Seminars in academic year 2023

16:35-18:05, Friday 19th January 2024 (Building 6, Room 6111)
Masaki Yang（Saitama University）
The Mystery of the Missing Antimatter: The Origin of Matter Revealed by Neutrinos

　The absence of antimatter in our universe is one of the key themes in modern physics, and neutrino physics plays an important cosmological role from various aspects. In this talk, I will review the basic properties of antimatter and neutrinos, and discuss the possibility of matter production by neutrinos. Finally, I will present recent work on the incompatibility of this matter production with Grand Unified Theory.

梁正樹.pdf
240119梁_東女セミナー.pdf

16:35-18:05, Friday 15th December 2023 (Building 6, Room 6111)
Hidehiko Agata（National Astronomical Observatory of Japan, The Graduate University for Advanced Studies）
On Basic Science and Peace Diplomacy -A Reading of the International Astronomical Union's Ten-Year Strategy

The International Astronomical Union (IAU) is a non-governmental world organization founded in 1919 to promote the development of astronomy through international cooperation. Since the World Year of Astronomy 2009, the IAU has shifted its focus from activities for astronomers to a growth strategy that includes contributions to society, and has implemented a 10-year strategy with goals such as international cooperation, inclusion, development, and education, The company is also working to contribute to the SDGs and world peace. These activities will be introduced, and the importance of international cooperation in basic science and the role it can play for the stability of today's international society will be discussed.

縣秀彦.pdf
東京女子大（縣）20231215.pdf

16:35-18:05, Friday 17th November 2023 (Building 6, Room 6111)
Makiko Nio（RIKEN Nishina Center for Accelerator-Based Science）
Title: Determine the strength of the electron as a magnet and verify the laws of physics

In August 2023, Fermi National Laboratory in the U.S. released a follow-up report on the anomalous magnetic susceptibility (g-2) measurement of muon particles, which is consistent with the 2006 measurement by Brookhaven National Laboratory in the U.S., down to 0.20 ppm (10^{-6}), half the uncertainty of the 2006 measurement. This value is consistent with the 2006 Brookhaven National Laboratory measurement and the uncertainty has been halved to 0.20 ppm (10^{-6}), more than 5σ away from the globally agreed theoretical value based on the Standard Model of elementary particles announced in 2021, but not a sign of new physics. This is because there have been many new developments in the hadron contribution to the theoretical value, and the theoretical value itself is in confusion. The lightest charged lepton, the electron g-2, has also reached an accuracy of 0.12 ppb (10^{-9}), with new measurements published in 2021. To obtain theoretical values, a fine structure constant α of the same precision as that of the leptons is required, but values of 0.20 ppb and 0.081 ppb were obtained in 2018 and 2020, respectively, increasing the possibility of searching for new physics in electron g-2 as well. I will present the current status of these precise verifications in lepton g-2 and discuss our work and prospects in quantum electrodynamics (QED) calculations that make these verifications possible.

仁尾真紀子.pdf
仁尾さん2023.pdf

16:35-18:05, Friday 20th October 2023 (Building 6, Room 6115)
Masako Bando（Aichi University, NPO Einstein）
Title: The Image of Scientists and the Role of Women in the 21st Century−Reflections on My Life

It has been more than 10 years since I started an NPO called "Intellectual Human Resources Network Aiinshutaiin" with Mr. Fumitaka Sato (a classmate of mine since college), saying, "We are 140 years old together. It is small, but we often gather with friends who like to chat. What is most interesting is that the chats have led to unexpected developments, and the NPO has become a place for various activities. Perhaps it is a characteristic of women that they talk about their dreams for the future and then take action. The older generation (am I the oldest?!) ) and those who are just now raising children, as well as graduate students and students who assisted in the parent-child science class organized by the NPO, and now graduates of this class, have more opportunities to chat together. In addition, we have about 10 children from the neighborhood whose mothers have brought them to the class, asking us to teach them about the atom. Of course, sometimes men also come.
    I was the daughter of a merchant in Osaka, and it was a time when people said, "If a woman goes to college, there will be no one to take her as a wife. When I was in high school, I asked my teacher about my future and she said, "Don't just look at today's society. Society is changing, and it is up to you to change it. My husband, who had been my classmate since elementary school, suggested that we go to college together. When I went to graduate school, my father said to me, "You have already studied enough, so you must be satisfied," but my mother always encouraged me, saying, "If you want to go, I will support you." This situation may seem unthinkable to those of you who see it now. However, I loved it when my father told me, "It is the soul of an Osaka merchant to help those around him even if he lives a meager life."
    It is true that women have not been able to achieve the same status as men, but there are many women who have not made a dent and are doing the best they can within their environment to make a difference in the world around them. I have had many experiences that society does not stay still and can be changed. I would like to share my experiences with you. I would be happy if I could deliver the message that I hope everyone will do their best and be in good spirits so that we can create an era in which both men and women can live vibrantly.
坂東昌子.pdf
坂東さん東京女子大F.pdf

16:35-18:05, Friday 7th July 2023
Elisa G. M. Ferreira（Kavli IPMU）
Title: How did the universe begin?

Abstract: We know we live in a universe that is expanding. As time passes by and the universe expands, it gets bigger, colder, and less dense. This means that in the past the universe was smaller, hotter, and denser. All we see and are today came from this initial stage. The model that describes the evolution of our universe from this initial hot and dense phase is called the Big Bang model and compiles our understanding of our universe. However, this initial stage of the evolution of the universe is still a mystery to us and cosmologists have many theories to describe it! In this talk, we are going to discuss the early universe and the models developed to describe the initial evolution of our universe. We are going to discuss the main paradigm, called inflation, and explain how it gives us the universe we observe today. We are also going to discuss alternative models of the evolution of the early universe like bouncing cosmologies, where our universe did not have a beginning but came from a phase of contraction before our current expanding phase, and emerging universes. We are going to discuss the progress and efforts in cosmology to constrain these models and unravel the mystery of the beginning of our universe.
Elisa G. M. Ferreira.pdf
EarlyUniverse_TokyoWomen_ElisaFerreira_final_compressed.pdf

16:35-18:05, Friday 23rd June 2023  (Building 9, 9204)
Keiko Nagao (Okayama U. of Science)
Directional detection of boosted DM from the direction of the Galactic center

Direct detection of dark matter had been considered unable to detect dark matter particles with masses lighter than MeV scale. However, such light dark matter can be boosted by cosmic rays, potentially making their detectable mass range lighter than previously expected. In this talk, I will discuss the detection of the boosted dark matter signals using directional direct detection experiments, particularly those originating from the direction of the Galactic center, and its implications for the underlying physics.
長尾桂子.pdf
20230623nagao.pdf

16:35-18:05, Friday 26th May 2023（Building 9, 9204）
Maura E. Ramirez-Quezada（University of Tokyo）
Compact Stars: a window to new physics

Due to their high densities, compact stars present themselves as ideal candidates for studying novel interactions in the universe. The core of such stars exists under extreme conditions that remain unattainable through experiments conducted on Earth. In this talk, I will discuss two means of investigating new physics through the observation of compact stars, namely: The capture of novel particles at the centre of compact stars, and the production of novel particles at the centre of compact stars. Additionally, we shall provide a concise overview of the current status and future prospects of employing compact stars for the purpose of exploring new physics.
Maura E. Ramirez-Quezada.pdf
MERQ_SeminarTWCU.pdf

16:35-18:05, Friday 19th May 2023  (Building 9, 9204)
Mariko Kimura (Riken)
Why do black holes produce multi-wavelength radiation? - accretion disks as the central engine of transients -

There are various transients, astronomical objects that suddenly brighten, in our universe. Accretion disks around compact objects such as black holes, neutron stars, and white dwarfs are the central engine of many kinds of transients, efficiently releasing the gravitational energy of the gas as huge radiation energy and outflows. The study of accretion disks has progressed in binary systems consisting of a compact object and a normal star. However, many unusual events that cannot be explained by the simple theoretical model have been discovered due to the recent development of time-space astronomy. Currently, it is required to construct a model that can explain a rich variety in transient events. In this talk, I will explain how gas accretes on compact objects and produces a large amount of radiation energy, and introduce the latest studies based on multi-wavelength observations and numerical simulations toward the construction of a unified model.
木邑真理子.pdf
seminar230519.pdf