橋本先生最終講義 (Final lecture by Dr Yukio Hashimoto), 2022.3.23

Dr Yukio Hashimoto, who will be retired at the end of March, gave his final lecture, “Looking back the traces of dreams”, in Center for Computational Sciences, University of Tsukuba on March 23rd, 2022. The lecture was held in hybrid meeting style (in person and online), participated in by his current and former collaborators.



橋本先生最終講義集合写真(Final lecture by Dr Hashimoto)
花束贈呈(Presenting a bouque)

プレスリリース, Press release

Dr Yabana and Collaborators have made a press release on ultra-fast optical response simulations of nano materials, using SALMON on Fugaku supercomputer. Details can be found in this page.


セミナー(Seminar) 2022.1.7: Dr Yoshiko Kanada-En’yo (Kyoto University)

Lecturer: Yoshiko Kanada-En’yo (Kyoto University)
Date/Time: Jan 7 (Fri), 13:45 pm
Title: Low-energy Gamow-Teller transitions in deformed N = Z odd-odd nuclei
Place: Meeting Room A (first floor), Center for Computational Sciences
Abstract: Low-energy Gamow-Teller transitions in deformed N = Z odd-odd nuclei (10B and 22Na) are studied by the beta-gamma AMD+GCM method with isospin projection. Roles of the pn correlation in GT transitions are discussed. Splitting of GT transition strengths occurs in 22Na because of the SU(4) symmetry breaking by the spin-orbit potential of the pn pair at the surface of 20Ne core.
Hiroyuki Morita and Yoshiko Kanada-En’yo, PHYSICAL REVIEW C 98, 034307 (2018)

准教授を公募(9/30締切) Opening of an Associate Professor position (Deadline: Sep.30)

Division of Nuclear Physics, Center for Computational Physics seeks to appoint an Associate Professor. Details can be found in this page. The deadline of the application is September 30th, 2021.


新メンバー:土田さん、吉永さん New members: Tsuchida and Yoshinaga

New graduate students in the Master course, Tsuchida and Yoshinaga have joined our group.


阿部さん、杉浦さん、修士取得。土田さん、学士取得(Abe-san and Sugiura-san got Msc degree, and Tsuchida-san got Bsc)

Mrs. Abe and Sugiura have been awarded degrees of the Master of Science. Mr Tsuchida has been awarded the Bachelor degree on March 25th, 2021.


ハイライト論文に選定 A paper selected as Editors’ Suggestion

A paper by N. Hinohara and T. Nakatsukasa collaborating with K. Washiyama (Kyushu Univ.) has been published in Physical Review C of American Physical Society, and selected as an Editors’ Suggestion. The paper proposes a new computational method for the collective inertial masses in spontaneous fission dynamics.

日野原さん・中務さんが九州大学の鷲山さんとの共同研究として提案した、自発核分裂における集団慣性質量の新しい計算手法に関する論文が、アメリカ物理学会のPhysical Review Cに出版され、Editors’ Suggestionに選ばれました。

集中講義 (Lectures) 2021.1.13-15:日高義将氏、HIDAKA, Yoshimasa(KEK)

A series of lectures will be delivered by Dr Hidaka (KEK) on “QCD matter at Extreme Conditions”, at Meeting Room A, CCS, University of Tsukuba, in January 13-15, 2021. The lecture is given in Japanese.

日程:2021年1月13日 10:30-16:45、1月14日 10:30-16:45、1月15日 13:30-16:45
場所:筑波大学計算科学研究センター 会議室A
内容: 宇宙初期や高密度天体の内部などに現れる超高温,超高密度,超磁場中といった極限状態におけるハドロン(QCD)の物性について講義する.このような極限状態のQCDの性質を理解するための解析手法について基本的な事柄を紹介し,それがどのようにQCDへ応用され,どのような理解に至っているか解説する.また,最近の物性物理で発展しているトポロジーを用いた量子相のアプローチのQCDへの応用についても紹介する.

セミナー(Seminar) 2020.12.11: Dr Cheng-Jun Xia (Zhejiang University, China)

Lecturer: Cheng-Jun Xia (Zhejiang University)
Date/Time: 15:30, December 11 (Fri), 2020
Place: Meeting Room A in Center for Computational Sciences, together with Zoom.
Title: Nuclear pasta structures and symmetry energy
Abstract: In the framework of the relativistic mean field model with Thomas-Fermi approximation, we study the structures of low density nuclear matter in a three-dimensional geometry with reflection symmetry. The numerical accuracy and efficiency are improved by expanding the mean fields according to fast cosine transformation and considering only one octant of the unit cell. The effect of finite cell size is treated carefully by searching for the optimum cell size. Typical pasta structures (droplet, rod, slab, tube, and bubble) arranged in various crystalline configurations are obtained for both fixed proton fractions and β-equilibration. It is found that the properties of droplets/bubbles are similar in body-centered cubic (BCC) and face-centered cubic (FCC) lattices, where the FCC lattice generally becomes more stable than BCC lattice as density increases. For the rod/tube phases, the honeycomb lattice is always more stable than the simple one. By introducing an ω-ρ cross coupling term, we further examine the pasta structures with a smaller slope of symmetry energy L = 41.34 MeV, which predicts larger onset densities for core-crust transition and non-spherical nuclei. Such a variation due to the reduction of L is expected to have impacts on various properties in neutron stars, supernova dynamics, and binary neutron star mergers.

This seminar is given in English. Contact the organizer (Kai Wen) to obtain the Zoom link.

セミナー(Seminar) 2020.11.20: Dr Simin Wang (MSU, USA)

Lecturer: Simin WANG (MSU)
Date/Time: 14:00, November 20 (Fri), 2020
Place: Meeting Room A in Center for Computational Sciences, together with Zoom.
Title: Study of the two-proton radioactivity
Abstract: Two-proton (2p) radioactivity is a rare decay mode found in a few very proton-rich isotopes. The 2p decay width and properties of emitted protons carry invaluable information on nuclear structure in the presence of a low-lying proton continuum. For example, in mid-heavy nuclei, the measured 2p decay of 67Kr turned out to be unexpectedly fast [1]. And more recently, as the mirror of the halo nucleus 11Li, 11O was observed for the first time with a very broad peak [2]. To understand these exotic phenomena, we apply the Gamow coupled-channel method, which describes structure and decays of three-body systems within one coherent theoretical framework by utilizing resonant and scattering states in eigenfunction expansion [3]. The calculated lifetimes, angular correlations, and other properties indicate that the nuclear inner structure and continuum effect play a significant role in the decay process [2,3]. Moreover, to provide insights into the impact of nucleonic superfluidity on two-nucleon decay processes, we are developing a novel time-dependent approach, which will allow us to consider different experimental initial-setups and directly compare the predictions and data without losing structural information. With this new approach, we reveal the different dynamics of 2p and 2n decays.
[1] Goigoux et al., Phys. Rev. Lett. 117, 162501 (2016).
[2] T.B. Webb et al., Phys. Rev. Lett. 122, 122501 (2019).
[3] S. M. Wang and W. Nazarewicz, Phys. Rev. Lett. 120, 212502 (2018).

This seminar is given in English. Contact the organizer (Kai Wen) to obtain the Zoom link.