Lost Origins of the Third Generation of Quarks: Theory, Philosophy, and Experiment

Physicists generally attribute the introduction of a third generation of quarks (the "top" and "bottom" quarks) into the standard model of the elementary particles to a 1973 paper by Makoto Kobayashi and Toshihide Maskawa. I describe the historical background to that paper, emphasizing the largely forgotten role of theorists at Nagoya University and the "Nagoya model" they developed. Several of the authors of the Nagoya model embraced the philosophy of dialectical materialism, and I discuss the role that such metaphysical commitments play in physical theorizing. Both theoretical and experimental developments that generated great interest in Japan, and ultimately stimulated Kobayashi and Maskawa's 1973 work, went almost entirely unnoticed in the U.S. The episode exemplifies both the importance of untestable "themata" in developing new theories, and the difficulties that may arise when two parts of a research community work in relative isolation from one another.     

Simultaneous Measurement of Individual ATPase and Mechanical Reactions by a Single Myosin Molecule at Work

Based on techniques for single molecule imaging and nanomanipulation by optical tweezers, we have developed a new technique that allows simultaneous measurement of individual ATPase and mechanical reactions from a single myosin molecule during force generation. We show how the ATPase reaction couples to the mechanical reaction directly at the single molecule level. The results show that the myosin head can produce force even after releasing the bound nucleotide, probably ADP, suggesting that the chemical energy driven by ATP hydrolysis can be hysteretically stored in the myosin molecule. This view does not support a widely accepted hypothesis in which the force generation is tightly coupled to ligand dissociation.This paper was originally presented as an invited paper at the seventh Meeting on Near Field Optics, which was held on July 1, 1998 at Nagoya University, Nagoya, organized by the Research Group on Near Field Optics of the Optical Society of Japan, an affiliate of the Japan Society of Applied Physics.     

A twin optically-pumped far-infrared CH3OH laser for plasma diagnostics

A twin optically-pumped far-infrared CH₃OH laser has been constructed for use in plasma diagnostics. The antisymmetric doublet due to the Raman-type resonant two-photon transition is reproducibly observed at 118.8 m. With the 118.8-m line, it is obtained from the frequency separation of the anti-symmetric doublet that CH₃OH absorption line center is 16±1 MHz higher than the pump 9.7-m P(36) CO₂ laser line center. It is shown that the Raman-type resonant two-photon transition is useful in order to get several-MHz phase modulation for the far-infrared laser interferometer. Some preliminary performances of this twin laser for the modulated interferometer are described.This work was carried out under the collaborating research program at the Institute of Plasma Physics, Nagoya University, Nagoya 464, Japan.     

日本高等物理教育近况

本文介绍了日本高等物理教育的最新状况．文章首先回顾了日本近代物理教育的发展历程,然后介绍日本大学法人化以来高等物理教育方针的变化以及物理学科教学机构的决策方针的制定方法．根据作者在名古屋大学的学习与工作经验,文章概略地介绍了日本高校本科教育以及研究生的培养方式．主要包括本科生课程的设置、教学方法,研究生的课程的学习方式,课题的选择以及导师的指导方法等内容．希望本文可以为我国高等物理教育的教学改革与基础学科的人才培养提供借鉴．     

Analysis of Forbush decreases observed using a muon telescope in Antarctica starting on 21 June 2015

A cosmic-ray muon telescope has been collecting data since the end of 2014, which was shortly after the telescope was built in the Zhongshan Station of Antarctica. The telescope is the first observation device to be built by Chinese scientists in Antarctica. The pressure change is very strong in Zhongshan station. The count rate of the pressure correction results shows that the large variations in the count rate are likely caused by pressure fluctuations. During the period from 18 June to 22 June 2015, four halo coronal mass ejections(CMEs) were ejected from the Sun. These CMEs initiated a series of Forbush decreases(FD) when they reached the Earth. We conducted a comprehensive study of the intensity fluctuations of galactic cosmic rays recorded during FDs. The intensity fluctuations used in this study were collected by cosmic ray detectors of multiple stations(Zhongshan, McMurdo,South Polar, and Nagoya), and the solar wind measurements were collected by ACE and WIND. The profile of the FD of 22 June demonstrated a four-step decrease. The traditional one-or two-step FD classification method does not adequately explain the FD profile results. The interaction between the faster CME that occurred on 21 June 2015 and the two slow CMEs of the earlier few days should be considered. The cosmic ray intensities of the South Pole,McMurdo, and Zhongshan stations have similar hourly variations, whereas the galactic cosmic rays recorded between polar and non-polar locations are distinct. The FD pre-increase of 22 June 2015 for the Nagoya muon telescope(non-polar location) lags those of the McMurdo and Zhongshan stations(polar locations) by 1 h. The FD onset of22 June 2015 for the Nagoya muon telescope lags those of the polar locations by 1 h.     

Observation of Resonant Photon Tunneling in Photonic Double Barrier Structures

Reflectance and transmittance of 632.8 nm He-Ne laser light for photonic double barrier structures (consisting of a SF10 prism, SiO₂ layer, Al or Al₂O₃ active layer, SiO₂ layer and SF10 prism) were measured as a function of the angle of incidence for both the ρ- and s-polarized incidence. Sharp reflection dips and transmission peaks were observed at angles larger than the critical angle of total reflection. The appearance of the transmission peaks can be attributed to resonant photon tunneling through the photonic double barrier structures analogous to resonant electron tunneling through double potential barrier structures. Resonant tunneling is mediated by the long-range surface plasmon polariton in the case of the Al active layer and the electromagnetic guided modes in the case of the Al₂O₃ layer.This paper was originally presented at the seventh Meeting on Near Field Optics, which was held on July 1, 1998 at Nagoya University, Nagoya, organized by Research Group on Near Field Optics, the Optical Society of Japan, an affiliate of Japan Society of Applied Physics. The authors have won the Near Field Optics Award for their best presentation at the meeting.     

Study of Probe-Surface Interaction in Shear-Force Microscopy: Effects of Humidity and Lateral Spring Constant

The shear force between a glass probe and a mica surface has been investigated as a function of the relative humidity, H, and the lateral spring constant of the probe, K. It was found that the interaction length D_o decreases with increasing H and exhibits a sharp drop around H=40%. With increase in K from 5 to 40 N/m, D_o gradually increases, although this feature was absent when a probe with a softer tip-end was used. The latter result indicates that the shear force in an atmospheric condition is not a remote force but results from some contact between the tip and the surface. Our results that D_o is independent of the oscillating amplitude and that the resonance curve of the probe is almost symmetric except in close vicinity to the surface are not in accord with the force model proposed recently, i.e., the knocking mechanism. It is proposed that the probe can vibrate even if the probe touches the surface, and that the resonance frequency increases steeply as the contact tightens. Theoretical estimation of the contribution of noncontact forces is also described.This paper was originally presented at the seventh Meeting on Near Field Optics, which was held on July 1, 1998 at Nagoya University, Nagoya, organized by Research Group on Near Field Optics, the Optical Society of Japan, an affiliate of the Japan Society of Applied Physics.     

Calculation of reactor impedance for helicon discharge

We solve the Maxwell-Boltzmann equations and calculate reactor impedance for helicon device with the Nagoya type III antenna using a finite, width modeling of antenna current and inspect the dependence of various components of impedance on discharge parameters. The total resistance is divided into various components such as electron-ion contributions and axial-perpendicular field contributions. Moreover, the total resistance can be approximately expressed as the sum of TG and helicon contributions in a wide range of parameters     

A double pass rapid scanning Fourier transform spectrometer for plasma diagnostics

The construction and the performance of a double pass rapid scanning Fourier transform spectrometer are described. The instrument covers a frequency range below 900 GHz. It has a maximum spectral resolution of 6.6 GHz and a maximum time resolution of 10 msec. The spectrometer has been applied to JIPP T-II device at Institute of Plasma Physics in Nagoya University. Electron cyclotron emission from the device has been measured and the electron temperature of the plasma has been obtained. The results are shown.     

Studying semidiurnal variations in galactic cosmic rays

Seasonal changes in the semidiurnal variation of cosmic rays and their changes with the level of solar activity are discovered as a result of the long-term recording of cosmic rays by the spectrograph in Yakutsk (62°01′ N, 129°43′ E) and multidirectional muon telescope at Nagoya (35°10′ N, 136°58′ E). Seasonal changes are simulated using mechanisms proposed earlier by the authors.     

A 110 GHz SIS receiver for radio astronomy

A 110 GHz superconductor insulator superconductor (SIS) tunnel junction receiver has been developed and used in regular astronomical observations on the 4m radio telescope at the Department of Astrophysics, Nagoya University. The SIS junction consists of a sandwich structure of Nb/AlOx/Nb, and is cooled to 4.2K with a closed cycle He-gas refrigerator. The receiver exhibits a best double side band noise temperature of 23±2 K at 110GHz. Additional measurements at 98–115 GHz indicate that the receiver has a good response over this input frequency range.     

Effect of polymer tacticity on the molecular structure of polyelectrolyte/surfactant stoichiometric complexes in solutions and gels

The molecular structure of polystyrene sulphonate/CTAB stoichiometric complexes has been examined by means of small-angle neutron scattering in solutions and in the gel state for two different tacticities of the polystyrene moiety, namely atactic polystyrene and isotactic polystyrene. It is found that tacticity has no influence on the molecular structure in solution, while it plays a role in the gel state. The neutron scattering curves are interpreted with different helical models. The thermal properties of the gels are discussed in the light of the neutron scattering outcomes.Received: 7 April 2003, Published online: 5 August 2003PACS: 61.12.Ex Neutron scattering (including small-angle scattering) - 65.60. + a Thermal properties of amorphous solids and glasses: heat capacity, thermal expansion, etc. - 82.35.Rs Polyelectrolytes - 82.70.Gg Gels and solsB. Ray: Present address: Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.S. El Hasri: Permanent address: Département de Physique, Faculté des Sciences et Techniques du Guéliz, Université Cadi-Ayyad, B.P. 549, MA-40000 Marrakech, Morocco.The neutron scattering experiments reported in this paper have been carried out on V4, a small-angle camera located at BENSC-HMI Berlin (Germany).     

Comparison between old and new noise standards in Nagoya City

The Japanese Environmental Agency (now the Ministry of the Environment) updated the environmental quality standards for noise in April 1999. The new standards replaced the median value of percentile level L₅₀ for noise evaluation with the equivalent sound pressure level L_Aeq. The standards renewed the classification of areas and time sections. The most significant change was the introduction of category of artery-road-adjacent area.This report sets the range of the artery-road-adjacent area to 20 m or less from the applicable road to compare the new standards with the old, based on data collected in Nagoya City. The achieved rates for the new standards seem to be on the whole the same as those for the old standards. However, a detailed analysis reveals some differences, such as higher achieved rates in the artery-road-adjacent areas and lower achieved rates in the general areas for the new standards than for the old.     

Spectrum of long-term cosmic ray variations during the sunspot minimum in 2009

A method for determining the long-term spectrum of cosmic ray (CR) variations from observations with different ground-based (neutron monitors) and near-earth (stratosphere and satellite) detectors was presented in our previous works. In this paper, muon telescope data (Nagoya) are added, expanding the analyzed energy range and allowing us to determine the rigidity spectrum for 1974–2011. The data from the above devices for these years can be used jointly. The rigidity spectrum for the sunspot minimum of the 24th cycle was studied and compared with the CR intensity for the sunspot minima of other cycles. The reasons for abnormally high CR density during the minimum of the 24th cycle and other features of this period are discussed.     

On the Use of Space-Environmental Satellite Data for Global Magnetohydrodynamic Simulations

A global magnetohydrodynamic (MHD) model describes the solar-terrestrial system and the physical processes that live in it. Information obtained from satellites provides input to MHD model to compose a more realistic initial state for the equations and, therefore, more accurate simulations. However, the use of high resolution in time data can produce numerical instabilities that quickly interrupt the simulations. Moreover, satellite time series may have gaps which could be a problem in this context. In order to contribute to the overcoming of such challenges, we propose in this work a methodology based on a variant of the continuous wavelet transform to introduce environmental satellite data on the global resistive MHD model originally developed by Prof. Ogino at the University of Nagoya. Our methodology uses a simplified time-scale version of the original data that preserves the most important spectral features of the phenomena of interest. Then, we can do a long-term integration using this MHD model without any computational instability, while preserving the main time-scale features of the original data set and even overcome possible occurrence of gaps on the satellite data. This methodology also contributes to keeping more realistic physical results.     

A transmission line for plasma scattering measurements with a submillimeter wave gyrotron

A transmission system has been designed to produce a high intensity (100 W) and high quality (well-collimated and high purity) beam in the submillimeter wave range (f=354 GHz). Calculations using the Huygens equation for scalar diffraction show that this system can produce a high quality beam. The final goal is to apply it to scattering measurements of density fluctuations driven by instability and wave propagation during ion cyclotron resonance heating in the Compact Helical System (CHS) in the National Institute for Fusion Science at Nagoya. It will provide a high S/N ratio and high spatial and wave number resolution.     

Visualization of the human body toward the navigation diagnosis with the virtualized human body

In this article we present the visualization of the human body basing upon the X-ray CT and MR images. Topics and examaples of images rendered by the computer are all selected from the studies in the authors’ laboratory during about twenty years. Topics are classified into four groups. First we introduce a few historical pictures of cross section images, and the surface of bones and the skull. Second, the selected pictures in the surgical simulation system NUCSS (=Nagoya University Craniofacial Surgical Simulation system) we developed are shown. This system was for the simulation of the craniofacial surgery of the skull and the orthopedic surgery of the hip joint. This was the pioneering work which showed the potential of computer aid in surgery based upon 3D CT images about ten years in advance of the present rapid extention of the computer aided surgery. One of the earliest work to visualize the performance of the soft tissue — rendering of the cut skin is also included. Third, the virtualized endoscope system is presented in detail. The images of both the inside and the outside view of the bronchus, the vessel and the stomach are shown here with the introduction to the new concept of the navigation diagnosis. Finally the navigation through an Egyptian mummy is added.     

Millimeter-Wave Radiometer for the Measurement of Stratospheric ClO Using a Superconductive (SIS) Receiver Installed in the Southern Hemisphere

A new sensitive radiometer for atmospheric minor constituents has been developed by Nagoya University and the National Institute for Environmental Studies (NIES). The instrument equipped low-noise superconducting (SIS) mixer with a system noise temperature of 200K (SSB) at 204GHz. The SIS mixer is operated in a single side band mode with a side band ratio grater than 10dB by adjusting the two tunable backshorts of the mixer. Since any additional SSB filters are not necessary, we can simplify the quasi-optical system and reduce the standing waves which makes difficult to achieve a flat spectral baseline. We installed the observation system at Las Campanas Observatory, Chile in December 1999, and started the test observation from 2000 October. We have detected significant ClO emission at 204.3 GHz with an actual observation time of only 4 hours. This is the first detection of the ClO at 40km altitude from the mid-latitude region of the southern hemisphere. The Nagoya-NIES system has enabled continuous monitoring of ClO in the stratosphere with a time resolution of 4 or 5 hours.     

m=±1 and m=±2 mode helicon wave excitation

The characteristics of plasma produced by plane polarized m=±1 and m=±2 mode helicon waves were investigated for the first time. Plane polarized m=±1 and m=±2 mode helicon waves were mainly excited using a Nagoya type III antenna and a quadrupole antenna, respectively. Two-dimensional cross-field measurements of ArII optical emission induced by hot electrons were made to investigate the RF power deposition. The components of the wave magnetic field measured with a magnetic probe were compared with the field profiles computed for the m=±1 and m=±2 modes. Two and four high intensity plasma columns were observed for the m=±1 and m=±2modes, respectively. These columns were located at the regions between the antenna legs. The radial profiles of the wave magnetic field were in good agreement with computations     

Seven matched bolometers for millimeter wave observations

We have fabricated a millimeter wave observation system using an array of bolometric detectors. The performance of the system depends largely on obtaining identical performance from each bolometer. We achieved a variance in the responsivity of less than 4% except for one of the seven elements. The bolometers had an electrical NEP of 1.3×10^–16 W/Hz under radiation background loading of 30pW. We used an AC bridge readout circuit to significantly improve the stability of the array and showed that observations can be done without a mechanical beam switch. The bolometer array is now in use on the Nobeyama 45-m telescope for 150GHz observations.H. Matsuo thanks those who helped him work on bolometers during his stay in Berkeley, especially to T. Wilbanks, M. Devlin and C. Inman. The authors are also grateful to S. Sato and T. Watabe at Nagoya University for their advice on the AC bridge circuit. This work is partly supported by the Shimazdu Science Foundation.