The 18th board meeting of the Asian Nuclear Physics Association (ANPhA) was held at the Institute of Basic Science (IBS), Daejeon, Korea on November 10, 2023. ANPhA also serves as the Division of Nuclear Physics (DNP) for AAPPS. ANPhA’s board meetings were held online from 2020 to 2022, and this year’s meeting was the first in-person meeting after the COVID-19 pandemic. The venue was the Institute for Rare Isotope Science (IRIS) at IBS, where the new radioactive ion beam (RIB) facility RAON (Rare isotope Accelerator complex for ONline experiments) is being constructed. A total of 26 individuals, including 15 board members, 5 observers, and 6 invited guests, attended the meeting. The board meeting was followed by the ANPhA Symposium the next day.

3.1 ANPhA Board Meeting

Several important subjects were discussed, and decisions were made in this year’s board meeting. The applications by Uzbekistan and Singapore were discussed. Bakhadir Irgaziev of the National University of Uzbekistan and Andrew Anthony Bettiol of the National University of Singapore gave overview presentations of the activities in nuclear physics and the applications of their respective countries. Both applications were unanimously approved by the board members, and Uzbekistan and Singapore were admitted as the respective 13th and 14th ANPhA member countries or regions.

Phan Viet Cuong from Vietnam requested support from ANPhA for the Network of National Nuclear Research Institutes (NNRI). NNRI is a regional cooperative agreement for research, development, and training related to nuclear science and technology for Asia and the Pacific region by the International Atomic Energy Agency (IAEA). In principle, the board members agreed that NNRI would be helpful to promote regional cooperation among ASEAN countries for nuclear physics. However, as the program is supported by the IAEA, some participants raised the concern that complications in basic nuclear physics research might be introduced. It was decided that the proponent would provide more detailed supporting documents for further discussion.

Tomohiro Uesaka proposed to form an “A3 consortium” under ANPhA. The A3 foresight program “Nuclear Physics in the 21st Century”, supported by the funding agencies of China (NSFC), Japan (JSPS), and Korea (NRF), started in 2019. The aim of the program is to promote joint experiments based on the existing facilities and the facilities in construction in the three countries and to encourage theoretical collaboration in order to solve key questions in low-energy nuclear physics. To realize these goals, annual meetings to discuss progress and plans for the future were organized. Although the program was seriously affected by COVID-19, it has succeeded in strengthening the collaboration, improving coherence and synergy among the three countries. Some examples are the development of the nuclear-theory library “A3lib” for nucleosynthesis in the Universe, the construction of the detector-array TOGAXSI for the inverse-kinematics knockout reaction studies at RIBF, the DRHBc Mass Table Collaboration, a joint project to develop the collinear laser spectroscopy (CLS) technique and to study the multi-nucleon correlations at various PF and ISOL facilities, and the formation of a pool for state-of-art detectors, such as HPGe, LaBr₃, and TPC, that can be shared in A3’s leading projects.

The A3 consortium proposal suggested to use of the current A3 scheme as a basis to share the status and planning of accelerator facilities, to promote joint developments of experimental devices and theoretical models by combining common interests and complementary expertise, to encourage the exchange of scientists, to continue the efforts to secure funds to exchange human resources, to bridge young-scientist fostering programs, to link the educational programs, and to examine a way to extend the membership to countries other than the present three countries. In general, the board members agreed on the potential benefits of such a group in ANPhA and suggested creating this unit in a Working Group (WG) format. The proponent plans to clarify the role of the “A3 consortium” and its relation to ANPhA in a written document in the future.

Yet another important discussion focused on the long-range plan (LRP) of ANPhA. All board members agreed about the usefulness of creating a LRP for ANPhA. However, the contents of the document might be different from those from NSAC or NuPECC because the target audiences are different. Some examples of the proposed ideas for the contents were focusing on educational aspects and providing comprehensive facility information to enhance collaboration among the member countries. All agreed to form a dedicated preparation group, chaired by Kazuhiro Tanaka, to discuss and determine the character of an LRP that would be suitable for ANPhA.

In the afternoon, all participants of the board meeting had a tour of RAON. Under the guidance of Taeksu Shin, they visited the accelerator control room, injector system, part of the ISOL system, the SCL3 superconducting (SC) linear accelerator (linac), and the KoBRA recoil spectrometer. All were impressed by the achievements of the last 12 years and wished the completion of the high-energy SCL2 linac as planned. The board members decided to have the next board meeting in 2024 in Chinese Taipei. It was also decided that China would host the meeting in 2025 in Huizhou, where HIAF is under construction. Recently, the venue for the 2024 meeting was decided to be in Huizhou City, China and that for the 2025 meeting to be in Chinese Taipei.

3.2 ANPhA Symposium

The ANPhA Symposium was held at the IBS Science Culture Center, located on the main campus of IBS in Daejeon on November 11, 2023. It consisted of talks on the facilities and national activities on nuclear physics. Seung-Woo Hong, director of IRIS, reported the status of RAON. He presented the status and commissioning efforts of the injector system, cryogenic system, ISOL system, and low-energy SCL3 SC linac of RAON. He also showed the successful beam commissioning procedure using the entire SCL3 modules done at the end of May 2023, which accelerated Ar⁹⁺ beams up to 16.4 MeV per nucleon and delivered the beams to KoBRA.

Wen-Chen Chang of Academia Sinica gave a national report on the activities of nuclear physics in Chinese Taipei. Chinese Taipei groups are participating in the experiments at several accelerator facilities worldwide: e.g., Spring8 and J-PARC in Japan, FNAL and JLab in the USA, and CERN for the structure of hadrons. He also introduced the TEXONO low-energy neutrino and dark matter physics program at Kuo-Shen Reactor Neutrino Laboratory (KSNL). In terms of hardware, the Chinese Taipei Instrumentation Detector Consortium (TIDC) has contributed Si sensors to several experiments, such as STAR, sPHENIX, ePIC at BNL, and CMS at CERN.

Kazuhiro Tanaka introduced a forthcoming heavy-ion program of J-PARC in Japan. A proposal for heavy-ion acceleration at J-PARC was submitted to the Nuclear Physics Committee and the Japanese Science Council and accepted as one of the next generation’s big projects. The acceleration of heavy-ion beams in J-PARC requires a dedicated heavy-ion linac and a booster ring. The proposal plans to build the booster ring in two phases: recycling the KEK-PS booster accelerator with a diameter of 12 m in the first phase and building the dedicated heavy-ion booster with a diameter of 50 m in the second phase. The intensity of Au beams in the first phase is expected to be about 10⁸ Hz, which will be enhanced to 10¹¹ Hz in the second phase.

Vandana Nanal of the Tata Institute of Fundamental Research (TIFR) introduced the Indian facilities for nuclear physics. In India, there are three accelerator centers, which are the BARC-TIFR Pelletron Linac Facility in Mumbai, the Inter University Accelerator Center (IUAC) in New Delhi, and the Variable Energy Cyclotron Center (VECC) in Kolkata. The combination of the BARC-TIFR Pelletron accelerator and SC linac accelerates the ion beams up to ~ 10 MeV per nucleon. The research focuses on the nuclear structure, reactions, and hyperfine interactions. VECC is equipped with K = 130 cyclotron and K = 500 SC cyclotron. It also has a dedicated medial cyclotron, which can accelerate protons up to 30 MeV with a current of 500 μA.

Bing Guo of the China Institute of Atomic Energy (CIAE) gave an overview of the Jinping Underground Nuclear Astrophysics (JUNA) experiment and some recent results. Located 2400 m underground, JUNA achieved, to date, the lowest background levels, which allows the experiments to measure key cross sections down to the fb level at stellar energies. JUNA took its first beam data from 2020 to 2021 and published papers that are influential for nuclear astrophysics. A few examples are the discovery of the new resonance at 225 keV in ¹⁹F(p,γ)²⁰Ne and the first measurement of ¹⁹F(p,αγ)¹⁶O in the Gamow window. JUNA will be upgraded to Super JUNA, increasing the beam energy and current by a factor of two, respectively, to cover various unexplored channels in nuclear astrophysics.

As the chair of NuPECC, Marek Lewitowicz at GANIL overviewed the European LRP for nuclear physics, which will be finalized in 2024. The LRP will review all nuclear physics facilities and major achievements, and then identify opportunities and priorities for nuclear science in Europe. The LRP provides national funding agencies, the European Strategy Forum on Research Infrastructures (ESFRI), and the European Commission (EC) with a framework for coordinated advances in nuclear science in Europe.

Tomohiro Uesaka of RIKEN presents the highlights of low-energy nuclear physics in Japan. Some examples are the discovery of ³⁹Na on the neutron dripline, the precise measurement of nuclear masses using the Multi-Reflection Time-Of-Flight (MR-TOF) technique, the molecular structure of ¹⁰Be, evidence of the tetraneutron state, the first observation of ²⁸O, the deduction of the amount of the chiral condensate using the pion as a probe, and the first electron-RI scattering at SCRIT.

Hideyuki Sakai of RIKEN summarized the ongoing effort to search for superheavy elements (SHE) at RIKEN. In 2016, RIKEN discovered ²⁷⁸Nh with Z = 113 using a cold fusion reaction. As the next step, RIKEN plans to discover Z = 119 elements using a hot fusion reaction. For this purpose, the RIKEN Linear ACcelerator (RILAC) and GAs-filled Recoil Ion Separator (GARIS) were upgraded to SRILAC and GARIS-III, respectively. In addition, the SC ECR ion source was added for generating high-intensity beams. The target was prepared in collaboration with Oak Ridge National Laboratory in the USA. The measurement has started in 2020.

Kevin Insik Hahn of IBS introduced the research activities of the Center for Exotic Nuclear Studies (CENS), which consists of four groups: nuclear astrophysics, structure, reaction, and theory. CENS is preparing several detector systems such as the position-sensitive silicon detector system (STARK), super-clover gamma-detection array (ASGARD), and active-target time projection chambers (TexAT_v2 and ATOM-X). CENS is expected to play leading roles in the experiments at RAON as well as other RIB facilities.

Hirokazu Tamura of Tohoku University overviewed the hadron experimental facility of J-PARC and the status of high-energy nuclear physics in Japan. The extension of the hadron experimental facility of J-PARC was selected as the top priority project at KEK, and the construction is expected to start in ~ 2029. After the extension is completed, an additional production target and four new beamlines will be available. He also summarized the Japanese activities in ALICE at LHC, CERN, and Beam-Energy Scan (BES) program of STAR and sPHENIX at RHIC, BNL.

Taku Gunji of the Center for Nuclear Study, at the University of Tokyo summarized the Asian collaboration for the Electron-Ion Collider (EIC) at BNL, USA. Recently, researchers from China, India, Japan, Korea, and Chinese Taipei, who are interested in the EIC project, formed the EIC-Asia Collaboration. The goal of the regional collaboration is to organize the various areas of expertise on detector technologies and to play a leading role in the various projects. Presently, the collaboration is concentrating on developing and building the Si tracking detectors, particle identification (PID) detectors, and calorimeters for the ePIC detector system. The EIC-Asia Collaboration organizes regular workshops and monthly online meetings.

There were four theory-based talks during the symposium. As the first speaker, Furong Xu of Peking University presented Ab initio Gamow shell model calculations, considering the continuum effect. He applied this model to weakly bound or unbound nuclei. The result showed the importance of the coupling to continuum and three-nucleon forces, and to predicting the resonances in tetraneutron and ²⁷,²⁸O states. The second talk was given by Denny Sombillo of the University of the Philippines. He discussed ambiguity in the interpretation of scattering line shapes. In hadron spectroscopy, most of the resonances are observed near the two-hadron thresholds, and they could be explained by different models. He used the uniformized S-matrix and investigated the ambiguity introduced by the pole structure. With a related topic, Atsushi Hosaka of the Research Center for Nuclear Physics (RCNP), Osaka University discussed the structure of exotic hadrons near the threshold. The data requires not only the molecular states but also the compact quark states near the threshold regions. The final speaker, Anthony Thomas of the University of Adelaide, argued that the global QCD analysis of the deep-inelastic scattering (DIS) data from around the world provides a strong hint for the existence of dark photons in the few GeV regions.