vol. 74 | iTHES

Vol. 74, March 30th, 2015


  • Announcement
  • Upcoming Events
  • Event report
  • Paper of the week

Paper of the week

Kouhei Washiyama


"Microscopic analysis of fusion hindrance in heavy systems"

From the Office

The office of iTHES assistant, Ms.Chikako Oota is situated at the second floor of the main research building, room # 246. The extension number is 3261. She will be at the office from 10 a.m. to 16 p.m.


Takuya Kanazawa (research scientist in ithes-phys team) received the "9th Particle Physics Medal: Young Scientist Award in Theoretical Particle Physics". He was awarded for his work entitled "Adjoint QCD on R^3 x S^1 with twisted fermionic boundary conditions" JHEP 1406 (2014) 181, which was written with Dr. T. Misumi (Keio Univ.). The citation of the prize addressed the expectation for future developments that their work would initiate in various subjects, such as the lattice QCD simulations, quark confinement mechanism, super symmetric gauge theories, and the theory with extra dimensions. In his acceptance speech at the Japanese Physical Society Meeting on March 23, 2015, he thanked? Tetsuo Hatsuda (iTHES group leader and ithes-phys team leader) as well as colleagues at ithes-phys team for their support and fruitful discussions.

Akira Furusaki (ithes-cond team) and Tetsuo Hatsuda (ithes-phys team) are featured in the RIKEN video-library, "From high-school science to the forefront researches":
* Superfluidity and superconductivity:
* Neutron star and superconductivity:
* Topological superconductor:

Also, some of the ithes members appeared in the RIKEN promotion video
03:10-03:40 T. Hatsuda (ithes-phys) and T. Tamagawa (ithes-phys)
04:10-04:30 T. Hatsuda (ithes-phys)
09:08-09:18 Y. Sugita (ithes-bio and ithes-mcc)
11:48-12:00 S. Nagataki (ithes-mcc)
12:38-12:58 E. Hiyama (ithes-phys)
13:20-13:24 T. Hatsuda (ithes-phys)


Upcoming Events

iTHES international workshop
April 7 - 10, 2015
iTHES-NCBS 2nd Joint Meeting on "Theoretical Biology"
web page: http://ncbs-theobio2.riken.jp/
venue: 2nd floor of the main cafeteria ( http://ncbs-theobio2.riken.jp/access/ )
Contact: A. Mochizuki, ithes-bio team (mochi@riken.jp)
Sponsors: RIKEN iTHES and Simons Centre at NCBS (http://theory.ncbs.res.in/)

iTHES Colloquium
April 8, 2015, 16:00 -
Prof. Madan Rao (Simons Centre, NCBS)
"Active Composite Cell Surface : Implications to molecular organization, shape and information processing"
web page: http://ncbs-theobio2.riken.jp/Organizers:
place: 2nd floor of the main cafeteria ( http://ncbs-theobio2.riken.jp/access/ )

Event report

Three-day tutorial school on the physics of quark gluon plasma and relativistic heavy ion collisions was held in Okochi Hall (March 25-27, 2015) under the support of iTHES.
More than 100 graduate students and young posdocs from all over Japan have attended the school.
This was a good start towards the International? Quark Matter Conference to be held in Kobe, Sep.27-Oct.3, 2015: http://qm2015.riken.jp/

Paper of the week

Kouhei Washiyama
"Microscopic analysis of fusion hindrance in heavy systems"
In fusion reactions of heavy atomic nuclei, such as synthesis of superheavy elements, it is known that the fusion probability is strongly hindered compared with that in light- and medium-mass systems, called fusion hindrance. In this paper, we analyze the origin of the fusion hindrance by a microscopic time-dependent Hartree-Fock (TDHF) theory. We extract nucleus-nucleus potential and energy dissipation in heavy systems directly from TDHF simulations of central collisions of two heavy nuclei. The extracted potentials show a dynamical increase at short relative distances where two nuclei are largely overlapped. This is due to large Coulomb force, which induces the disappearance of an ordinary Coulomb barrier in the potential. Our further analysis shows that this dynamical increase of potential plays a more important role than energy dissipation for understanding the origin of the fusion hindrance. I hope that the present analysis will help for experimentalists to design new experiments of the synthesis of superheavy elements, and that new elements named by Japanese researchers will appear in the periodic table, someday. Finally, I really appreciate the comments raised during my short talk at the coffee meeting last month.