Fundamental Physics


Particle Theory Group

Staff: Naoyuki Haba (Professor), Nobuhito Maru (Professor)

The Standard Model of elementary particle physics is almost consistent with experiments below O(100) GeV. However, there are still mysteries, for example,

"(a): What is an origin of mass generation?"

"(b): What is an origin of electroweak phase transition?" (which might be strongly related to an origin of Higgs field),

"(c): Why quarks and leptons have 3 copies (same quantum numbers but different masses)?" (which is so-called mystery of generation, and we do not have any clues for it),

"(d): Why neutrino are much lighterthan other quarks and leptons?",

"(e): Why a charge of proton is thesame as minus charge of electron to an accuracy of 10^21",

"(f): What is an origin of parity violation?",

"(g): Why our world id 4 dimension?", etc.

These mysteries implies an existence of fundamental physics behind the Standard Model (Beyond the Standard Model(BSM)), and they are important clues to search the BSM. I have researched the BSM by use of "supersymmetry (SUSY)", "extradimension theory", "grand unified theory (GUT)", "new building model". However, I also guess, the BSM is an as-yet-unknown theory, and the above mysteries are related among themselves through new physics beyond our imaginings. Keeping the possibilities, I intensively try to solve the mysteries with new and creative approaches. I also try to suggest new experiments to find out the BSM.

Theoretical nuclear physics group

Staff: Naoyuki Itagaki (Professor), Wataru Horiuchi (Associate Professor)

The desire to know "the ultimate in the matter" is the instinct of human beings and is the starting point of studying nuclear physics. The nucleus is a quite small object that exists like a grain in an atom. However, this nucleus accounts for more than 99.97% of the mass of the atom. Thus, when we usually say "heavy" or "light", we are indirectly observing the weight of the nucleus. The nucleus is, in fact, such a familiar object. The nucleus provides the interaction that keeps the electrons trapped inside the atom. Then, it is natural to ask a question: how the nucleus itself is formed? We are trying to answer this question.

Typical research topics in progress
  •  Structure and reactions of neutron-rich nuclei: exploring exotic nuclei far from the stability line
  • Development of theoretical models for the unified understanding of the nuclear structure
  • Effects of non-central nuclear forces on the nuclear structure
  • Understanding of nucleosynthesis in the universe and stars (origin of the elements)
  • Neutrino-nucleus reactions in explosive astrophysical phenomena * Exotic atoms involving muon, antikaon, etc.
  • Application of nuclear physics to cancer therapy

Theoretical Astrophysics Group

Staff: Ken-ichi Nakao (Professor), Hirotaka Yoshino (Associate professor)

We aim to deepen our understanding of the universe through the study of physical phenomena under strong gravity. We are now in a very interesting era, and advances in observational and experimental techniques have made it possible to observe the neighborhoods of peculiar celestial bodies called black holes. In addition, there is a possibility to discover unknown properties of gravity through laboratory experiments. In response to this situation, we aim to deepen our understanding of the theory of gravity, to predict cosmic phenomena, and to conduct theoretical research that will lead to the discovery of new physics.



Mathematical Physics Group

Staff: Naruhiko Aizawa (Professor)