Kohsaku Tobioka, an associate professor in the Department of Physics at Florida State University, has received the Invitational Fellowship for Research in Japan from the Japan Society for the Promotion of Science (JSPS). He is the first FSU faculty member to earn this fellowship, which will support his research in Japan from April to July.
“We’re looking to learn more about the origins of the universe, and conducting research across institutions and nations is essential to do so,” Tobioka said. “We need international collaboration to make real progress; it can’t be done with just one laboratory or nation.”
The JSPS fellowship is designed to strengthen international research networks and foster new scientific knowledge. It invites accomplished physics researchers to collaborate with colleagues at the Yukawa Institute for Theoretical Physics at Kyoto University, a recognized center for theoretical physics.
“In the four months of my fellowship, I hope to begin two projects and continue working with Kyoto University researchers after returning to FSU,” Tobioka said.
During his time in Japan, Tobioka will work with Ryuichiro Kitano, a professor at Kyoto University’s Yukawa Institute. Their collaboration will focus on two main areas: dark matter and properties of the Higgs boson. Dark matter is an invisible substance believed to make up most of the mass in the observable universe. The Higgs boson is a fundamental particle that gives other particles their mass through interactions with its field.
For decades, scientists considered the Higgs boson as the last missing part of the Standard Model of particle physics. Its existence was confirmed in 2012 by CERN near Geneva. Several FSU researchers contributed significantly to that discovery.
Tobioka’s current work aims to study how Higgs bosons interact with each other, which could help clarify how the universe began. This research involves planning experiments using a future muon collider—a device that would use muons instead of protons like those used at CERN’s Large Hadron Collider (LHC). Muons are heavier than electrons and allow experiments at higher energies in smaller facilities compared to proton colliders.
“Using protons, like in the LHC, requires a very big tunnel and can be an infrastructure challenge,” Tobioka said. “A muon collider is a smaller, completely new technology. We all want to know where we came from and how the universe came to be, and this essential science has the potential for unpredictable breakthroughs.”
In 2024, Tobioka and former student Shemeran Mahmud published techniques for observing Higgs boson self-interaction using muon colliders.
Tobioka’s research also addresses dark matter detection by using superconducting qubits—advanced quantum computing materials—to sense dark matter waves and explore connections between dark matter and superconductivity.
“Some people call dark matter ‘the mother of galaxies’ because it hosts stars and galaxies,” Tobioka said. “Because our solar system is constantly moving through the galaxy’s dark matter, we may experience a ‘dark matter wind’ which lets us measure that dark matter. Discovering and fully understanding dark matter is a global competition right now.”
Tobioka completed his doctorate at the Kavli Institute for Physics and Mathematics of the Universe at Tokyo University in 2014. He previously held fellowships from JSPS as well as appointments at institutions such as Tel Aviv University, Weizmann Institute of Science in Israel, High Energy Accelerator Research Organization in Japan, Stony Brook University in New York, before joining FSU’s faculty in 2018.
He also participates regularly in FSU’s Saturday Morning Physics program aimed at promoting science engagement among children and community members.
“Professor Tobioka has brought brilliance and energy to both our physics department and the department’s high-energy physics group,” said Paul Cottle, Department of Physics chair. “He’s an intellectual risk-taker who is constantly challenging boundaries.”
Further information about Tobioka’s work can be found on physics.fsu.edu.
