Progress of Theoretical and Experimental Physics

https://academic.oup.com/ptep

List of Papers (Total 884)

Thermodynamics for pure SU(2) gauge theory using gradient flow

We study the equation of state of pure SU(⁠|$2$|⁠) gauge theory using Monte Carlo simulations. The scale setting of lattice parameters has been carried by using the gradient flow. We propose a reference scale |$t_0$| for the SU(⁠|$2$|⁠) gauge theory satisfying |$t^2 \langle E \rangle|_{t=t_0} =0.1$|⁠, which is fixed by a natural scaling down of the standard |$t_0$| scale for the...

Gamma-ray spectrum from thermal neutron capture on gadolinium-157

We have measured the |$\gamma$|-ray energy spectrum from the thermal neutron capture, |${}^{157}$|Gd|$(n,\gamma)$|⁠, on an enriched |$^{157}$|Gd target (Gd|$_{2}$|O|$_{3}$|⁠) in the energy range from 0.11 MeV up to about 8 MeV. The target was placed inside the germanium spectrometer of the ANNRI detector at J-PARC and exposed to a neutron beam from the Japan Spallation Neutron...

Exact solutions of primordial gravitational waves

Future projects for the detection of gravitational waves are expected to have sufficient sensitivity to detect the primordial gravitational waves, which may be useful to get new insight into the very early universe. It is essential to analyze the evolution equation of gravitational waves in order to estimate the present field strength of the primordial gravitational waves. In...

Mixed-mode oscillation-incrementing bifurcations and a devil’s staircase from a nonautonomous, constrained Bonhoeffer–van der Pol oscillator

In this study, we analyze mixed-mode oscillation-incrementing bifurcations (MMOIBs) generated in the nonautonomous, constrained Bonhoeffer–van der Pol oscillator proposed by Kousaka et al. [Physica D 353–354, 48 (2017)]. Specifically, we investigate MMOIBs occurring in the |$1^4$|–|$1^5$| and |$1^1$|–|$1^2$| regions. These two kinds of MMOIBs exhibit qualitatively different MMO...

Adiabatic approach to large-amplitude collective motion with the higher-order collective-coordinate operator

We propose a new set of equations to determine the collective Hamiltonian including the second-order collective-coordinate operator on the basis of the adiabatic self-consistent collective-coordinate (ASCC) theory. We illustrate, with the two-level Lipkin model, that the collective operators including the second-order one are self-consistently determined. We compare the results...

Thermal fluctuations of charged black holes in gravity’s rainbow

Quantum fluctuation effects have an irrefutable role in high-energy physics. Such fluctuation can be often regarded as a correction of the infrared (IR) limit. In this paper, the effects of the first-order correction of entropy, caused by thermal fluctuation, on the thermodynamics of charged black holes in gravity’s rainbow will be discussed. It will be shown that such correction...

Asymptotic behavior of Nambu–Bethe–Salpeter wave functions for scalar systems with a bound state

We study the asymptotic behaviors of the Nambu–Bethe–Salpeter (NBS) wave functions, which are important for the HAL QCD potential method to extract hadron interactions, in the case that a bound state exists in the system. We consider the complex scalar particles, two of which lead to the formation of a bound state. In the case of the two-body system, we show that the NBS wave...

Development of the measurement of radium using a germanium detector with molecular recognition resin

High-purity germanium (HPGe) detectors are widely used for the measurement of low concentrations of radioactivity. For the Super-Kamiokande Gadolinium project, the concentration of radium in Gd|$_2$|(SO|$_4$|⁠)|$_3{\cdot}$|8H|$_2$|O is determined by using HPGe detectors. The amount of the sample is generally limited by the size of the sample space of an HPGe detector. This leads...

Long-term dynamics of cosmological axion strings

We present the results of a new field-theoretic simulation of cosmological axion strings, which are eight times longer than previous ones. We have upgraded our simulation of physical strings in Hiramatsu et al. [Phys. Rev. D 83, 123531 (2011)] in terms of the number of grids as well as the suite of analyses. These improvements enable us to monitor a variety of quantities...

Family unification in special grand unification

We discuss family unification in grand unified theory (GUT) based on an |$SU(19)$| GUT gauge group broken to its subgroups, including a special subgroup. In the |$SU(19)$| GUT on the six-dimensional (6D) orbifold space |$M^4\times T^2/\mathbb{Z}_2$|⁠, three generations of the 4D Standard Model Weyl fermions can be embedded into 6D bulk Weyl fermions in an |$SU(19)$| second-rank...

Perturbative/nonperturbative aspects of Bloch electrons in a honeycomb lattice

We revisit the spectral problem for Bloch electrons in a two-dimensional bipartite honeycomb lattice under a uniform magnetic field. It is well known that such a honeycomb structure is realized in graphene. We present a systematic framework to compute the perturbative magnetic flux expansions near two distinct band edges. We then analyze the nonperturbative bandwidth of the...

Massive dual gauge field and confinement in Minkowski space: Magnetic charge

Gauge field configuration for a magnetic monopole and its dual configuration are studied in SU(2) gauge theory. We present a relation between the monopole field and its dual field. Since these fields can become massive, their massive Lagrangians are derived. In the dual case, an additional term appears. We show that this term is necessary to produce a linear potential between a...

On statistical independence and no-correlation for a pair of random variables taking two values: Classical and quantum

It is well known that when a pair of random variables is statistically independent, it has no-correlation (zero covariance, $$E[XY] - E[X]E[Y] = 0$$), and that the converse is not true. However, if both of these random variables take only two values, no-correlation entails statistical independence. We provide here a general proof. We subsequently examine whether this equivalence...

A new route to negative refractive index from topological metals

We discuss the possibility of realizing a negative refractive index in Weyl/Dirac semimetals. We consider the Maxwell equations with the plasma gap and chiral magnetic effect. By computing the dispersion relations of electromagnetic waves, we show that the refractive index becomes negative at frequencies (just) below the plasma frequency. We find that the axial anomaly, or, more...

Understanding the muon anomalous magnetic moment in light of a flavor symmetry-based Minimal Supersymmetric Standard Model

We investigate whether the Minimal Supersymmetric Standard Model with the scalar masses of the third generation distinct from the first two, in order to be able to accommodate the muon anomalous magnetic moment, is consistent with the latest results from LHCb, direct collider bounds from the ATLAS and CMS experiments. In particular, we show that this class of models allows for...

Gradient flow and the renormalization group

We investigate the renormalization group (RG) structure of the gradient flow. Instead of using the original bare action to generate the flow, we propose to use the effective action at each flow time. We write down the basic equation for scalar field theory that determines the evolution of the action, and argue that the equation can be regarded as an RG equation if one makes a...

Local B-model Yukawa couplings from A-twisted correlators

Using the exact formula for the A-twisted correlation functions of the 2D $$\mathcal{N}=(2,2)$$ gauged linear sigma model, we reconsider the computation of the B-model Yukawa couplings of the local toric Calabi–Yau varieties. Our analysis is based on an exact result that has been evaluated from the supersymmetric localization technique and careful treatment of its application. We...

Single-pole nature of the detectable Lambda(1405)

We have investigated the single-pole nature of the detectable $$\Lambda(1405)$$ in detail, by employing a chiral model having double poles of a $$\bar KN$$–$$\pi \Sigma$$ coupled-channel $$T$$-matrix. The effects of the first pole and the second pole on the observed $$\pi \Sigma$$ mass spectrum in the $$\Lambda(1405)$$ region have been analyzed almost separately. It is concluded...

BPS Cho–Maison monopole

We present exact solutions to the Cho–Maison magnetic monopole in a family of effective electroweak models that have a Bogomol’nyi–Prasad–Sommerfield limit. We find that the lower bound to the mass of the magnetic monopole is $$M \geq 2\pi v/ g \approx 2.37\,\,\mathrm{TeV}$$. We argue that this bound holds universally, not just in theories with a BPS limit.

Self-similar fluctuations of classical origin in level-spacing statistics of quantum lemon billiards

Extending the study of Makino et al., Phys. Rev. E 63, 056203 (2001), the statistical properties of the energy levels are investigated for the one-parameter family of lemon-shaped quantal billiards, whose classical phase space consists of regular and chaotic regions. As the parameter is varied, the classical dynamical system repeats the bifurcations which cause part of the phase...

Majorana neutrino masses in the scenario of gauge–Higgs unification

In this paper we consider possible mechanisms to generate small Majorana neutrino masses for active neutrinos in the scenario of gauge–Higgs unification, a candidate for physics beyond the standard model. We stress that it is non-trivial to find a gauge-invariant operator, responsible for the Majorana masses, which is the counterpart of the well-known $$\mathrm{SU(2)}_L \times...

First demonstration of gamma-ray imaging using a balloon-borne emulsion telescope

We describe the precise gamma-ray observation project Gamma-Ray Astro-Imager with Nuclear Emulsion (GRAINE), which uses balloon-borne emulsion gamma-ray telescopes. The emulsion telescope realizes observations with high angular resolution, polarization sensitivity, and large aperture area in the 0.01–100 GeV energy region. We report on the data analysis of emulsion tracks and the...

Complete mixed-mode oscillation synchronization in weakly coupled nonautonomous Bonhoeffer–van der Pol oscillators

We investigate completely and incompletely synchronized mixed-mode oscillations (MMOs) generated by weakly coupled nonautonomous Bonhoeffer–van der Pol oscillators. We consider two identical oscillators that generate MMOs and MMO-incrementing bifurcations (MMOIBs), connected by a large inductor. Our numerical results indicate that the chaos in these two oscillators cannot be...