Interview date: 2025/06/25
Interviewer: Naomi Ebisawa, Public Relations Office
Mr. Tristan FILLINGER, doctoral research fellow of Institute of Particle and Nuclear Studies (IPNS), was born in France. Two years have passed since he came to KEK. I asked him about his life in Japan.
The first time I met you, you were waiting for foreign visitors to guide them inside your facility. After we chatted for a bit, I immediately wanted to interview you for this series of articles. Thank you for accepting my request. Could you please introduce yourself?
I graduated from Strasbourg University, located in the north-eastern region of Alsace. I got Ph.D. from the Hubert Curien Pluridisciplinary Institute (IPHC). At IPHC, I was part of the group that participated in the Belle II experiment and I visited Japan twice to attend the B2GM (Belle II General Meeting). That is how I came to KEK.
KEK has the office of Toshiko Yuasa Laboratory (TYL)※ and you received the Young Investigator Award from TYL for young researchers in 2023, didn’t you?
Exactly. I received the award for my paper focusing on measuring the time-dependent asymmetry of B->Kres gamma decays, presented at the end of 2022. I talked about the asymmetrical measurement of B meson radiative decay as a function of time. Radiative decay of a B meson is a phenomenon in which a B meson decays into another, lighter meson by emitting a high-energy photon.
Please tell me about your current duties. I heard you gave a presentation at the joint research meeting of B Factory Physics Study Group and New Physics Forum last June. What did you talk about?
I usually spend my time analyzing data. At the joint research meeting, I talked about my study, titled by “Status and prospects for B-> tau nu, mu nu at Belle II”.
Belle II Experiment is quite unique. It would be a great honor for me to contribute to future scientific achievements through data collection and analysis.
Since I came to work at KEK, I have had a chance to talk with some researchers at SuperKEKB. It is very valuable to me. Interaction between different fields is a unique feature of KEK, I think.
One of the reasons I wanted this interview was due to your first name. “TRISTAN” is the abbreviation of the “Transposable Ring Interesting Storage Accelerator in Nippon.” It was named after the Wagner’s opera “Tristan and Isolde”. KEKB was born from TRISTAN, and the current SuperKEKB is an upgrade of KEKB. Did you know about that before coming to Japan?
I didn’t know that at all. It happened before I was born! I was so surprised at knowing the fact when I got here. A name of “Tristan” is not so common in my country. In fact, there is another Tristan in KEK. He is an Australian researcher.
One more thing. When I hear the word “Alsace,” people of my generation are reminded Alphonse Daudet’s “The Last Class/La Dernière Classe” that we read in Japanese literature class in junior high schools. It’s the story of an elementary school in Alsace, which was occupied by Prussia (now Germany) as a result of the Franco-Prussian War and where the use of French was banned. We can’t find it in the textbook now. What was the situation in France?
That is also new to me! Most people around me wouldn’t know, I guess. Neither my parents nor I speak German, but my grandparents do. Alsace dialect and German have the similar backgrounds, so perhaps it is easy for them to understand each other.
I see. Strasbourg, the center of Alsace region, is famous for the Christmas market. What does it feel like?
It’s extremely big, not just on a national scale, but also on a global scale. A cathedral stands in the center of the city, and it’s surrounded by many half-timbered houses. Every year, large Christmas trees are decorated and lit up in each square. It’s very beautiful. You will see many street stalls there, called the Chalets, and they sell a wide variety of goods. I would really love everyone to visit its someday.
Oh, I love to do that someday! So, how do you like Japan to live?
This country is rich in nature and has a peaceful atmosphere. I visited Kyoto once in spring. Cherry blossoms were unbelievably beautiful. There are Sakura trees in France too, but it’s not like in Kyoto. There is no such thing as a picnic like Hanami in the first place. Franch people get together and then generally BBQ begins.
I have been very curious of Japanese architectures, temples, and festivals. During my first year, I lived in Tsukuba and spent my days just going to work and coming home. Now I have moved to Kita-senju (Adachi Ward, Tokyo) and enjoyed exploring various places. Thanks to it, even when I go back to France sometimes, I miss my place in Japan and want to go back soon.
The other day, I went to Zushi beach (Zushi, Kanagawa) to see the fireworks. People in Japan can enjoy the firework events nationwide mainly during the summer season, but in France, we can see the fireworks only on Bastille Day, July 14th, and New Year’s Day.
My favorite Japanese food is tempura! I love avocado tempura, I got once in Shibuya. That’s the best! Pumpkin and shiitake mushroom ones are also good. I’m sorry, but natto one is NOT. If I had been used to having natto since I was a kid, I might have been able to eat it, but now I’m old enough and it’s too late. Don’t you think so?
As for the people here, I’m very impressed by their polite manners with frequent bows. I think it’s a completely different culture from European countries.
Do you have any hobbies?
While I was in France, I played a percussion instrument at a local symphonic orchestra for ten years. Now I play the drums. Do you know Nintendo’s game, “Taiko no Tatsujin”? It’s very cool! I often play video card games.
Are there any places you would like to visit, or any things you would like to try while you are in Japan?
First, I like to go on a trip to Mt. Fuji. I really want to go on a hike and watch the sunrise at the top of the mountain. I also want to visit Hokkaido and Hakone as well. Aoshima (Osu, Ehime) is also. There are a lot of cats living there. I saw it on YouTube.
My research contract has been extended, so I can be here for another three years. During this time, I really want to develop my Japanese skills for the better during this time. Language is so important to stay here long. I can handle hiragana and katakana, but kanji is very challenging. Keigo is also.
You are amazing! Keigo is difficult even for Japanese people. I want to learn French.
Let’s talk with your French and my Japanese next time. I’ll do my best!
I am looking forward to that day coming.
※TYL is a virtual institute jointly managed by French National Institute of Nuclear and Particle Physics, French National Centre for Scientific Research (IN2P3/CNRS) and Institute of Research into the Fundamental Laws of the Universe, French Alternative Energies and Atomic Energy Commission (Irfu/CEA).