Seminars

2008

GCOE seminar
title
Crystalline ion beams and the ordered state of ions
author
Professor Alexander Smirnov(Joint Institute for Nuclear Research, Dubna, Russia)
date
Feb. 10 (Tue), 2009, 10:30-12:30
place
The Meeting Room [2F], Accelerator Building, Institute for Chemical Research, Kyoto University
abstract
The idea of crystalline beam has a large interest now. The achievement of the very low temperature in the beam rest frame gives new possibilities in the accelerator physics. The ordered state of circulating ion beams was observed on a few storage rings in the world. The ordered state of the proton beam was observed at S-LSR storage ring (Kyoto University). Theoretical and numerical investigations were done for the formulation of necessary conditions for the achievement of the ordered state. Up to now the 2D and 3D crystalline beams were not observed in real storage rings. One of the research subjects of S-LSR is a test bench to produce crystalline beams of Mg ions under the action of the laser cooling. The S-LSR lattice structure was especially elaborated for the formation of 3D crystalline beams.
contact
Akira Noda, noda@kyticr.kuicr.kyoto-u.ac.jp, ext. 17(Uji)3281
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GCOE/YITP seminar
title
Variational calculation of the K-pp system with chiral dynamics
author
Akinobu Doté (IPNS, KEK)
date
Jan. 28 (Wed), 2009, 16:00-
place
Conference Room K206, Yukawa Institute, Kyoto University
abstract
Kaonic nuclei (nuclear systems with a strongly bound anti-kaon) have recently become a hot topic in hadron and nuclear physics when it was suggested, using a simple phenomenological KbarN potential model [1], that they might exist as deeply bound states with small width. However, experiments performed in search for such states [2] have so far been inconclusive. An important prototype system for such investigations is K-pp, the simplest Kbar-nuclear cluster. Recently this system has been studied using Faddeev [3] and variational [4] approaches with KbarN interactions constrained by phenomenology and properties of the Λ(1405).
In this seminar, first, some brief introduction on kaonic nuclei will be given. Then, we present an improved variational calculation [5] of the K-pp system with realistic interactions as input:
・the Argonne v18 potential with its strongly repulsive short-range core as a realistic NN potential reproducing NN scattering and deuteron data;
・an updated effective KbarN interaction based on chiral SU(3) coupled-channel dynamics [6] which reproduces scattering data in the S=-1 meson-baryon sector and dynamically generates the Λ(1405) as an I=0 KbarN quasibound state embedded in the resonant πΣ continuum. This interaction is translated into the form of an equivalent single-channel, complex and energy dependent KbarN potential.
In addition, we will show other effects not included in the above calculation: 1. dispersive correction, 2. p-wave KbarN interaction, and 3. two-nucleon absorption. Taking all of these effects into account, the K-pp system turns out to be shallowly bound with large decay width: B(K-pp) = 20 - 40 MeV and Γ_total = 55 - 120 MeV.
Our calculation shows that the K-pp system is rather weakly bound, comparing to the previous calculations [3,4]. I'll explain the reasons of such a difference between our results and previous ones. If I have a time, I'd like to give some comments and discuss on the very recent experimental result [7] which seems to indicate the existence of deeply bound K-pp system.
The contents of this seminar are summarized in the latest our paper [8].
[1] Y. Akaishi and T. Yamazaki, Phys. Rev. C65, 044005 (2002).
[2] T. Suzuki et al., PL B 597, 263 (2004); M. Agnello et al., PRL 94, 211303 (2005).
[3] N. V. Shevchenko, A. Gal, and J. Mares, Phys. Rev. Lett. 98, 082301 (2007).
Y. Ikeda and T. Sato, Phys. Rev. C76, 035203 (2007).
[4] T. Yamazaki and Y. Akaishi, Phys. Rev. C76, 045201 (2007).
[5] A. Dote, T. Hyodo and W. Weise, Nucl. Phys. A804, 197 (2008).
[6] T. Hyodo and W. Weise, Phys. Rev. C77, 035204 (2008).
[7] T. Yamazaki et al., arXiv:0810.5182 [nucl-ex], proceedings of EXA'08.
[8] A. Dote, T. Hyodo and W. Weise, Phys. Rev. C79, 014003 (2009).
contact
Yoshiko Enyo ext.7029
note
URL: http://www.yukawa.kyoto-u.ac.jp/contents/seminar/detail.php?SNUM=50724

 

Glonal COE seminar
title
Enzyme Mediated Membrane Restructuring: An Interplay Between PLA2 Activity And Membrane Organization
author
Assistant Professor Chad Leidy (Department of Physics, Universidad de los Andes, Bogota, Colombia)
date
Jan. 21 (Wed), 2008, 16:00 -
place
The 4th Lecture Hall [5F / Room525], Physics Department, Kyoto University
abstract
The hydrolytic activity of phospholipase A2 is only triggered at the interface between water and the membrane surface. This hydrolytic process involves the breakdown of phospholipids to produce free fatty acids and lysolipids. PLA2 hydrolysis generates a steady modification of lipid composition that strongly influences membrane structure and organization. For this reason, this enzyme is considered to act as a membrane-restructuring agent. In addition, several physical aspects of the membrane, such as domain formation and lipid phase behavior, may increase enzyme activity by reducing the level of lipid packing, making the physical state of the membrane the main regulator of enzyme activity. The interplay between the physical properties of the membrane and PLA2 activity results in several interesting traits such as directed membrane restructuring, triggering and inhibition of enzyme activity, and enzyme mediated modulation of membrane rigidity. We explore several of these aspects in model and cell membranes and relate the findings to physiologically relevant processes such as bacterial resistance to antimicrobial activity and platelet clotting.
contact
Kenichi Yoshikawa,
yoshikaw@scphys.kyoto-u.ac.jp, ext.3812
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Global COE seminar
title
Knowledge of Knowledge: Widely Interdisciplinary Research
author
Professor Piet Hut (Institute for Advanced Study, Princeton, USA)
date
Jan. 15 (Thu), 2009, 16:00-18:00
place
Yukawa Memorial Hall, Panasonic Auditorium
abstract
Many of the most interesting problems in current scientific research require interdisciplinary collaborations, spanning a large number of disciplines. From cognitive science and systems biology to environmental studies and challenges like critical evaluations of alternative medicine, we need teams of specialists to talk and work together. However, differences in culture and methodology provide significant barriers for broadly interdisciplinary collaborations. Each discipline has its own approach to knowledge, but because this knowledge is shared within the discipline, most researchers are not aware of the hidden assumptions involved. It is a kind of tacit knowledge, something you learn as a student, without any specific discussion or critical analysis. What is needed for broadly interdisciplinary studies is not only an increase in knowlege, but rather a focus on knowlege of knowledge. What do we know about the limits of how we know? This is the central question that will be addressed in this lecture.
contact
Shin Mineshige, shm@kusastro.kyoto-u.ac.jp, ext.3901
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Global COE seminar
title
Low Energy Constants of the Chiral Perturbation Theory from the QCD instanton vacuum model
author
Mirzayusuf Musakhanov (Uzbekistan National University)
date
Jan. 14th (Wed), 2009 16:00pm-
place
Room Y206, Yukawa memorial hall, Yukawa Institute for Theoretical Physics
abstract
In the framework of the instanton vacuum model it was derived the partition function for the light quarks. We make expansion over the current mass $m$ and number of colors $N_c$ and evaluate ${\cal O}(1/N_c, m, m/N_c, m/N_c\,\ln m)$ -corrections to the dynamical quark mass $M$, the quark condensate $\langle\bar{q}q\rangle$, the pion mass $M_\pi$ and decay constant $F_\pi$. There are several sources of these corrections: meson loops, finite size of the instanton distribution and the quark-quark "tensor" interaction terms. In contrast to the expectations, we found that numerically the $1/N_c$-corrections to dynamical mass are large and mostly come from meson loops. As a consequence, we have large $1/N_c$-corrections to all the other quantities. To provide the values of $F_\pi(m=0), \langle\bar{q}q(m=0)\rangle$ in agreement with ChPT, we offer a new set of parameters - average instanton size $\rho$ and average inter-instanton distance $R$. Finally, we find the ChPT SU(2)$_f$ low-energy constants $\bar{l}_3, \bar{l}_4$ in a good correspondence with the phenomenology and lattice results.
contact
Akira Ohnishi (ext. 7012), YITP
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GCOE・YITP Lecture Series (Astrophysics Lecture)
title
Thermal inflation, gravitational waves, baryogenesis and dark matter: a theory for a quarter of the history of the universe
author
Professor Ewan D. Stewart (KAIST, Korea)
date
Dec. 22 (Mon), 2008, 10:30−12:00, 13:30−15:00
Dec. 24 (Wed), 2008, 10:30−12:00
Jan. 6 (Tue), 2009, 10:30−12:00
place
Conference Room K206, Yukawa Institute, Kyoto University
abstract
I show how the simple extension of the Minimal Supersymmetric Standard Model $W = \lambda_u Q H_u \bar{u} + \lambda_d Q H_d \bar{d} + \lambda_e LH_d\bar{e}+\frac{1}{2} \lambda_\nu \left( L H_u \right)^2 + \lambda_\mu \phi^2 H_u H_d + \lambda_\chi \phi \chi \bar\chi$ gives rise to neutrino masses, the MSSM $\mu$-term, an axion solving the strong CP problem, thermal inflation solving the moduli and gravitino problems, a gravitational wave background potentially observable by DECIGO, baryogenesis, and dark matter.
contact
Takahiro Tanaka, ext.7018, tanaka@yukawa.kyoto-u.ac.jp
note
Schedule:
Dec.22 10:30-: seminar briefly covering everything.
13:30-: informal lecture on thermal inflation and gravitational waves.
Dec.24 10:30-: informal lecture on thermal inflation, baryogenesis and dark matter.
Jan. 6 10:30-: informal lecture on numerical simulations of thermal inflation baryogenesis.

 

Global COE seminar
title
Lecture on Non-LTE Radiative Transfer (Basics)
author
Professor Kim Kap-Sung
(Kyung Hee University, Korea)
date
Dec. 5 (FRI), 2008, 15:00-16:00, 16:10-17:10
Dec. 12 (FRI), 2008, 15:00-16:00, 16:10-17:10
Dec. 19 (FRI), 2008, 15:00-16:00, 16:10-17:10
place
5F Meeting room, Astrophysics Department, [Bldg.4]
abstract
This lecture on the radiative transfer problem of solar atmosphere has following contents; 1) The Radiation Field, 2) Radiation Transfer, 3) Emission and Absorption, 4) The Non LTE Rate Equation, 5) Numerical Method for Non LTE Radiation Transfer, 6) Summary Numerical methods and software techniques applied in solar study are demonstrated through computer practices using the C++ language. Following problems are solved in the practices; a) Statistical equilibrium of model atoms, such as H, Ca, Na and etc. b) Radiation transfer in model atmospheres.
contact
Kiyoshi Ichimoto, (ichimoto@kwasan.kyoto-u.ac.jp, 0578-86-2311)
Yuki Hashimoto, (hasimoto@kwasan.kyoto-u.ac.jp, ext 3906)
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Global COE seminar
title
Polymer systems with oscillating mechanical behavior
author
Professor Valentina Vasilevskaya
(Nesmeyanov Institute of Organoelement Compounds Russian Academy of Sciences)
date
Dec. 3rd (Wed), 2008, (10:30-12:00)
place
The 4th Lecture Hall[Room525 5F], Physics Department
abstract
The significance of stimulus-responsive gels is their ability to undergo volume phase transition, which was first theoretically predicted by Dusek and Patterson. Thereafter, in 1979, Tanaka first experimentally observed for slightly cross-linked poly(acrylamide) (PAM) gels swollen in water-acetone mixtures. Since then, volume phase transitions in gels have been observed for a great number of polymer gels based on networks with different chemical structures. The wide spectrum of interactions in polymer gels gives rise to boundless opportunities for the design of gels with specific properties. Currently, stimulus-responsive hydrogels are becoming increasingly attractive for the use in various branches of biotechnology and medicine. In the presentation, Prof. Vasilevskaya will discuss not only polymer gels but also other experiments of volume phase transition and its theories, together with her precise experiences.
contact
Kenichi Yoshikawa, Department of Physics, Kyoto University
Room 230, Bld 5, North Campus, (075-753-3812, ext. 3812)
yoshikaw@scphys.kyoto-u.ac.jp
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Global COE seminar
title
Blackfolds
author
Professor Roberto Emparan (Universitat de Barcelona)
date
Nov. 25 (Tue), 2008, 13:30 - 15:00)
place
K206[research building 2F], YITP
abstract
The dynamics of black holes in higher dimensions is turning out to be much richer than in four dimensions, and new tools are required in order to analyze them. An important new feature of higher-dimensional black holes is that their horizons can have two characteristic lengths of very different size. I will describe an approach that captures their dynamics at scales much larger than the short scale. This approach reveals several new kinds of black holes.
contact
Takahiro Tanaka (tanaka@yukawa.kyoto-u.ac.jp)
Tetsuya Shiromizu (shiromizu@tap.scphys.kyoto-u.ac.jp)
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Special lecture at the Physics Department of Kyoto University
title
Complex Networks: From the WWW to the cell
author
Professor Laszlo Barabasi
(Center for Complex Network Research, Northeastern University and Department of Medicine, Harvard University, USA)
date
Nov. 17th (Tues.) 10:00-11:30
place
Inamori Lecture hall in the main building of Shiran-Kaikan
abstract
Systems as diverse as the world wide web, Internet or the cell are described by highly interconnected networks with amazingly complex topology. Recent studies indicate that these complex networks are the result of self-organizing processes governed by simple but generic laws, resulting in architectural features that appear to be universal. My goal is to discuss the amazing order characterizing our interconnected work, and their implications to network behavior and robustness.
contact
Sigeru Shinomoto, Nonlinear Dynamics Group, Department of Physics, Kyoto University (ext. 3778)
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Yukawa Institute, Kyoto GCOE ASTROPHYSICS SEMINAR
title
Shaping globular clusters
author
Douglas Heggie (University of Edinburgh, UK)
date
3:00 pm- , November 6, Thursday, 2008
place
K206, Yukawa Institute for Theoretical Physics, Kyoto University
abstract
Globular star clusters have a wide range of surface brightness profiles, ranging from classic King-type profiles all the way to highly concentrated profiles with a vanishing core radius. In this seminar I discuss the various mechanisms which could account for this variety, including the behaviour of intermediate-mass black holes, blackhole binaries, neutron star binaries, and mere accidents of birth and upbringing. I focus on two particularly well studied examples: M4 and NGC 6397.
contact
Shigehiro Nagataki, ext.7019
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Global COE Seminar
title
Astronomy in Virtual Worlds: from meetings to collaborations to simulations
author
Professor Piet Hut(Institute for Advance Study, Princeton)
date
Date and Time: Sep. 25 (THU), 2008, 14:00 - 15:00)
place
(K206[2F], Yukawa Institute for Theoretical Physics, Kyoto University
abstract
A group of astronomers has established a virtual astronomy institute in Second Life, a 3D on-line virtual world where astronomers worldwide can meet -- all you need is a laptop and an internet connection. The institute is called the Meta Institute for Computational Astrophysics, MICA for short (http://www.mica-vw.org/). We are using MICA for lectures and workshops, and most recently also for visualizing simulations, by reprogramming the physics engines of some virtual worlds, like OpenSim.
contact
Shin Mineshige, shm@kusastro.kyoto-u.ac.jp, ext.3901
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GCOE/Yukawa Institute Colloquium
title
Successful Letters in Physical Review Letters: An editor's perspective
author
Manolis Antonoyiannakis (American Physical Society)
date
4:00 p.m. Steptember 25, Thursday, 2008
place
Panasonic Auditorium, Yukawa Hall, YITP, Kyoto University
abstract
A successful scientific paper relies critically on (a) the quality of the "raw" material provided by the authors, (b) the referees, and (c) the editorial decisions guiding the review process. Clearly, these three factors are interrelated, and authors can actually in°uence items (b) and (c) by attending to (a), as well as by adhering to some simple rules of common sense, on which I will elaborate in this talk. I will also provide some history from the  ̄rst 50 years of PRL, with emphasis on lessons from the past that are of relevance today, and on the current and future developments in the journal and in the American Physical Society (APS).
Some pertinent questions:
- How can authors contribute towards a timely and (hopefully) accurate review process of their papers?
- How are referees chosen, and what is expected of them? Referee statistics patterns. APS Outstanding
Referees.
- What are the challenges an editor faces? What are the operating constraints?
- Why and when it makes sense for an editor to reject a manuscript without external review.
- Are there cultural, ethnic, geographical, or other types of bias in the review process? Can we tell?
- Life after publication: New material and services by APS to highlight the very best papers.
- Can we measure the full impact of a journal? How? Can we rank journals based on such a metric?
- Does it make sense for authors to decide which journal to submit their best work to by comparing journal impact factors?
- Raising the bar: Should PRL publish fewer papers?
contact
 
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Yukawa Institute, Kyoto GCOE・ ASTROPHYSICS SEMINAR
title
Liquid Inspection with Reflection Terahertz Time Domain Spectroscopy
author
Uffe Moller (Technical University of Denmark)
date
Date and Time: Sep. 11 (THU), 2008, 14:00 - 15:00  
place
Place : Room 413 , Faculty of Science Building 5, Fourth Floor
abstract
The terahertz region bridges the gap in the electromagnetic spectrum covering the frequency range between radio waves and infrared light and it. This spectral range, broadly defined as 0.1-10 THz, gives, for one thing, information about intermolecular interactions, e.g. hydrogen bonds to surrounding molecules. Since its breakthrough about 20 years ago, THz Time Domain Spectroscopy (THz-TDS) has found many applications in a wide range of fields such as fundamental physics, chemistry and biology as well as more practical applications including the fields of pharmaceutics and security.
In this talk , I will give a brief introduction to THz-TDS. I will illustrate how Reflection THz-TDS can be used for inspection of liquids in commercial plastic and glass bottles. I will demonstrate that it is possible to determine the alcohol content of a liquid, and that liquids can be classified as either harmless or inflammable. The method operates in reflection mode with the result that liquids opaque to THz radiation can be characterized with little influence of the bottle shape. The method works with plastic bottles as well as glass bottles, with absorption of THz radiation by the plastic or the glass being the limiting factor. The reflection mode allows for automatic control of the validity of the measurement. The method will be useful in liquid scanning systems at security checkpoints.
contact
Kouichiro Tanaka, ext,3756
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