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Neutron-scattering-based evidence for interacting magnetic excitons in LaCo O 3
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Density of states of two-dimensional systems with long-range logarithmic interactions
We investigate a single-particle density of states (DOS) in strongly disordered two- dimensional high dielectric permittivity systems with logarithmic Coulomb interaction between particles. We derive self-consistent DOS at zero temperature and show that it is appreciably suppressed as compared to the DOS expected from the Efros-Shklovskii approach.We carry out zero- and finite-temperature Monte Carlo numerical studies of the DOS and find the perfect agreement between the numerical and analytical results at zero temperature, observing, in particular, a hardening of the Coulomb gap with the increasing electrostatic screening length. At finite temperatures, we reveal a striking scaling of the DOS as a function of energy normalized to the temperature of the system.
Final-state interactions in neutrino-induced proton knockout from argon in MicroBooNE
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Exploring the anomaly in the interaction cross section and matter radius of 23 O
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2 H ( e , e ′ p ) observables using a Regge model parametrization of final-state interactions
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Properties of trapped neutrons interacting with realistic nuclear Hamiltonians
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Giant and pigmy dipole resonances in 4 He, 16,22 O, and 40 Ca from chiral nucleon-nucleon interactions
We combine the coupled-cluster method and the Lorentz integral transform for the computation of inelastic reactions into the continuum. We show that the bound-state-like equation characterizing the Lorentz integral transform method can be reformulated based on extensions of the coupled-cluster equation-of-motion method, and we discuss strategies for viable numerical solutions. Starting from a chiral nucleon-nucleon interaction at next-to-next-to-next-to-leading order, we compute the giant dipole resonances of 4 He, 16,22 O, and 40 Ca, truncating the coupled-cluster equation-of-motion method at the two-particle–two-hole excitation level. Within this scheme, we find a low-lying E1 strength in the neutron-rich 22 O nucleus, which compares fairly well with data from Leistenschneider et al. [Phys. Rev. Lett. 86, 5442 (2001)]. We also compute the electric dipole polarizability in 40 Ca. Deficiencies of the employed Hamiltonian lead to overbinding, too-small charge radii, and a too-small electric dipole polarizability in 40 Ca.
Differential cross section measurement of charged current ν e interactions without final-state pions in MicroBooNE
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Strongly interacting dark matter: Self-interactions and keV lines
Herein, we consider a simple supersymmetric hidden sector: pure SU ( N ) gauge theory. Dark matter is made up of hidden glueballinos with mass m X and hidden glueballs with mass near the confinement scale Λ . For m X ~ 1 TeV and Λ ~ 100 MeV , the glueballinos freeze out with the correct relic density and self-interact through glueball exchange to resolve small-scale structure puzzles. An immediate consequence is that the glueballino spectrum has a hyperfine splitting of order Λ 2 / m X ~ 10 keV . We illustrate that the radiative decays of the excited state can explain the observed 3.5 keV x-ray line signal from clusters of galaxies, Andromeda, and the Milky Way.
Contact-interaction Faddeev equation and, inter alia , proton tensor charges
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Search for active-sterile neutrino mixing using neutral-current interactions in NOvA
Here, we report results from the first search for sterile neutrinos mixing with active neutrinos through a reduction in the rate of neutral-current interactions over a baseline of 810 km between the NOvA detectors. Analyzing a 14-kton detector equivalent exposure of 6.05 × 10 20 protons-on-target in the NuMI beam at Fermilab, we observe 95 neutral-current candidates at the Far Detector compared with 83.5 ± 9.7(stat) ± 9.4(syst) events predicted assuming mixing only occurs between active neutrino species. No evidence for νμ→νs transitions is found. Interpreting these results within a 3+1 model, we place constraints on the mixing angles θ 24 < 20.8° and θ 34 < 31.2° at the 90% C.L. for 0.05 eV 2 ≤ Δm 41 2 ≤ 0.5 eV 2 , the range of mass splittings that produce no significant oscillations over the Near Detector baseline.
Nonlinear Quantum Optics in a Waveguide: Distinct Single Photons Strongly Interacting at the Single Atom Level
We propose a waveguide-QED system where two single photons of distinct frequency or polarization interact strongly. The system consists of a single ladder-type three level atom coupled to a waveguide. When both optical transitions are coupled strongly to the waveguide's mode, we show that a control photon tuned to the upper transition induces a {pi} phase shift and tunneling of a probe photon tuned to the otherwise reflective lower transition. Furthermore, the system exhibits single photon scattering by a classical control beam. Waveguide-QED schemes could be an alternative to high quality cavities or dense atomic ensembles in quantum information processing.
Observation of Shock Waves in a Strongly Interacting Fermi Gas
We study collisions between two strongly interacting atomic Fermi gas clouds. We observe exotic nonlinear hydrodynamic behavior, distinguished by the formation of a very sharp and stable density peak as the clouds collide and subsequent evolution into a boxlike shape. We model the nonlinear dynamics of these collisions by using quasi-1D hydrodynamic equations. Our simulations of the time-dependent density profiles agree very well with the data and provide clear evidence of shock wave formation in this universal quantum hydrodynamic system.
Band Formation in a Molecular Quantum Well via 2D Superatom Orbital Interactions
By scanning tunneling microscopy and spectroscopy, we study nearly free electron band formation of the σ*lowest unoccupied molecular orbital of C₆F₆ on a Cu(111) surface. In fractal islands, the lowest unoccupied molecular orbital energy systematically stabilizes with the number of interacting near-neighbor C₆F₆ molecules. Density functional theory calculations reveal the origin of effective intermo- lecular orbital overlap in the previously unrecognized superatom character of the σ*orbital of ₆F₆ molecules. The discovery of superatom orbitals in planar molecules offers a new universal principle for effective band formation, which can be exploited in designing organic semiconductors with nearly free electron properties
Beyond-standard-model tensor interaction and hadron phenomenology
Here, we evaluate the impact of recent developments in hadron phenomenology on extracting possible fundamental tensor interactions beyond the standard model. We show that a novel class of observables, including the chiral-odd generalized parton distributions, and the transversity parton distribution function can contribute to the constraints on this quantity. Experimental extractions of the tensor hadronic matrix elements, if sufficiently precise, will provide a, so far, absent testing ground for lattice QCD calculations.
Interaction of an ultrarelativistic electron bunch train with a W-band accelerating structure: High power and high gradient
Electron beam interaction with high frequency structures (beyond microwave regime) has a great impact on future high energy frontier machines. We report on the generation of multimegawatt pulsed rf power at 91 GHz in a planar metallic accelerating structure driven by an ultrarelativistic electron bunch train. This slow-wave wakefield device can also be used for high gradient acceleration of electrons with a stable rf phase and amplitude which are controlled by manipulation of the bunch train. To achieve precise control of the rf pulse properties, a two-beam wakefield interferometry method was developed in which the rf pulse, due to the interference of the wakefields from the two bunches, was measured as a function of bunch separation. As a result, measurements of the energy change of a trailing electron bunch as a function of the bunch separation confirmed the interferometry method.