斎藤さん修士（理学）、八百板さん修士（理学）
2018年3月24日 | 新着情報
斎藤さんと八百板さんが修士（理学）の学位を取得しました。
関澤さん新潟大・助教（テニュアトラック）に着任
2018年1月9日 | 新着情報
当研究室の出身で2015年3月に博士（理学）の学位を取得した関澤一之さんが、2018年1月から新潟大学の特任助教（テニュアトラック）に着任しました。関澤さんは、筑波大学で学位を取得後、ポーランド・ワルシャワ工科大学やアメリカ・ワシントン大学でポスドク研究員として原子核理論の研究を行なってきています。
つくば不安定核セミナー開催（2018.1.17)
| 新着情報
第40回つくば不安定核セミナーを2018年1月17日に筑波大学計算科学研究センターにおいて開催いたします。今回は、KEK理論センターの久徳浩太郎氏を講師にお迎えして、2017年に観測された中性子星合体の重力波観測について話して頂きます。
また、セミナーに先立ち、13:00-14:00, 14:30-15:30の予定で、同じ場所で、重力波天文学について非専門家向けの講義をして頂きます。
Lecturer: Koutarou Kyutoku (KEK)
Date/Time: January 17th (Wed), 2018, 16:00-
Place: Conference Room B (1F), Center for Computational Sciences, University of Tsukuba
Title: GW170917
Abstract: The last year has witnessed a spectacular opening of multimessenger astronomy with binary neutron star mergers. Gravitational waves from the binary neutron star merger, GW170817, are detected by the LIGO-Virgo collaboration. They informed us that neutron stars should be moderately compact (say, smaller than 13-14km). A nominal short gamma-ray burst, GRB170817A, were detected by Fermi and INTEGRAL satellites at 2sec after merger. This detection confirmed that binary-neutron-star mergers can drive a kind of short gamma-ray bursts, although this event was not a typical gamma-ray burst involving an ultrarelativistic jet. An ultraviolet/optical/infrared transient, AT 2017gfo, is observed by a follow-up campaign by many telescopes. This transient was not similar to any other transients those have been discovered and is largely consistent with a predicted marcronova/kilonova, quasithermal radiation powered by the decay of r-process elements synthesized in the material ejected during binary neutron star mergers. Thus, binary-neutron-star mergers are likely to synthesize r-process elements. In this seminar, I will review this event focusing mainly on gravitational waves and the macronova/kilonova.
* The talk will be given in Japanese or English, depending on the audience.
詳細はこちら。
セミナー(2017.9.8)：関澤一之氏 (ワルシャワ工科大学)
2017年9月5日 | 新着情報
2017年９月8日（金）にワルシャワ工科大学の関澤氏による以下のセミナーを開催します。興味のある方はぜひお越し下さい。
Speaker: Kazuyuki Sekizawa (Warsaw Institute of Technology)
Title: Time-Dependent Density Functional Theory for Nuclear Many-Body Problem
Abstract: Time-dependent density functional theory (TDDFT) has shown a great success in describing dynamic phenomena in quantum many-body systems. I have studied nuclear many-body problem using TDDFT, such as dynamics in the neutron star crust as well as low-energy heavy ion reactions. In the seminar, I will briefly review my recent activities and discuss selected topics including some preliminary results.
Date/Time: September 8th (Fri), 2017 / 13:30 –
Place: Conference Room D, Center for Computational Sciences (2F), University of Tsukuba
集中講義 (2017.11.6-8)：Andrea Vitturi氏（Padova大）
2017年8月22日 | 新着情報
今年度、イタリア・パドバ大学のAndrea Vitturi氏による集中講義を筑波大学・計算科学研究センターにおいて予定しています。
Lecturer: Prof. Andrea Vitturi (University of Padova)
Title: Interplay of nuclear structure and reaction mechanism in the description of heavy-ion collisions
Date/Time: November 6-8, 2017; 10:00 – 17:00
Place: Conference Room A, Center for Computational Sciences, University of Tsukuba
Abstract: I will discuss the main features of direct reactions induced by heavy ions, with particular focus on nuclear structure inputs (and outputs). Heavy-ion reactions offer a large variety of final channels (elastic, inelastic, transfer, break-up, fusion, knock-out, charge-exchange, etc) that, coupled to a proper choice of the kinematical conditions as scattering angle or bombarding energy, can single-out specific aspects and properties (static and dynamic) of the nuclear systems. In addition, the usual scenario gets novel features in the case of reactions involving weakly bound nuclei. In fact, the peculiar extension of the nuclear density and the close vicinity of the continuum threshold require novel formalisms for the description of the reaction mechanisms, in parallel with the necessity of revising current structure models.
A list of arguments is as follows:
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Basics in heavy-ion reactions. Semi-classical approximation and coupled-channels
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Elastic scattering. Optical model. The case of weakly bound nuclei
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Coulomb excitation. One-step and multistep reactions.
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Nuclear inelastic excitations. Single-particle and collective excitations. Excitation of giant resonances
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Dipole excitations with isoscalar and isovector probes. GDR and PDR
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Breakup reactions and continuum discretization
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Interplay of different channels: reactions in one dimension as toy model
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Subbarrier fusion. Coupling to internal degrees of freedom. The case of weakly bound nuclei.
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Algebraic approaches (IBM, IBMF, …..). Discrete symmetries and alpha clustering
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Phase transitions and critical point symmetries in even and odd nuclei
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Two-particle transfer
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Two-particle transfer (cont). Giant pairing vibration. Competition of T=0 and T=1 pairs.
RIBF Users Group Thesis Award 2017 (関澤さん)
2017年7月19日 | 新着情報
当研究室の出身者である関澤一之さんが、RIBF Users Group Thesis Award 2017を受賞することが決定しました。関澤さんは2015年に博士（理学）の学位を筑波大で取得し、現在はワルシャワ工科大で活躍されています。
RIBF Users Group Thesis awards は、RIBFに関連する実験・理論の研究によって博士号を取得した人で、特に大きな成果をあげた若手研究者に授与されます。
つくば不安定核セミナー開催（2017.7.26)
2017年6月27日 | 新着情報
第３９回つくば不安定核セミナーを以下のように開催します。また、このセミナーに先立って、上記と同じ場所で、13:00-14:00、14:30-15:30の予定で、渡邊先生に「崩壊核分光法による核構造研究」についての講義をして頂きます。
講師：渡邉 寛（北京航空航天大学）
日時：2017年7月26日(水) 16:00 ~
場所：筑波大学 総合研究B棟1階 B112講義室
概要：Rare-earth (RE) isotopes in the vicinity of the double mid-shell at Z = 66 and N = 104 are exemplary cases of well-deformed nuclei in which the energy levels are characterized by collective rotations and surface vibrations, as well as by quasi-particle excitations. The presence of these excitation modes within a narrow range of energy causes interplay among them to a greater or lesser extent, giving rise to a rich variety of structural aspects in deformed nuclei. Besides their importance for nuclear structure study, the decay and deformation properties of neutron-rich RE isotopes are suggested to play a crucial role in the formation of the so-called RE-element peak around A = 165 in the r-process solar abundance distribution.
Despite such a broad range of interest, spectroscopic information still remains scarce due to the experi- mental difficulties in producing neutron-rich nuclei around and beyond the double mid-shell. The advent of the third-generation in-flight fragment separator facility, the RI-Beam Factory (RIBF) at RIKEN, enables access to this exotic area and allows for systematic studies of their decay properties [1]. In this seminar, I will present the results of β-decay half-lives [2] and β-γ/isomeric-decay spectroscopy [3] of neutron-rich RE isotopes obtained as part of the EURICA (EUROBALL-RIKEN Cluster Array) project at RIBF, along with a discussion about their impact on nuclear structure and nuclear astrophysics.
Despite such a broad range of interest, spectroscopic information still remains scarce due to the experi- mental difficulties in producing neutron-rich nuclei around and beyond the double mid-shell. The advent of the third-generation in-flight fragment separator facility, the RI-Beam Factory (RIBF) at RIKEN, enables access to this exotic area and allows for systematic studies of their decay properties [1]. In this seminar, I will present the results of β-decay half-lives [2] and β-γ/isomeric-decay spectroscopy [3] of neutron-rich RE isotopes obtained as part of the EURICA (EUROBALL-RIKEN Cluster Array) project at RIBF, along with a discussion about their impact on nuclear structure and nuclear astrophysics.
[1] T. Nakamura, H. Sakurai, and H. Watanabe, Prog. Part. Nucl. Phys. (in press). [2] J. Wu et al., Phys. Rev. Lett. 118, 072701 (2017).
[3] H. Watanabe et al., Phys. Lett. B 760, 641 (2016).
*The presentation file is written in English, but the talk will be given in Japanese.
China-Japan collaboration workshop on “Nuclear mass and life for unravelling mysteries of r-process”
2017年6月13日 | 新着情報
日本学術振興会と中国・NSFCとの間の二国間協力事業として共同研究「rプロセスの謎解明に向けた核質量と寿命の研究」（日本側代表：中務（筑波大）、中国側代表：S.G.Zhou (CAS-ITP)）が平成２９年度よりスタートしました。本プロジェクトの開始を記念して、以下の日程で筑波大学・計算科学研究センターにおいてワークショップを開催します。
日程：2017年6月26日（月）ー28日（水）
場所：筑波大学計算科学研究センター1F 会議室A
組織委員：中務孝、小沢顕、日野原伸生（筑波大）
セミナー(2017.4.24)：Piotr Magierski氏 (ワルシャワ工科大学)
2017年4月17日 | 新着情報
2017年4月24日（月）にワルシャワ工科大のPiotr Magierski氏による以下のセミナーを開催いたします。また、同時に来日滞在するGabriel Wlazlowski氏によるよりテクニカルな議論も予定しております。
Title: Towards exascale simulations of quantum superfluids far from equilibrium
Lecturer: Piotr Magierski (Warsaw Institute of Technology)
Place/Time: Conference Room D, Center for Computational Sciences 2F / 13:45 pm
Abstract: Superfluidity is a generic feature of various quantum systems at low temperatures. It has been experimentally confirmed in many condensed matter systems, in 3He and 4He liquids, in nuclear systems including nuclei and neutron stars, in both fermionic and bosonic cold atoms in traps, and it is also predicted to show up in dense quark matter. The time dependent density functional theory (TDDFT) is, to date, the only microscopic method which allow to investigate fermionic superfluidity far from equilibrium. The local version of TDDFT is particularly well suited for leadership class computers of hybrid (CPU+GPU) architecture. Using the most powerful supercomputers we are currently able to study a real-time 3D dynamics without any symmetry restrictions evolving up to hundred of thousands of superfluid fermions. It represents a true qualitative leap in quantum simulations of nonequilibrium systems, allowing to make quantitative predictions and to reach limits inaccessible in laboratories. During the talk I will review several applications and results concerning nuclear induced fission and collisions, dynamics of nuclear matter in neutron stars, dynamics of topological excitations in ultracold atomic clouds and prospects to produce a quantum turbulent flow.