DATE2024.11.18 #Awards & Prizes

Professor Emeritus Susumu Shimoura won the “2024 Nishina Memorial Prize”

Professor Emeritus Susumu Shimoura

The Nishina Memorial Prize is the most prestigious prize in the field of physics in Japan and is awarded to researchers who have made outstanding research achievements in atomic physics and its applications in commemoration of the late Dr. Yoshio Nishina.

The award is due to his demonstration of the existence of a strongly correlated state of four neutrons (abbreviated as 4n state), which has remained unexplored for more than half a century. Professor Emeritus Shimoura proposed two different experimental methods using secondary beams of neutron-rich 8He nucleus supplied at the RIKEN RI Beam Factory (RIBF).

The first experiment was performed using the "double charge-exchange reaction (8He + p → p + 4He + 4n)", which has almost no background noise, and four 4n events in the ⁸Be energy spectrum were found. The 8Be measurement was performed using the SHARAQ magnetic spectrometer, constructed mainly by CNS under the Grant-in-Aid for Specially Promoted Research (Principal Investigator: Sakai).

Subsequently, measurements using the "knockout reaction (8He + p → p + 4He + 4n)," which has a higher yield of 4n states, were performed with the SAMURAI magnetic spectrometer, confirming the existence of 4n states with high statistical accuracy and solving a half-century-long mystery.

This result opens up a new research field of "nuclear physics of multi-neutron systems," and is expected to greatly advance research on the three-body nuclear forces among neutrons and the internal structure of neutron stars.

We wish Professor Emeritus Shimoura continued success in his endeavors.

2024 (70th) Nishina Memorial Prize
Please see details from “Press Conference Materials” on the page

（Responsibility：Professor Emeritus Hideyuki Sakai）