The 72th Yamada Conference: The 8th Asia-Pacific Conference on Few-Body Problems in Physics (APFB2020) was held in Kanazawa, Japan on March 1–5, 2021. The purpose of the APFB conference is to encourage PhD students and young researchers in Asian countries to study few-body problems in various physics fields. The 1st APFB conference was held in Tokyo in 1999. Afterawards, the following APFB conferences were held: 2nd APFB, Shanghai, in 2002; 3rd APFB, Thailand, in 2005; 4th APFB, Indonesia, in 2008; 5th APFB, Seoul, in 2011; 6th APFB, Adelaide, in 2014; and 7th APFB, Guilin, China, in 2017. The 8th APFB was planned to be conducted in August 2020. However, because of the COVID-19 pandemic, we postponed it to March 1–5, 2021. As the pandemic situation continued well into 2021, we organized the conference in a hybrid format, that is, with participation both online and on-site. The venue for the on-site part of the conference was Bunka hall in Kanazawa, where one large room was prepared for the plenary session and two smaller rooms were prepared for parallel sessions. The conference covered the following topics: few-body aspects of nuclear physics and nuclear astrophysics, few-nucleon systems and their interactions, hypernuclear physics including exotic nuclei, hadron spectroscopy and structure, few-body aspects of atomic and molecular systems, and interdisciplinary aspects of few-body physics. In the Conference, new results and the present status of facilities in the world have been reported: (i) Few-body and many-body experimental programs are reported at RCNP, J-PARC, RIBF, J-LAB, BESII, LHCb, TUNL, Cyric, FRIB, GSI etc. (ii) Neutron and Proton drip line exploration, magic number evolution and halo nuclei have been reported. (iii) They discussed astrophysics problems from view point of few-body problem, Big Bang Nucleosynthesis to r-process nuclei. (iv) Also, it was interesting to discuss on universality in cold atom clusters from study of trimer and tetramer systems. (v) Furthermore, recent observation of \(S=-2\) nuclei, such as double \(\varLambda \) hypernuclei and \(\varXi \) hypernucleis was reported, which was linked to study of Baryon-baryon interaction.

This hybrid conference had approximately 300 participants in total, of which 50 participants attended on-site and approximately 250 attended online. We had 160 domestic participants, about 80 participants from other Asian countries, 40 from Europe, and 15 from the U.S.A. All participants from abroad attended online. APFB2020 featured 36 plenary talks, 10 invited talks in parallel sessions, and 90 contributed talks. The most difficult tasks in the hybrid-style conference was to organize a scientific program and to solve network problems. We also needed to address the differences in time zone among Asian countries, Europe, and the U.S.A. Therefore, we split the plenary session into the morning (for the US time zone) and evening (for the European time zone). The parallel sessions were conducted late in the morning and in the early afternoon. In addition, we carefully prepared a reliable network connection, which was expensive. However, we were concerned about poor network connections from presenters. To avoid this difficulty, we asked them to provide recoded talks in advance. As expected, we had to use some of the recoded talks during the conference because of poor connections. By these efforts, they enjoyed scientific discussion during the conference. And then, the conference was organized successfully.

To encourage young researchers, we selected three best presentations for the APFB-ANPhA prize among the young researchers. Due to the high competition, we additionally selected two presentations for the APFB special award.

After APFB2020 conference, we decided to collect papers from speakers. It should be noted that the papers are not proceedings of APFB2020 by the following reason: the all papers include new results and were reviewed by the referee very carefully. Thus, all papers should be treated as peer-reviewed ones.

The next international Conference on few-body problems in physics will be held in Beijing, China in 2022. We hope that the conference will be conducted entirely on-site as it would be more efficient to conduct discussions on physics in that manner. Finally, we would like to acknowledge Nishina Center, RIKEN, RCNP, RIKEN iTHES, Kyushu University, and Tohoku University as co-host institutes and universities. Furthermore, the conference was hosted by the Yamada Science Foundation through a Grant-in-Aid for Scientific Research on Innovative Areas, titled gClustering as windows on the hierarchical structure of quantum systems (Fig. 1).

Fig. 1
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Group Photo for on-site participants

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