SSI2025 @ Mirai crea, Hiroshima University, 2025/9/24 - 27

Introduction

The Setouchi Summer Institute (SSI) is a workshop that brings together particle- and hadron-physics groups from universities in the Setouchi (Seto Inland Sea) region. The goal is to foster closer ties through invited lectures, research presentations, and related activities. Held annually over three or four days in late August to September, the meeting typically involves around 40 participants. This year, with the aim of nurturing early-career researchers and promoting researcher exchange in particle and hadron physics across the Chugoku and Shikoku regions, we will hold “SSI 2025” as follows.

Schedule / Venue

• Dates: September 24 (Wed) – 27 (Sat), 2025
• Venue: Hiroshima University, Higashi-Hiroshima Campus — Phoenix International Center MIRAI CREA (1F Multipurpose Hall)
  • Access to the Higashi-Hiroshima Campus is available here .
  • For directions to MIRAI CREA on campus, see the “Access” section here .
• Format: In person
• Reginal school of Yukawa institute (YITP-S-25-03)

Invited Lecture

9/25 (Thu)

Divided into two 90-minute parts with a 1.5-hour lunch break in between.

• 10:00 ~ 11:30 13:00 ~ 14:30
  • Lecture 1 (Chair: Takuya Morozumi)
  • Lecturer: Ryuichiro Kitano (Kyoto University, Yukawa Institute for Theoretical Physics)
  • Title: Particle Phenomenology
  • Abstract: This lecture will cover various topics in particle phenomenology. The Standard Model consists of QED, QCD, and electroweak interactions, yet mysteries remain throughout, and research continues toward deeper understanding. Though the theory is largely complete and experimentally verified, little room seems left for major reconstruction. Why, then, are researchers not content to declare it complete? Following the discovery of the Higgs boson at the LHC, particle theory has entered a period of confusion. This talk will consider its future direction.

9/26 (Fri)

Divided into two 90-minute parts with a 1.5-hour lunch break in between.

• 10:00 ~ 11:30 13:00 ~ 14:30
  • Lecture 2 (Chair: Chiho Nonaka)
  • Lecturer: Hidetoshi Taya (Keio University)
  • Title: Fundamentals of strong-field physics and its applications to heavy-ion physics
  • Abstract: Under extreme conditions known as “strong fields,” fascinating phenomena occur that are impossible in ordinary environments. Such strong-field physics is not only expected to be experimentally verified using high-intensity lasers but is also important for understanding astrophysical and high-energy environments such as neutron stars, heavy-ion collisions, and the early universe. Targeted primarily at graduate students, this lecture will discuss: (1) an overview of strong-field physics and its theoretical foundations, including the Schwinger mechanism and particle production, and (2) its applications to strong electromagnetic and color fields in the early stages of heavy-ion collisions.

Oral Presenations

9/24 (Wed)

Session 1 (Chair: Takuya Morozumi) 13:00~14:30

• 13:00 ~ 13:25
  • Title: Hamiltonian formulation of Wilson’s lattice gauge theories (review)
    • Lecturer: Hiroki Shimizu (Hiroshima University)
    • Lecture materials: Click here
• 13:30 ~ 13:55
  • Title: Exploring QCD matter through magnetic field, vorticity, and spin
    • Lecturer: Chiho Nonaka (Hiroshima University)
    • Lecture materials: Click here
• 14:00 ~ 14:25
  • Title: Analysis of phase structure and quantum oscillations under strong magnetic fields in the NJL model
    • Lecturer: Daiji Kimura (Ube National College of Technology)
    • Lecture materials: Click here

Session 2 (Chair: Chiho Nonaka) 15:00 ~ 16:30 Session 3 (Chair: Takeuchi) 16:30~17:30

• 15:00 ~ 15:25
  • Title: The Hubble constant problem and the time variation model of electron mass
    • Lecturer: Akira Toda (Kochi University of Technology)
    • Lecture materials: Click here
• 15:30~15:55
  • Title: Photon regions, shadow observables and constraints from M87* of charged rotating black holes (review)
    • Lecturer: Shogo Takahashi (Hiroshima University)
    • Lecture materials: Click here

Session 3 (Chair: Kota Takeuchi) 16:30 ~ 17:30

• 16:30 ~ 16:55
  • Title: Precise computation of meson masses in the large-N limit of QCD using the space-time reduced model
    • Lecturer: Ken-Ichi Ishikawa (Hiroshima University)
    • Lecture materials: Click here
• 15:30~15:55
  • Title: Possibility of constraining covariant f(Q) gravity under neutron star observations
    • Lecturer: Muhammad Azzam Alwan (Hiroshima University)
    • Lecture materials: Click here

9/25 (Thu)

Session 4 (Chair: Masanosuke Takeshita) 15:00 ~ 16:00

• 15:00 ~ 15:25
  • Title: Evaluation of local dark matter based on simulation data
    • Lecturer: Hatsumo Nakajo (Okayama University of Science)
    • Lecture materials: Click here
• 15:30~15:55
  • Title: Direct detection of boosted dark matter in a two-component dark matter model
    • Lecturer: Keiko Nagao (Okayama University of Science)
    • Lecture materials: Click here

Session 5 (Chair: Nicholas) 16:30 ~ 17:30

• 16:30 ~ 16:55
  • Title: Explosive production of Higgs particles and implications for heavy dark matter
    • Lecturer: Masato Yamanaka (Hiroshima Institute of Technology)
    • Lecture materials: Click here
• 17:00 ~ 17:25
  • Title: The role and classification of boundary conditions in extra-dimensional models
    • Lecturer: Kota Takeuchi (Hiroshima University)
    • Lecture materials: Click here

9/26 (Fri)

Session 6 (Chair: Abdi) 15:00~16:00

• 15:00 ~ 15:25
  • Title: Space-time evolution of critical fluctuations in high-energy heavy-ion collisions
    • Lecturer: Azumi Sakai (Nagasaki Institute of Applied Science)
    • Lecture materials: Click here
• 15:30 ~ 15:55
  • Title: Space-time evolution of critical fluctuations in high-energy heavy-ion collisions
    • Lecturer: Nicholas J. Benoit (Hiroshima University)
    • Lecture materials: Click here

Session 7 (Chair: Chiho Nonaka) 16:30 ~ 17:30

• 16:30 ~ 16:55
  • Title: Collision parameter probability distribution prediction with Kolmogorov-Arnold Network
    • Lecturer: Cendikia Abdi (Hiroshima University)
    • Lecture materials: Click here
• 17:00 ~ 17:25
  • Title: Equation of state of QCD matter at finite density
    • Lecturer: Akihiko Kadouchi (Osaka Institute of Technology)
    • Lecture materials: Click here

9/27 (Sat)

Session 8 (Chair: Tahara Tomoharu) 10:00 ~ 11:30

• 10:00 ~ 10:25
  • Title: Matrix Bootstrap without Positivity
    • Lecturer: Reiji Maeda (Hiroshima University)
    • Lecture materials: Click here
• 10:30 ~ 10:55
  • Title: TBD
    • Lecturer: Yuma Kawakami (Hiroshima University)
    • Lecture materials: Click here
• 11:00 ~ 11:25
  • Title: Holographic superconducting model exhibiting the Meissner effect
    • Lecturer: Reo Kawai (Hiroshima University)
    • Lecture materials: Click here

Session 9 (Chair: Ken-Ichi Ishikawa) 13:00 ~ 14:00

• 13:00 ~ 13:25
  • Title: The evolution of lepton number density distribution of Majorana neutrinos at low energies
    • Lecturer: Takuya Morozumi (Hiroshima University)
    • Lecture materials: Click here
• 13:30 ~ 13:55
  • Title: A new perspective on particle phenomena: 100 years of quantum theory and the possibility of wave packet measurements
    • Lecturer: Kinya Oda (Tokyo Woman’s Christian University)
    • Lecture materials: Click here

Group photo

Organizers

• Kouhei Uno (SSI2025 principal organizer)
• Takuya Morozumi (Hiroshima University staff)
• Daiji Kimura (Ube National College of Technology)