergers of earlier, less-massive black holes during the epoch of hierarchical galaxy and black-hole growth; stellar-mass black holes and compact stars in orbits just skimming the horizons of massive black holes in galactic nuclei of the present era; extremely compact white dwarf binaries in our Galaxy, a rich source of information about binary evolution and about future Type Ia supernovae; and possibly most interesting of all, the uncertain and unpredicted sources, for example relics of inflation and of the symmetry-breaking epoch directly after the Big Bang. eLISA s measurements will allow detailed studies of these signals with high signal-to-noise ratio, addressing most of the key scientific questions raised by ESA s Cosmic Vision programme in the areas of astrophysics and cosmology. They will also provide stringent tests of general relativity in the strong-field dynamical regime, which cannot be probed in any other way. This document not only describes the science but also gives an overview on the mission design and orbits. LISA s heritage in the eLISA design will be clear to those familiar with the previous proposal, as will its incorporation of key elements of hardware from the LISA Pathfinder mission, scheduled for launch by ESA in 2014. But eLISA is fundamentally a new mission, one that will pioneer the completely new science of low-frequency gravitational wave astronomy. 4 of
We discuss a particular secluded WIMP dark matter model consisting of neutral fermions as the dark matter candidate and a Proca-Wentzel (PW) field as a mediator. In the model that we consider here, dark matter WIMPs interact with standard model (SM) particles only through the PW field of approximately MeV-multi-GeV mass particles. The interactions occur via a U(1)' mediator, V'(sub mu), which couples to the SM by kinetic mixing with U(1) hypercharge bosons, B'(sub mu). One important difference between our model and other such models in the literature is the absence of an extra singlet scalar, so that the parameter with dimension of mass M(sup 2, sub V) is not related to a spontaneous symmetry breaking. This QED based model is also renormalizable. The mass scale of the mediator and the absence of the singlet scalar can lead to interesting astrophysical signatures. The dominant annihilation channels are different from those usually considered in previous work. We show that the GeV energy gamma-ray excess in the galactic center region, as derived from Fermi-LAT Gamma-ray Space Telescope data, can be attributed to such secluded dark matter WIMPs, given parameters of the model that are consistent with both the cosmological dark matter density and the upper limits on WIMP spin-independent elastic scattering. Secluded WIMP models are also consistent with suggested upper limits on a DM contribution to the cosmic-ray antiproton flux.
We present the results of a combined experimental and phase-field modeling study of pattern formation during freeze casting. Those studies use unidirectional freezing of simple binary liquid mixtures of water and sugars (sucrose and trehalose) in a temperature gradient, which suffice to produce hierarchical templated structures similar to those observed in more complex multi-component freeze-cast systems including lamellae, undulated ridges, and more exotic “jellyfish-like” substructures. Multiscale 3D phase-field simulations reproduce remarkably well those structures quantitatively and identify key properties of the ice-water interface that control their formation. They further reveal that lamellae form as a result of a novel symmetry-breaking secondary instability of partially faceted cellular structures and pinpoint additional secondary instability mechanisms giving rise to smaller-scale substructures.
The Asuka (A)-12236 meteorite has recently been classified as a CM carbonaceous chondrite of petrologic type 3.0/2.9 and is among the most primitive CM meteorites studied to date. Here, we report the concentrations, relative distributions, and enantiomeric ratios of amino acids in water extracts of the A-12236 meteorite and another primitive CM chondrite Elephant Moraine(EET) 96029 (CM2.7) determined by ultra-high-performance liquid chromatography time-of-flight mass spectrometry. EET 96029 was highly depleted in amino acids and dominated by glycine, while a wide diversity of two- to six-carbon aliphatic primary amino acids were identified in A-12236, which had a total amino acid abundance of 360 ± 18 nmol g-1, with most amino acids present without hydrolysis (free). The amino acid concentrations of A-12236 were double those previously measured in the CM2.7 Paris meteorite, consistent with A-12236 being a highly primitive and unheated CM chondrite. The high relative abundance of α-amino acids in A-12236 are consistent with formation by a Strecker-cyanohydrin dominated synthesis during a limited early aqueous alteration phase on the CM meteorite parent body. The presence of predominantly free glycine, a near racemic mixture of alanine (D/L ~0.93 to 0.96), and elevated abundances of several terrestrially rare non-protein amino acids including α-amino isobutyric acid (α-AIB) and racemic isovaline, indicate that these amino acids in A-12236 are extraterrestrial in origin. Given a lack of evidence for biological amino acid contamination in A-12236, it is possible that some of the L-enantiomeric excesses (Lee ~34 to 64%) of the protein amino acids aspartic and glutamic acids and serine are indigenous to the meteorite; however, isotopic measurements are needed for confirmation. In contrast to more aqueously altered CMs of petrologic types ≤ 2.5, no L-isovaline excesses were detected in A-12236. This observation strengthens the hypothesis that extensive parent body aqueous activity is required to produce or amplify the large L-isovaline excesses that cannot be explained solely by exposure to circularly polarized radiation or other chiral symmetry breaking mechanisms prior to incorporation into the asteroid parent body.
We present the results of a combined experimental and phase-field modeling study of pattern formation during freeze casting. Those studies use unidirectional freezing of simple binary liquid mixtures of water and sugars (sucrose and trehalose) in a temperature gradient, which suffice to produce hierarchical templated structures similar to those observed in more complex multi-component freeze-cast systems including lamellae, undulated ridges, and more exotic “jellyfish-like” substructures. Multiscale 3D phase-field simulations reproduce remarkably well those structures quantitatively and identify key properties of the ice-water interface that control their formation. They further reveal that lamellae form as a result of a novel symmetry-breaking secondary instability of partially faceted cellular structures and pinpoint additional secondary instability mechanisms giving rise to smaller-scale substructures.
We are developing Mltool++ package of software programs for machine learning (ML). Given the MLtool Python code, we create a faster C++ code with the potential for parallelization. We have extracted materials data from the literature. One dataset contains melting temperatures of stoichiometric 1:1 metallic compounds XZ, composed by elements X={Al, Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, W} and Z={Co, Ni, Cu, Rh, Pd, Ag, Ir, Pt, Au}, and another contains solid-solid symmetry-breaking phase transition temperatures. We studied dependences of temperatures on composition, found several correlations, and parametrized them by analytical functions. Mltool++ package is generic and applicable to any tabulated numeric data.
We discuss recent progress in Tensor Lattice Field Theory and economical, symmetry preserving, truncations suitable for quantum computations or simulations. We focus on spin and gauge models with continuous Abelian symmetries such as the Abelian Higgs model and emphasize noise-robust implementations of Gauss's law. We discuss recent progress concerning the comparison between field digitizations and character expansions, symmetry breaking in tensor language, wave-packet preparation and possible new implementations of Abelian models using Rydberg atoms.
Scalar bosons composed of a pair of chiral fermions in a non-confining potential have an effective Yukawa coupling, $g$, to free external chiral fermions. At large distance a Feynman loop of external fermions generates a scale invariant potential, $V_{loop}\propto -g^2/{\rho^{2}}$, for separation $\rho$, which acts on valence fermions. This generally forces the $s$-wave ground state to deform to a static, zero mass, configuration, and for slowly running, perturbative $g$, a large external "shroud" wave function forms. This is related to old results of Landau and Lifshitz in quantum mechanics. The massless composite scalar boson ground state is then an extended object. Infra-red effects can generate a small mass for the system. This points to a perturbative BEH-boson composed of top and anti-top quarks and a novel dynamical mechanism for spontaneous electroweak symmetry breaking.
The Higgs boson trilinear and quartic self-couplings are directly related to the shape of the Higgs potential; measuring them with precision is extremely important, as they provide invaluable information on the electroweak symmetry breaking and the electroweak phase transition. In this paper, we perform a detailed analysis of double Higgs boson production, through the gluon gluon fusion process, in the most promising decay channels di-bottom-quark di-photons, di-bottom-quark di-tau, and four-bottom-quark for several future colliders: the HL-LHC at 14 TeV and the FCC-hh at 100 TeV, assuming respectively 3 inverse ab and 30 inverse ab of integrated luminosity. In the HL LHC scenario, we expect an upper limit on the di Higgs cross section production of 0.76 at 95% confidence level, corresponding to a significance of 2.8 sigma. In the FCC-hh scenario, depending on the assumed detector performance and systematic uncertainties, we expect that the Higgs self-coupling will be measured with a precision in the range 4.8-8.5% at 95% confidence level.
One of the central goals of the physics program at the future colliders is to elucidate the origin of electroweak symmetry breaking, including precision measurements of the Higgs sector. This includes a detailed study of Higgs boson (H) pair production, which can reveal the H self-coupling. Since the discovery of the Higgs boson, a large campaign of measurements of the properties of the Higgs boson has begun and many new ideas have emerged during the completion of this program. One such idea is the use of highly boosted and merged hadronic decays of the Higgs boson ($\mathrm{H}\to\mathrm{b}\bar{\mathrm{b}}$, $\mathrm{H}\to\mathrm{W}\mathrm{W}\to\mathrm{q}\bar{\mathrm{q}}\mathrm{q}\bar{\mathrm{q}}$) with machine learning methods to improve the signal-to-background discrimination. In this white paper, we champion the use of these modes to boost the sensitivity of future collider physics programs to Higgs boson pair production, the Higgs self-coupling, and Higgs-vector boson couplings. We demonstrate the potential improvement possible at the Future Circular Collider in hadron mode, especially with the use of graph neural networks.
Magnetic topological defects are energetically stable spin configurations characterized by symmetry breaking. Vortices and skyrmions are two well-known examples of 2D spin textures that have been actively studied for both fundamental interest and practical applications. However, experimental evidence of the 3D spin textures has been largely indirect or qualitative to date, due to the difficulty of quantitively characterizing them within nanoscale volumes. Here, we develop soft x-ray vector ptychography to quantitatively image the 3D magnetization vector field in a frustrated superlattice with 10 nm spatial resolution. By applying homotopy theory to the experimental data, we quantify the topological charge of hedgehogs and anti-hedgehogs as emergent magnetic monopoles and probe their interactions inside the frustrated superlattice. We also directly observe virtual hedgehogs and anti-hedgehogs created by magnetically inert voids. We expect that this new quantitative imaging method will open the door to study 3D topological spin textures in a broad class of magnetic materials. Our work also demonstrates that magnetically frustrated superlattices could be used as a new platform to investigate hedgehog interactions and dynamics and to exploit optimized geometries for information storage and transport applications.
A future Higgs Factory will provide improved precision on measurements of Higgs couplings beyond those obtained by the LHC, and will enable a broad range of investigations across the fields of fundamental physics, including the mechanism of electroweak symmetry breaking, the origin of the masses and mixing of fundamental particles, the predominance of matter over antimatter, and the nature of dark matter. Future colliders will measure Higgs couplings to a few per cent, giving a window to beyond the Standard Model (BSM) physics in the 1-10 TeV range. In addition, they will make precise measurements of the Higgs width, and characterize the Higgs self-coupling. Here, this report details the work of the EF01 and EF02 working groups for the Snowmass 2021 study.