Why our Universe was bone and how it developed into the present state? Since its birth at the Big Bang, the Universe has experienced various drastic events. Because the Universe is not a stable object, we have to understand and explain the present state as a consequence of dynamical processes the Universe has experienced. Though many events in the History of the Universe have been clarified, many pieces are still missing to understand our Universe today.
Tomonaga Center for the History of the Universe (TCHoU) was founded in October 2017 as a research center at the University of Tsukuba. The mission of the Center is to clarify the genesis of the Universe as well as the origin of matter and life and to construct an integrated view of the History of the Universe, through international and interdisciplinary collaboration of particle, nuclear, and astrophysics as well as resonant cooperation of experimental and theoretical approaches.
Toward this goal, the center has established the following four research divisions:
Please visit
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[About the Center] for an overview of the Center.
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[Projects] for the research projects of the Center.
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[Organization] for the organization and members of the Center.
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[Materials] for reports and introductory materials.
The name Tomonaga Center comes from Dr. Sin-Itiro Tomonaga, the second Nobel Laureate from Japan, who made fundamental contributions in constructing relativistic quantum field theories, the renormalization theory, theory of collective motions, etc. and also a founder of the physics institute at Tsukuba.
Visit Tomonaga Memorial Room, Univ. Tsukuba and Tomonaga Exibition at the University of Tsukuba Gallery for more information about Dr. Tomonaga.
(Photo: Tomonaga Memorial Room)
Mr. Ryuki Kashiwagi, a doctoral student under the supervision of Asso.Prof. Yuji Takeuchi and Assi.Prof. Takashi Iida from the Division of Elementary Particles, received the Student Best Presentation Award at The 4th International Symposium on Frontiers in Terahertz Technology (FTT2025), held at Tokushima University from October 15 to 17.
P-FTT-04: Ryuki Kashiwagi "Sub-millimeter SiO₂ Collector for Far-infrared and Terahertz Light: Toward Neutrino Decay Detection"
A joint research team led by Assistant Professor Takashi Iida of TCHoU has issued a press release regarding the discovery of luminescence properties in Eu-doped CaF2 crystals that vary depending on the type of radiation.
Scintillators are materials that convert the energy of radiation into visible light. In this study, the team made the world’s first observation that Europium (Eu)-doped CaF2 crystals emit a greater proportion of long-wavelength light under α-particle irradiation than under X-ray irradiation. This finding indicates that radiation types may be distinguished by analyzing emission wavelengths, opening new avenues for the development of advanced radiation detection technologies based on scintillators.
Published in Scientific Reports, "Emission Characteristics of Eu2+ and Eu3+ under X-Ray and Alpha Irradiation in Eu-Doped CaF2 Crystals", DOI: 10.1038/s41598-025-17570-5
For more details, see the press release article and the web announcement of the Univ. of Tsukuba.
The meeting serves as a forum for constituent members to deliberate on the center's current activities and future policies. It also aims to facilitate the mutual sharing of research topics and the latest achievements across various fields, fostering free discussions and exchanges of opinions on the potential for interdisciplinary research. We hope participants to promote interaction among the divisions through lively discussions. Please note that the part following the overall report and deliberation by the center director will be open to participants beyond the center's constituent members.
Presentations are in Japanese.
Contact: Prof. Y. Takeuchi
The KEK Detector R&D Platform "Silicon Detector" meeting will be held at the University of Tsukuba from Tuesday, July 1 to Wednesday, July 2, 2025. The goal of this workshop is to promote the activities of the platform by openly discussing current and developing detectors, detectors using new materials, advances and challenges in related technologies, and information sharing on development environments and facilities. This workshop will particularly focus on readout electronics, specifically ASICs and FPGAs, including specifications required in experiments in particle physics and related fields.
Contact: Assi.Prof. S. Hirose
Lectures by astronomers will be held near Tanabata Day. The state-of-the-art research content will be explained in an easy-to-understand manner to the general public. (in Japanese)
Click on the poster for details.
| 13:30 | Erika Ogata | (Univ. Tokyo) | "Unveiling the Evolution of the Universe and Black Holes through Simulations" | |
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| 15:00 | Shunsuke Honda | (Univ. Tsukuba) | "Astronomers on the Antarctic Expedition: The Challenges of a Polar Mission" | |
| 16:30 | End |
Contact: Prof. N. Kuno (TEL: 029-853-5080)
As an extension course of the Univ. of Tsukuba for FY2025>, we hold the course "History of the Universe" (in Japanese) for high school students.

At the TCHoU, researchers in the fields of particle physics, nuclear physics, and cosmology collaborate to advance research that unifies the history of the universe—from the Big Bang to the formation of the present universe. This research aims to elucidate the dark aspects of cosmic history, such as dark matter, dark energy, and dark galaxies. As an exhibit of the Kids' University for Science and Technology Week, we introduced research on cosmic background neutrinos, Antarctic astronomy, quark-gluon plasma, the Higgs boson, and element synthesis through poster and equipment displays, as well as video screenings, so that both children and adults could enjoy them simultaneously.
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Contact: Prof. F. Ukegawa
The 2025 Breakthrough Prize in Fundamental Physics was awarded co-authors of publications based on CERN’s Large Hadron Collider Run-2 data released between 2015 and July 15, 2024, at the experimental collaborations ATLAS, CMS, ALICE and LHCb. They carried out detailed measurements of Higgs boson properties confirming the symmetry-breaking mechanism of mass generation, the discovery of new strongly interacting particles, the study of rare processes and matter-antimatter asymmetry, and the exploration of nature at the shortest distances and most extreme conditions at CERN’s Large Hadron Collider.
Members of the Division of Elementary Particles and the Division of Quark Nuclear Matters, TCHoU, have been deeply involved in the ATLAS and ALICE experiments, respectively, from their start-ups.
Visit also TSUKUBA JOURNAL, CERN news, ATLAS press statement, and ALICE announcement for more information.
TCHoU Workshop of AY 2024 on Particle Physics, organized by the Division of Elementary Particles, is held as follows. This workshop is free to access. Talks are given in Japanese.
Contact: Asso.Prof. Y. Takeuchi
The 2nd Workshop on Highly Baryonic Matter at RHIC-BES and Future Facilities --- beyond the Critical Point towards Neutron Stars --- (WHBM2025) will be held at University of Tsukuba on March 8-9 (Sat-Sun), 2025 in order to discuss about our current understandings and future directions of researches on Quark Gluon Plasma (QGP) and QCD phase diagram, especially related to the first order phase transition and the critical end point, that are expected at high baryon density region in the phase diagram. The main topics to be discussed in the workshop would be on collective flow, vorticity, imaging, correlation, fluctuation and their experimental and theoretical challenges for clarifying the QCD phase structure and the high-density quark-nuclear matter from intermediate- to high-energy heavy-ion collisions in on-going programs at LHC and RHIC beam energy scan as well as future directions at FAIR, LHC/SPS, RHIC/AGS, HIAF and J-PARC etc.
Details of the workshop including the registration form can be found at the website below.

Contact: Prof. S. Esumi
The Division of Antarctic Astronomy is planning to install a 30cm submillimeter telescope at Dome Fuji inland of Antarctica to clarify the evolution process of interstellar gas in the Milky Way. This year, two members have joined the dome team and have begun preparations on-site. Next year, we will finally send the telescope to Antarctica.
(photo by S.Honda)
Visit NIPR Research Team Blog https://nipr-blog.nipr.ac.jp/jare/20250128post-552.html (in Japanese) for more information.
Contact: Assi.Prof. S. Hirose