Nambu-Jona-Lasinio Model Coupled to Constant Electromagnetic Fields in D-Dimension

Critical dynamics of the Nambu-Jona-Lasinio model, coupled to a constant electromagnetic field in D=2, 3, and 4, is reconsidered from a viewpoint of infrared behavior and vacuum instability. The latter is associated with constant electric fields and cannot be avoidable in the nonperturbative framework obtained through the proper time method. As for magnetic fields, an infrared cut-off is essential to investigate the critical phenomena. The result reconfirms the fact that the critical coupling in D=3 and 4 goes to zero even under an infinitesimal magnetic field. There also shows that a non-vanishing $F_{\mu\nu}\widetilde F^{\mu\nu}$ causes instability. A perturbation with respect to external fields is adopted to investigate critical quantities, but the resultant asymptotic expansion excellently matches with the exact value.Comment: 27 pages, 17 figure files, LaTe

Motion Generation during Vocalized Emotional Expressions and Evaluation in Android Robots

Vocalized emotional expressions such as laughter and surprise often occur in natural dialogue interactions and are important factors to be considered in order to achieve smooth robot-mediated communication. Miscommunication may be caused if there is a mismatch between audio and visual modalities, especially in android robots, which have a highly humanlike appearance. In this chapter, motion generation methods are introduced for laughter and vocalized surprise events, based on analysis results of human behaviors during dialogue interactions. The effectiveness of controlling different modalities of the face, head, and upper body (eyebrow raising, eyelid widening/narrowing, lip corner/cheek raising, eye blinking, head motion, and torso motion control) and different motion control levels are evaluated using an android robot. Subjective experiments indicate the importance of each modality in the perception of motion naturalness (humanlikeness) and the degree of emotional expression

Prevalence of human papillomavirus, Chlamydia trachomatis, and Neisseria gonorrhoeae in commercial sex workers in Japan.

OBJECTIVE: We used the hybrid capture assays to investigate the prevalence of human papillomavirus (HPV), Chlamydia trachomatis and Neisseria gonorrhoeae among commercial sex workers in Tokyo. METHODS: Five hundred forty-six consecutive commercial sex workers (CSW) who visited an STD clinic for STD checkup in 1998 and 1999 were studied. A control group consisted of 233 consecutive women who visited a general gynecological clinic for annual checkup. A cervical sample was obtained for hybrid capture assays for HPV-A (low-oncogenic-risk types), HPV-B (intermediate- and high-oncogenic-risk types), C. trachomatis, and N. gonorrhoeae. Fisher's exact test was used for statistical analyses. RESULTS: The positive rate for HPV-B among the CSW was 48.4%, significantly higher than the 6.0% among the control subjects. The positive rates for HPV-A, C. trachomatis, and N. gonorrhoeae were also significantly higher among the CSW than among the control subjects. Among the microorganisms tested, the positive rate for HPV-B was the highest in both the STD and control groups. CONCLUSIONS: The high prevalence of HPV, C. trachomatis, and N. gonorrhoeae infection in CSW poses a risk of further transmission of STD to the general public, suggesting the need for further education and screening for CSW and the general public. We found high- and intermediate-oncogenic-type HPV to be the most prevalent infection among both CSW and control subjects. Screening for HPV may be necessary in STD and general clinics to predict the risk of cervical malignancy. Hybrid capture assays, which permit simultaneous detection of HPV and other STD with high sensitivity, may be a useful diagnostic method

Status of ECR ion sources at JAERI

At the Takasaki site of Japan Atomic Energy Research Institute, four ECR ion sources were purchased or developed so far. This paper will report their performance, modification and status. The outlines for each source are as follows; 1. OCTOPUS purchased from IBA s.a. has been in use with a cyclotron since 1990. The gas feed system was modified to change gas species within 10 minutes to avoid impurity ions in the cocktail beam acceleration technique of the cyclotron. 2. ECR-18 with 18-GHz microwave has a solenoid coil between a pair of mirror coils to change mirror ratio in a wide range. A bump between mirror peaks in the original axial field distribution was removed by halving the solenoid length. The performance in generating high charge state ions was significantly improved as a result. 3. HYPERNANOGAN was purchased from PANTECHNIK s.a. and installed in the cyclotron system this year. Test operation was successfully made with generation of Ar, Pb and Ta ions. 4. MINI ECR is a full permanent magnet source with 10 GHz microwave. As a result of modifications for vacuum and the application of a bias probe, 40 microA of Ar4+ beam was obtained, for example. Using this source, a new technique was developed to vaporize very refractory materials into plasma by fluorinating them with SF6 plasma. The source is in use for a 400 kV ion implantor since last year

Optimum Arrangement of Resonator in Micro-bunch Free Electron Laser(III. Accelerator, Synchrotron Radiation, and Instrumentation)

Using a short-bunched beam of electrons from a linear accelator, the output of the micro-bunch FEL has been studied experimentally to clarify the optimum arrangement of an open resonator on the electron orbit. The output depends sharply on the arrangement, and the maximum output is observed when the resonator axis intersects the electron orbit with the angle of 3°

Exotic radiation from a photonic crystal excited by an ultra-relativistic electron beam

We report the observation of an exotic radiation (unconventional Smith-Purcell radiation) from a one-dimensional photonic crystal. The physical origin of the exotic radiation is direct excitation of the photonic bands by an ultra-relativistic electron beam. The spectrum of the exotic radiation follows photonic bands of a certain parity, in striking contrast to the conventional Smith-Purcell radiation, which shows solely a linear dispersion. Key ingredients for the observation are the facts that the electron beam is in an ultra-relativistic region and that the photonic crystal is finite. The origin of the radiation was identified by comparison of experimental and theoretical results.Comment: 4 pages, 5 figure