An evaluation of "The KEK Super B Factory Project" as one of large-scale research frontier projects was done in June 2022, by the MEXT  (Monbukagakusho, Japanese Ministry of Education, Sports, Science and Technology) and a report (original version in Japanese) delivered in December 2022. Below you can find a short English summary of the main conclusions.

Comprehensive Assessment

This project aims to discover and elucidate new laws of physics beyond the Standard Model by further improving the performance of the SuperKEKB accelerator, which has the world's highest collision performance as an electron-positron collider. The project is very urgent and strategic, and is highly ranked as a plan that can obtain the consensus of the domestic and international research community and the support of society and the public.

In order to achieve the three scientific goals [1. continuation of operation, performance improvement, and data accumulation, 2. maintenance and improvement of apparatus, and 3. experimental data analyses and presentations of scientific outputs. - Ed.] and obtain scientific outcomes based on the excellent achievements to date, Japan is expected to continue to play a leading role in driving cutting-edge particle physics research and maintain its international competitiveness by improving the performance of the accelerator and properly maintaining it, including measures to prevent its aging.

Taking the above into consideration, our assessment is that the new project term should be actively promoted and should be initiated as soon as possible.

Points of Attention

1. Achievement of scientific goals and scientific outcome in the current plan: 

   In the current project term, although we are upgrading the equipment according to the annual plan and conducting physics experiments presently with the highest performance in the world, the goals for  collision performance and the accumulated amount of data have not yet been achieved. In order to yield the expected physics outcomes , the run plan is designed to balance the improvement in collision performance and in the accumulation of data, with the new goals of 30 times better collision performance than the KEKB accelerator and 15 times more accumulated data than the Belle experiment in the new project term.

     While promoting this project, it is important to analyze the challenges concerning the improvement of the accelerator performance, formulate a detailed plan for achieving the goals in this project term, and steadily execute the plan so that the project can continue to lead the world in the face of increasing international competition with other elementary particle physics research projects such as the LHCb experiment at the European Organization for Nuclear Research (CERN). 

     In addition, by achieving the above goals at an early stage, we expect to have significant scientific achievements going beyond those of the Belle experiment (e.g. elucidation of the mysteries of dark matter and the disappearance of antimatter from the universe), which the Belle II experiment can obtain, owing to the upgraded apparatus, in the observation and elucidation of new laws of physics, and spin-off effects in related fields.
    

2. Securing stable operation time:

   In order to steadily achieve the above scientific goals, it is important to ensure stable operation time. On the other hand, due to the recent surge in crude oil prices and exchange rate fluctuations, etc., it is expected that the cost of electricity will be a heavy burden for the promotion of the project, which is considered to affect the future operation costs. Under these circumstances, in order to secure the necessary operating time without assuming a reduction in the time for experiment, it is necessary to consider diversification of finances that do not rely solely on budgetary measures of the government, and to improve the efficiency of operational expenses or by other efforts so that the necessary expenses can be reduced.

     Regarding the diversification of financial resources, it is conceivable to obtain new participation of overseas institutions to the [Belle II - Ed.] collaboration, and to obtain support through cooperation with companies. In addition, although there are issues such as initial investment, there could be room to continue considering the possibility of creating an environment in which a portion of the necessary power can be generated on-site. Efforts are also expected to minimize the impact of soaring electricity costs by prioritizing various researches and reconsidering the schedule to upgrade the equipment.

     On the other hand, it is important that the national government strives to provide appropriate support for the project to be steadily promoted, taking into consideration the social situation and the status of studies and efforts by the executing body.
    

3. Career promotion of young researchers:

   Many young researchers have been participating in the promotion of the ongoing project. By proactively appointing young researchers to responsible positions on the front line, the project provides excellent possibilities that these researchers can be developed by being engaged in the management of an international large-scale project. In the corresponding scientific field of this project [namely, HEP - Ed.], the promotion of this level of large-scale projects plays a major role in fostering young researchers, and it can be said that the expected role of this project continues to be extremely large. It is necessary to continue proactive efforts to support young researchers building up their careers appropriately in the new project term as well.

     In addition, it is necessary to strive to foster researchers who will support future projects by creating an environment in which young researchers can actively come up with ideas and commit to realize these ideas. This is considered worthwhile not only in the view of cultivation of human resources, but also as an effort to achieve the ultimate scientific goals.
    

4. Reinforcement of management as an international project:

   It is recognized that the management of the ongoing project as an international project is functioning properly, but due to Russia's invasion of Ukraine started in February 2022, it can be said that there is a certain impact on the promotion of this project, of which both Russia and Ukraine are the collaborating members.

     Also in the new project term, it is necessary to consider appropriate measures with relevant countries including both Russia and Ukraine, so that the project can be firmly executed through a proper international collaboration. Furthermore, for the long-term operation of the project, it is important that KEK as the executing body should demonstrate strong leadership, continue reinforcing international management, and take measures to lower a variety of risks so that it can deal with such unforeseen circumstances.
    

5. Other Recommendations:

   The contents and research outcomes of the project, such as the origin of matter and the beginning of the universe, are intended to foster intellectual curiosity among all humankind, but they may not be easily understood by the general public. All possible efforts must be made toward promotion of understanding by society and the public and development of future successors, which includes easy-to-understand information dissemination through social media and mass media, tours for elementary, middle and high school students,  corporate training, exchange meetings with citizens, and hands-on learning for undergraduate students.

Note: The performance indicators in the Table above identify minimal objectives that will be used by
reviewers to evaluate progress in future.