Calculating composite-particle spectra in Hamiltonian formalism and demonstration in 2-flavor QED1+1d_{1+1\text{d}}

We consider three distinct methods to compute the mass spectrum of gauge theories in the Hamiltonian formalism: (1) correlation-function scheme, (2) one-point-function scheme, and (3) dispersion-relation scheme. The first one corresponds to the conventional Euclidean method in the Monte Carlo simulations. The second one uses the boundary effect to efficiently compute the mass spectrum. The third one constructs the excited states and fits their energy using the dispersion relation with selecting quantum numbers. Each method has its pros and cons, and we clarify such properties in their applications to the mass spectrum for the 2-flavor massive Schwinger model at $m/g=0.1$ and $\theta=0$ using the density-matrix renormalization group (DMRG). We note that the multi-flavor Schwinger model at small mass $m$ is a strongly-coupled field theory even after the bosonizations, and thus it deserves to perform the first-principles numerical calculations. All these methods mostly agree and identify the stable particles, pions $\pi_a$ ($J^{PG}=1^{-+}$), sigma meson $\sigma$ ($J^{PG}=0^{++}$), and eta meson $\eta$ ($J^{PG}=0^{--}$). In particular, we find that the mass of $\sigma$ meson is lighter than twice the pion mass, and thus $\sigma$ is stable against the decay process, $\sigma \to \pi\pi$. This is consistent with the analytic prediction using the WKB approximation, and, remarkably, our numerical results are so close to the WKB-based formula between the pion and sigma-meson masses, $M_\sigma/M_\pi=\sqrt{3}$.Comment: 40 pages, 16 figure

Uniaxial negative thermal expansion in an orthorhombic superconductor CoZr3

We investigated the temperature evolution of crystal structure of orthorhombic CoZr3, which is a superconductor with a transition temperature of 4.3 K, by synchrotron and laboratory (CuK{\alpha}) X-ray diffraction. Uniaxial negative thermal expansion along the c-axis, which is similar to that observed in tetragonal CoZr2, has been observed at a wide temperature range of T = 90-800 K in CoZr3, while a-and b-axis exhibit positive thermal expansion.Comment: 9 pages, 3 figures, supplemental material

Calculating composite-particle spectra in Hamiltonian formalism and demonstration in 2-flavor QED1+1d

Abstract We consider three distinct methods to compute the mass spectrum of gauge theories in the Hamiltonian formalism: (1) correlation-function scheme, (2) one-point-function scheme, and (3) dispersion-relation scheme. The first one examines spatial correlation functions as we do in the conventional Euclidean Monte Carlo simulations. The second one uses the boundary effect to efficiently compute the mass spectrum. The third one constructs the excited states and fits their energy using the dispersion relation with selecting quantum numbers. Each method has its pros and cons, and we clarify such properties in their applications to the mass spectrum for the 2-flavor massive Schwinger model at m/g = 0.1 and θ = 0 using the density-matrix renormalization group (DMRG). We note that the multi-flavor Schwinger model at small mass m is a strongly coupled field theory even after the bosonizations, and thus it deserves to perform the first-principles numerical calculations. All these methods mostly agree and identify the stable particles, pions π a (J PG = 1 −+), sigma meson σ (J PG = 0++), and eta meson η (J PG = 0 −− ). In particular, we find that the mass of σ meson is lighter than twice the pion mass, and thus σ is stable against the decay process, σ → ππ. This is consistent with the analytic prediction using the WKB approximation, and, remarkably, our numerical results are so close to the WKB-based formula between the pion and sigma-meson masses, M σ /M π = 3 $$\sqrt{3}$$

Metastable Phase Formation from Nd-Dy-Fe-B Undercooled Melt

Abstract Nd 10-x Dy x Fe 85 B 5 (x = 0-3) alloy samples were melted and then solidified in the containerless state of a drop tube at oxygen partial pressure of 10 -1 Pa. The calculated cooling rate of the spherical sample was over 10 3 K/s. The Nd 10 Fe 85 B 5 sample consists of the Nd 2 Fe 17 B x metastable phase together with the α-Fe dendrite. The metastable phase was partially decomposed into small grains of Nd 2 Fe 14 B and α-Fe phases by a solid state decomposition reaction. The substitution of Dy for Nd in the range from 10 to 20 atomic percent was effective to suppress the primary formation of the α-Fe dendrite and to promote the formation of the RE 2 Fe 17 B x metastable phase. When the substitution rate of Dy increased to 30 atomic percent, a large amount of the α-Fe dendrite was formed because an oxide layer of rare earth elements was generated at the sample surface due to the easy oxidization tendency of Dy

International Conference CoMFoS15

This book focuses on mathematical theory and numerical simulation related to various aspects of continuum mechanics, such as fracture mechanics, elasticity, plasticity, pattern dynamics, inverse problems, optimal shape design, material design, and disaster estimation related to earthquakes. Because these problems have become more important in engineering and industry, further development of mathematical study of them is required for future applications. Leading researchers with profound knowledge of mathematical analysis from the fields of applied mathematics, physics, seismology, engineering, and industry provide the contents of this book. They help readers to understand that mathematical theory can be applied not only to different types of industry, but also to a broad range of industrial problems including materials, processes, and products

Stiffness of Human Hair Correlates with the Fractions of Cortical Cell Types

(1) Background: The objective of this work was to elucidate the hair microstructure which correlates with the stiffness of human hair fibers. (2) Methods: Bending moduli of hair fibers were evaluated for the hair samples from 156 Japanese female subjects. Hair transverse sections were dual-stained with fluorescent dyes which can stain para- and ortho-like cortical cells separately, and observed under a fluorescence light microscope. Atomic force microscopy nanoindentation measurements were performed to examine the modulus inside macrofibrils. (3) Results: The difference in bending moduli between the maximum and the minimum values was more than double. The hair of high bending modulus was rich in para-like cortical cells and the bending modulus significantly correlated with the fraction of para-like cortical cells to the whole cortex. On the other hand, the elastic moduli inside macrofibrils were almost same for the para- and ortho-like cortical cells. (4) Conclusions: Hair bending modulus depends on the fractions of the constitutional cortical cell types. The contribution of the intermacrofibrillar materials, which differed in their morphologies and amounts of para- and ortho-like cortical cells, is plausible as a cause of the difference in the modulus of the cortical cell types

A Variational Analysis of Flow-Reversal Condition in a Turbulent Swirling Flow Using the Bulk-Helicity Concept, with Special Reference to Experimental Observations

特集 乱数数値シミュレーションと流れの設計(TSFD