Cosmic Rays and Dark Matter

Shoji Torii, currently Professor Emeritus and Distinguished Guest Research Professor at Waseda University, has dedicated his career to advancing our understanding of high-energy astrophysics and cosmic rays. After earning his PhD in Physics from Kyoto University in 1978, he built an impressive academic journey through positions at the University of Tokyo, Utah State University, and Kanagawa University before joining Waseda University in 2005. As Principal Investigator of the Calorimetric Electron Telescope (CALET) project since 2009, he has led an international collaboration between Japan, Italy, and the United States in developing and operating this sophisticated space telescope aboard the International Space Station. His groundbreaking work with CALET has yielded significant discoveries in cosmic ray electron spectrum measurements, extending up to 7.5 TeV, and has contributed to the search for dark matter signatures in space. His research achievements include numerous influential publications on cosmic ray observations, relativistic electron precipitation, and gravitational wave counterparts, earning him prestigious recognition including the ISAS Special Award in 2018. Under his leadership, CALET has become a crucial instrument in understanding high-energy phenomena in the universe, particle acceleration mechanisms, and the potential existence of dark matter, while also providing valuable data about the space radiation environment. His work spans from early balloon-based cosmic ray observations to leading the CALET Operations Center at Waseda University, where he continues to analyze data and push the boundaries of our understanding of the universe's most energetic phenomena.

Holger Motz currently serves as Professor at Waseda University's Global Center for Science and Engineering, where he specializes in astroparticle physics and cosmic ray research. After earning his PhD in 2011 from Friedrich-Alexander Universität Erlangen-Nürnberg for his work on dark matter search using the ANTARES deep-sea neutrino telescope, he built his career in Japan beginning in 2012 at the University of Tokyo's Institute for Cosmic Ray Research. His academic journey at Waseda University began in 2013 as a postdoc in the Torii Laboratory working on the CALET project, progressing to Assistant Professor in 2014 and Associate Professor in 2018. In October 2023, he was promoted to Professor at the Global Center for Science and Engineering. His research focuses on cosmic ray physics and indirect dark matter detection, making significant contributions to the CALET mission on the International Space Station, where he has helped detect cosmic-ray electrons with energies up to 7.5 TeV. His work spans theoretical and experimental studies related to particle physics, nuclear physics, and cosmic ray physics, establishing him as a key figure in astroparticle physics research.