The fifth International Symposium on Physics of Unstable Nuclei – ISPUN17 - was held in Halong Bay, a World Heritage site in Vietnam, from September 25th to September 30th, 2017, to mark 15 years of the ISPUN series which started in 2002 with ISPUN02 held in the same location. ISPUN17 has been organized by the Institute for Nuclear Science and Technology (INST) and Institute of Physics (IOP) in Hanoi, and French counterparts of the collaboration in the nuclear physics research between IPN Orsay (CNRS) and IRFU (CEA) of France and INST and IOP of Vietnam. It was officially endorsed and supported by National Foundation for Science and Technology Development of Vietnam (NAFOSTED), Vietnam Academy of Science and Technology (VAST), CNRS and CEA of France, Helmholtz International Center (HIC) for FAIR, Asian Nuclear Physics Association (ANPhA), and Asia Pacific Center for Theoretical Physics (APCTP). Like previous ISPUN meetings, ISPUN17 has brought together not only the leading nuclear physics experts but also the young physicists, post-graduate and PhD students currently involved in the nuclear physics research for the exchange of the new ideas, information, and presentation of the latest research results. The organizers of ISPUN17 gratefully acknowledge that the participation of a significant number of the PhD students and physicists from several Vietnamese institutions as well as those from abroad was made possible by the valuable financial support from our sponsors.

In a relaxing atmosphere, surrounded by the nice working condition and beautiful view of Halong Bay, the chosen topics of ISPUN17 (Nuclear structure, Nuclear reactions and decays, Nuclear astrophysics, and Nuclear facilities) have been very well covered in the invited talks and oral presentations given by more than 150 participants, coming from 22 countries around the world. Following an established tradition of the ISPUN series, the first plenary session of ISPUN17 has been focused on the research activities and future perspectives of the main nuclear physics facilities in the world. The RIKEN RI Beam Factory (RIBF) was presented by Tohru Motobayashi, who highlighted the interesting results obtained recently in the direct reaction experiments with the unstable beams on the shell structure of dripline nuclei as well as the r-process path of the explosive nucleosynthesis. The current status of the construction of FAIR in Darmstadt and perspectives for the nuclear physics, astrophysics, and applied sciences at FAIR were presented by Thomas Aumann. The audience also learnt about the status and scientific perspectives of FRIB in MSU from the talk given by Paul Mantica. The future subatomic research and application with the high-power lasers at the ELI-NP facility, currently under construction in Bucharest, were highlighted by Sydney Gales and Nicolae Zamfir. More details on future nuclear physics studies with the gamma beams at ELI-NP were discussed later by Calin Ur, Loris D’Alessi, and Paul Constantin. Interesting updates on smaller nuclear physics facilities in Poland, India, and South Africa were presented, respectively, by Adam Maj, Alok Saxena, and Rudolph Nchodu (the first African speaker at an ISPUN meeting). The new in-flight RIB facility in Dubna was briefly introduced by Yulia Parfenova, and Susumu Shimoura told us about the beam degrading facility OEDO, currently under construction at RIKEN RIBF to obtain the high-intensity beams of unstable nuclei at low and medium energies for the direct reaction experiments.

The important experimental setups like AGATA campaign in GANIL, SPES project in Legnaro, the first electron scattering facility for unstable nuclei SCRIT in RIKEN, the ISOLDE facilities and techniques for the laser spectroscopy, the ALTO project in Orsay, and the high-energy nuclear physics program at J-PARC… were discussed in talks given by Bradley Cheal, Mathieu Lebois, Silvia Lenzi, Gianfranco Prete, Ronaldo Garcia Ruiz, Toshimi Suda, Kazuhiro Tanaka, David Verney, and Xiaofei Yang.

Among the chosen topics of ISPUN17, the new trends and forefront research topics of nuclear structure were well presented at our symposium. The recent experimental results on the shell structure, shape transitions and deformations, excitation and decay modes of dripline nuclei were widely discussed in the talks given by Andrei Andreev, Kalle Auranen, Martha Cortes, Pieter Doornenbal, Georgie Georgiev, Philipp Schrock, Olivier Sorlin, and Oleg Tarasov. The efforts to observe different exotic modes of the excitation of unstable nuclei like the double Gamow-Teller giant resonances (Tomohiro Uesaka), the electric dipole response and pygmy states (Atsushi Tamii, Angela Bracco) as well as the high-precision measurement of nuclear lifetimes and masses (Klaus Blaum, Clement Delafosse) have been reported in the sessions of experimental studies. John Sharpey-Schafer, the most senior experimentalist participating in ISPUN17, proposed a range of stiff deformed nuclei based on the systematic data of the γ-ray spectroscopy. Peter Thirolf has shown that a precise measurement of the excited state of 229Th isomer can be a milestone towards a nuclear clock. On the theoretical side, we heard talks on the traditional topics of the mean-field, energy density functional, shell model and nonrelativistic or covariant many-body approaches to nuclear structure (Danilo Gambacurta, Marchella Grasso, Nobuo Hinohara, Elias Khan, Wen-Hui Long, Hiroshi Masui, Jie Meng, Hitoshi Nakada, Takaharu Otsuka, Peter Ring, Hiroyuki Sagawa, Chavdar Stoyanov, Viktor Voronov, Kouhei Washiyama…). The recent progress of the ab initio nuclear structure calculations was shown by Gaute Hagen, Mark Caprio, and Jason Holt. We have also learned about the unified ab initio approach to both nuclear structure and reactions at low energies from Petr Navtratil.

Like previous ISPUN meetings, the physics of nuclear clusters were well presented in both the experimental (Jack Bishop, Tzany Kokalovsa, Yanlin Ye) and theoretical (Makoto Ito, Masaaki Kimura, Peter Schuck, Chang Xu…) contributions. The review talk on α clusters in the stable and exotic nuclei given by Christian Beck is a nice overview of the whole subject. The strangeness nuclear physics, a new subtopic of ISPUN series, has been highlighted in the talks by Kazuhiro Tanaka, Takehiko Saito.

Despite a smaller number of contributions, very interesting talks were given in the sessions of nuclear reactions and decays. On the experimental side, the new information on the single-particle and shell structure obtained from the studies of the nucleon knock-out reactions was discussed by Kathrin Wimmer and Ong Hooi Jin. The low-temperature detectors for the investigation of the fission fragments and the first measurement of the nuclear collective excitations at CCB Krakow were shown by Peter Egelhof and Maria Kmiecik, respectively. Anna Corsi discussed the promising perspectives for the study of neutron skin with the future antiproton beam (PUMA project). The structure effects in the single- and double β decays were discussed by Mathieu Babo and Javier Menendez. The theoretical contributions on nuclear reactions were also interesting and covered different topics, from the extension of the CDCC method to the 4-body systems presented by Pierre Descouvemont to the prediction of a wide range of nuclear reactions for unstable nuclei with TALYS program developed by the IAEA experts (Arjan Koning et al.), the nucleon- and α-cluster transfer reactions (Enrico Vigezzi, Nguyen T.T. Phuc), the nucleon-nucleus and nucleus-nucleus scattering and reaction (Victoria Durant, Takenori Furumoto, Wataru Horiuchi, Doan Thi Loan, Henryk Witala). Naftali Auerbach, the most senior theoretician attending ISPUN17, gave a very pedagogical talk on the single and double charge exchange reactions. New theoretical and experimental results of the fission and fusion studies were discussed in talks given by Gurgen Adamian, Nicolai Antonenko, Radu Budaca, Maria Chusnyakova, Kouchi Hagino, Manoj Sharma, Mohammad Shuaib, and Alexandr Svirikhin.

Nuclear astrophysics, a dynamic field of the modern nuclear physics, is a very special topic of ISPUN17. We heard interesting theoretical talks on the equation of state (EOS) of neutron-rich nuclear matter (Stefano Gandolfi, Ingo Tews) and EOS of the hot hadronic matter of protoneutron star and core-collapse supernova (Shun Furusawa, Ngo Hai Tan). The symmetry energy and its impact on the EOS of nuclear matter as well as the connection to the isobaric analog excitations in finite nuclei were discussed by Pawel Danielewicz and Xavier Roca-Maza. The important role of the weak processes in the stellar evolution and supernova environment was shown by Toshio Suzuki, Myung-Ki Cheoun, and Andrej Vdovin. Very exciting and lively presentations on nuclear astrophysics were given by the leading experimentalists in the field. Beside the talk by Tohru Motobayashi mentioned above, Michael Paul told us how to test the r-process reactions in the laboratory, Shigeru Kubono and Hidetoshi Yamaguchi presented the studies of important astrophysical reactions carried out at CRIB of CNS Tokyo. The interesting perspectives of nuclear astrophysics in the research plan of FAIR were discussed by Karlheinz Langanke. Similar prospect of the experiments planned for the future accelerator center RAON in Korea was shown by Kevin Hahn and Byungsik Hong. In the same trend, Weiping Liu has updated us on the JUNA project currently under construction in China, aiming to measure in the underground laboratory very important astrophysical reactions like 12C(α,γ)16O with the ultra-low background.

The new data of the low-energy reactions taken at INFN-LNS, and the interpretation using the Troyan Horse Method were shown by Aurora Tumino. The nuclear astrophysics studies at the n_TOF facility at CERN were highlighted in the talk by Giuseppe Tagliente. The new low-energy reaction data related to the nucleosynthesis processes were discussed by Javier Praena and Lam Yek Wah.

In general, the scientific program of ISPUN17 has been very lively and covered a broad range of topics being at the forefront of the modern nuclear physics. That is the reason why the organizers found it necessary to have two separate summary talks on the theoretical and experimental contributions, presented at the end of our symposium. The participation of the young scientists has increased significantly this time, and the Board of the Asian Nuclear Physics Association has decided, therefore, to establish the ANPhA prizes for the top three best oral presentations at ISPUN17 by the young physicists (age below 37). It turned out a very strong competition, and the first, second, and third ANPhA prizes have been awarded to Jack Bishop (University of Birmingham), Martha Liliana Cortes (RIKEN), and Shun Furusawa (RIKEN), respectively. We hope very much that the ANPhA awards for the top three best presentations by the young physicists will also be established for the next ISPUN meeting.

Last but not least, the social program of ISPUN17 has been also exciting, which allowed the participants to enjoy the natural beauty of Halong Bay in a boat trip through numerous islets and caves. Watching the sunset aboard the ship Halong Princess Cruise or listening to the beautiful concert of classical music given by the musicians from Hanoi Conservatory remain the unforgettable experiences for all.

Dao Tien Khoa


Nicolas Alamanos

IRFU, CEA Saclay

Gianluca Colo

University of Milan