Fermion Mass Hierarchy and Mixing in simplified Grand Gauge-Higgs Unification

Grand gauge-Higgs unification of five dimensional SU(6) gauge theory on an orbifold $S^1 / Z_2$ with localized gauge kinetic terms is discussed. The Standard model (SM) fermions on the boundaries and some massive bulk fermions coupling to the SM fermions are introduced. The number of the bulk fermions is reduced to realize perturbative gauge coupling unification, which could not be done in the previous model. Although this reduction will lead to the additional generation mixings in the bulk which makes our analysis more complicated and nontrivial, the generation mixing of the SM fermions is reproduced in addition to the SM fermion mass hierarchy by mild tuning the bulk masses and parameters of the localized gauge kinetic terms.Comment: 21 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:1911.0346

Schemes for nondestructive quantum gas microscopy of single atoms in an optical lattice

We propose a quantum gas microscope for ultracold atoms that enables nondestructive atom detection, thus evading higher-band excitation and change of the internal degrees of freedom. We show that photon absorption of a probe beam cannot be ignored even in dispersive detection to obtain a signal-to-noise ratio greater than unity because of the shot noise of the probe beam under a standard measurement condition. The first scheme we consider for the nondestructive detection, applicable to an atom that has an electronic ground state without spin degrees of freedom, is to utilize a magic-wavelength condition of the optical lattice for the transition for probing. The second is based on the dispersive Faraday effect and squeezed quantum noise and is applicable to an atom with spins in the ground state. In this second scheme, a scanning microscope is adopted to exploit the squeezed state and reduce the effective losses. Application to ultracold ytterbium atoms is discussed

Observation of spin-exchange dynamics between itinerant and localized ¹⁷¹Yb atoms

We report on the observation of the spin-exchange dynamics of ¹⁷¹Yb atoms in the ground state ¹S₀ and in the metastable state ³P₀. We implement the mixed-dimensional two-orbital system using near-resonant and magic-wavelength optical lattices, where the ¹S₀ and ³P₀ atoms are itinerant in a one-dimensional tube and localized in three dimensions, respectively. By exploiting an optical Stern-Gerlach method, we observe the spin depolarization of the ¹S₀ atoms induced by the spin-exchange interaction with the ³P₀ atom. Our work could pave the way to the quantum simulation of the Kondo effect

Elastic Convection in Vibrated Viscoplastic Fluids

We observe a new type of behavior in a shear thinning yield stress fluid: freestanding convection rolls driven by vertical oscillation. The convection occurs without the constraint of container boundaries yet the diameter of the rolls is spontaneously selected for a wide range of parameters. The transition to the convecting state occurs without hysteresis when the amplitude of the plate acceleration exceeds a critical value. We find that a non-dimensional stress, the stress due to the inertia of the fluid normalized by the yield stress, governs the onset of the convective motion.Comment: 4 pages, 6 figure

On Detection of Black Hole Quasi-Normal Ringdowns: Detection Efficiency and Waveform Parameter Determination in Matched Filtering

Gravitational radiation from a slightly distorted black hole with ringdown waveform is well understood in general relativity. It provides a probe for direct observation of black holes and determination of their physical parameters, masses and angular momenta (Kerr parameters). For ringdown searches using data of gravitational wave detectors, matched filtering technique is useful. In this paper, we describe studies on problems in matched filtering analysis in realistic gravitational wave searches using observational data. Above all, we focus on template constructions, matches or signal-to-noise ratios (SNRs), detection probabilities for Galactic events, and accuracies in evaluation of waveform parameters or black hole hairs. We have performed matched filtering analysis for artificial ringdown signals which are generated with Monte-Carlo technique and injected into the TAMA300 observational data. It is shown that with TAMA300 sensitivity, the detection probability for Galactic ringdown events is about 50% for black holes of masses greater than $20 M_{\odot}$ with SNR $> 10$. The accuracies in waveform parameter estimations are found to be consistent with the template spacings, and resolutions for black hole masses and the Kerr parameters are evaluated as a few % and $\sim 40$, respectively. They can be improved up to $< 0.9$ and $< 24$ for events of ${\rm SNR} \ge 10$ by using fine-meshed template bank in the hierarchical search strategy.Comment: 10 pages, 10 figure

Bragg x-ray ptychography of a silicon crystal: Visualization of the dislocation strain field and the production of a vortex beam

We experimentally demonstrate the visualization of nanoscale dislocation strain fields in a thick silicon single crystal by a coherent diffraction imaging technique called Bragg x-ray ptychography. We also propose that the x-ray microbeam carrying orbital angular momentum is selectively produced by coherent Bragg diffraction from dislocation singularities in crystals. This work not only provides us with a tool for characterizing dislocation strain fields buried within extended crystals but also opens up new scientific opportunities in femtosecond spectroscopy using x-ray free-electron lasers.Yukio Takahashi, Akihiro Suzuki, Shin Furutaku, Kazuto Yamauchi, Yoshiki Kohmura, and Tetsuya Ishikawa, Phys. Rev. B 87, 121201, 2013

High-resolution and high-sensitivity phase-contrast imaging by focused hard x-ray ptychography with a spatial filter

We demonstrate high-resolution and high-sensitivity x-ray phase-contrast imaging of a weakly scattering extended object by scanning coherent diffractive imaging, i.e., ptychography, using a focused x-ray beam with a spatial filter. We develop the x-ray illumination optics installed with the spatial filter to collect coherent diffraction patterns with a high signal-to-noise ratio. We quantitatively visualize the object with a slight phase shift ([formula omitted]) at spatial resolution better than 17 nm in a field of view larger than [formula omitted]. The present coherent method has a marked potential for high-resolution and wide-field-of-view observation of weakly scattering objects such as biological soft tissues.Yukio Takahashi, Akihiro Suzuki, Shin Furutaku, Kazuto Yamauchi, Yoshiki Kohmura, and Tetsuya Ishikawa, "High-resolution and high-sensitivity phase-contrast imaging by focused hard x-ray ptychography with a spatial filter", Appl. Phys. Lett. 102, 094102 (2013) https://doi.org/10.1063/1.4794063