The third major contender is the International Linear Collider (ILC), put together by an international collaboration. It will consist of an approximately 30-km-long tube that will accelerate two kinds of particles from the two ends in a straight line, and smash them into each other. It was expected to be located in Japan before scientists there raised concerns about how the government would split the cost of building and running the machine with other countries.

岩手県が誘致を進めるＩＬＣ国際リニアコライダーについての情報発信拠点となっている盛岡市の施設を６月２１日、ドイツからの留学生たちが訪問した。(On June 21, international students from Germany visited a facility in Morioka City, which is a base for disseminating information about the ILC International Linear Collider, which Iwate Prefecture is promoting.)

That interest carried her through her studies all the way to her current PhD program. She is working on research related to the International Linear Collider, a proposed particle accelerator designed to be a “Higgs factory.” It would produce massive amounts of the particle that inspired Nakajima so that scientists can measure it to new levels of precision.

東京大カブリ数物連携宇宙研究機構の横山広美副機構長（４６）は、巨大科学を推進するには「国際分担の態勢をどのように整えるかが重要だ」と強調した。(Hiromi Yokoyama, Deputy Director of the Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, emphasized that “how to prepare for international sharing is important” in order to promote big science.)

ＩＬＣ国際リニアコライダーを学ぶ岩手県盛岡市の施設「オープンラボ」が６月１６日に一般公開された。 (The facility “Open Lab” in Morioka City, Iwate Prefecture, where students study the ILC International Linear Collider, was opened to the public on June 16.)

「科学技術立国」や「デジタル田園都市国家構想」を掲げる岸田政権。ＩＬＣはその実現に大きく貢献する有望な国際プロジェクトだ。千載一遇の好機をものにするのか、それとも尻込みを続けて逃すのか、世界が注視している。（The Kishida administration advocates a “science and technology nation” and a “digital rural city national concept”. The ILC is a promising international project that will greatly contribute to its realization. The world is paying close attention to whether it will be a good opportunity for a thousand times, or whether it will continue to be shy.）

「この１０年間の蓄積で住民理解はだいぶ進んだ。大きなプロジェクトを動かすには民意の力が重要になる。関係自治体と一層連携し、取り組みを進める」と佐藤善仁一関市長。社会が「ウィズコロナ」へ移行しつつあり、誘致のタイムリミットも迫るここからが頑張りどころだ。(“The accumulation of the past 10 years has greatly improved the understanding of the residents. The power of the people’s will is important for moving a big project. We will further cooperate with the relevant local governments and proceed with the efforts,” said Mayor Yoshihito Sato. The society is shifting to “with corona”, and the time limit for attracting is approaching.)

Future W-boson measurements could also happen at proposed electron–positron colliders, such as the International Linear Collider in Japan, the Future Circular Collider at CERN, and the Circular Electron Positron Collider in China

(Paid article) International Linear Collider in Japan, the Compact Linear Collider and Future Circular Collider in CERN, the Circular Electron-Positron Collider in China, etc.

ICFA reconfirms the international consensus on the importance of a Higgs Factory as the highest priority for realizing the scientific goals of particle physics. This view has only strengthened over time based on results from the world’s particle physics facilities.

Several proposals for electron-positron colliders—such as the International Linear Collider in Japan, the Compact Linear Collider, the Future Circular Collider (FCC-ee) at CERN, and the Circular Electron Positron Collider in China (8)—are under consideration in the ongoing discussions for the future of particle physics.