[No. 111] Masaya Ishino

It was over 20 years ago that I first came to Keio University's Yagami Campus. I joined a relatively new organization as a member of the ninth graduating class of the Department of Physics. I spent the last two years of my university life at a time when the department's overall operations were getting on track and we, as undergraduate students, were beginning to hear about its notable achievements. It was a vibrant period. "My life at Yagami"... It may sound like I'm praising myself, but I believe I studied very hard. The truth is, by studying for long hours, I think I was finally able to get a handle on the tools needed to understand quantum mechanics, which I was encountering for the first time. (Even now, I can hardly say that I truly understand quantum mechanics.)

In the exercise classes that were paired with our lectures, the professors provided us with challenging and fundamental problems, and my friends and I would work on them together every night until the Yagami library closed. This is one of my fondest memories. I remember several occasions when, rather than just solving the problems, we would delve into deeper discussions with friends and senior students, exploring the problems from multiple angles. This process made the inherent fascination of the subject matter come alive in a three-dimensional way. At times like those, I felt from the bottom of my heart how glad I was to be studying physics. I also feel that I was truly lucky to be blessed with friends and senior students with whom I could discuss physics in this way. I wrote "discuss" physics, and looking back, I realize we literally talked a lot. It seems I was always talking about something, not just in exercise classes, but also during experiments, my graduation research, and whatever other tasks we were tackling. The third year of university is a time when students are exposed to a vast number of new concepts, starting with quantum mechanics. I suppose that by explaining things to others and listening to their explanations, I was correcting my own misunderstandings and solidifying the correct concepts. I'm not sure if the people around me found it helpful or annoying—it was probably a bit of both—but they became partners against whom I could thoroughly test my logic and understanding. I believe there are other universities besides Keio University that offer such an environment and atmosphere, but the fact that these opportunities are available at such a high level is an important point that can be a motivating factor when choosing a school.

I spent seven years immersed in the Keio atmosphere, from affiliated high school through university, and it was very comfortable. However, Keio University did not have a laboratory for the elementary particle physics research I was determined to pursue. For that reason, I decided without hesitation to venture into the outside world, and as fate would have it, I went on to graduate school at Kyoto University. My research theme was to find experimental evidence for the theoretical idea proposed by Dr. Yoichiro Nambu, who received the Nobel Prize in 2008: that hadrons acquire mass through the breaking of chiral symmetry. I spent two years in the master's program and three years in the doctoral program developing experimental equipment. After repeating a year three more times, I finally completed the data acquisition, analysis, and my doctoral dissertation. It took me 50% longer than the standard time, but I feel that during this period, I thoroughly developed the fundamental stamina of an experimental physicist.

After that, I spent nine and a half years at the CERN laboratory in Geneva, where I was involved in an experiment to discover the Higgs boson, a key particle in understanding the mechanism by which elementary particles acquire mass, and that is what I continue to do today. Many of you may have learned about this achievement through the newspaper reports on the discovery of a new elementary particle in July 2012 and the Nobel Prize in Physics in 2013. I personally co-developed an experimental apparatus with colleagues from Israel to detect events where the Higgs boson decays into muons. I served as the on-site supervisor for the incredibly diverse international team (with countless members from Pakistan, Israel, China, the United States, and Western European countries) that assembled it into a massive system. I also carried out a series of tasks and research, including operating the detector and evaluating its performance. I am truly glad that we succeeded in developing and operating the experimental apparatus, which was indispensable for this new particle discovery.

With this, the preparations are in place to open up a truly new world of elementary particle physics. The real fun is yet to come. If asked, "Was what you learned at Keio useful in your subsequent research life?" my answer would definitely be "yes." The fundamentals of physics and the method of approaching the unknown without fear, which I acquired through discussing physics with my friends, will continue to be an important foundation for my research, both now and in the future.