Table of contents

The International Symposium on `Correlation Dynamics in Nuclei' was held at the Sanjo Kaikan, the University of Tokyo, from the 31 January to 4 February 2005. This symposium was organized on the occasion of the 50th anniversary of the Configuration Mixing theory of Arima and Horie. The symposium was hosted by the University of Tokyo, and supported by the Inoue Foundation for Science, the Japan Atomic Energy Research Institute and the Ministry of Education, Culture, Sports, Science and Technology.

The purpose of the symposium was to discuss theoretical and experimental developments and future prospects in physics of correlation dynamics in nuclei, including topics such as effective interactions, shell model studies of configuration mixing and spin–isospin modes in nuclei. It was shown in many ways and angles that the Arima–Horie theory has been a starting point of a variety of developments of the studies in these fields over many decades. The developments have been enhanced by the expansion of computational capabilities and the progress in accelerators, detectors and radioactive beam facilities.

We enjoyed 28 excellent and lively invited talks and 30 oral presentations in the symposium with about 90 participants. A special session was dedicated to celebrate the 80th birthday of Professor Igal Talmi, who made invaluable and pioneering works in the shell model theory.

Finally, we would like to thank all the speakers and the participants as well as the other organizers for their contributions which made the symposium very successful.

The Kirson-Babu-Brown (KBB) induced interaction approach is applied to the derivation of the sd-shell nucleon effective interactions. We start from a low-momentum NN interaction V_low-k obtained by integrating out the high-momentum components of modern realistic NN potentials beyond a decimation momentum λ. Then a large class of core polarization diagrams are summed up to all orders by way of the KBB self-consistent equations. It is found that the solution of these equations is simplified by the use of V_low-k, which is energy independent, and by treating them in terms of the Green's fuctions in the particle-particle and the particle-hole channels. The effective interactions calculated with the all-order KBB core polarizations and those with the polarization in second-order perturbation theory are found to be rather similar to each other, typical difference between them being less than 10%.

A new effective interaction is proposed for shell-model calculations in the model space consisting of single-particle orbits p_3/2, f_5/2, p_1/2, and g_9/2. Starting from a realistic interaction derived from the nucleon-nucleon potential, Hamiltonian parameters are modified by a least-squares fit to experimental energy data. The resultant interaction JUL32 is tested from various viewpoints. The property of Gamow-Teller transition strength is studied in the full pf-shell model space focusing on nuclei around ⁵⁶Ni, where the shell-model results show significant dependence on the choice of the effective interaction.

The magnetic dipole (M1) and Gamow–Teller (GT) response are prime examples to illustrate the importance of configuration mixing for an understanding of elementary excitation modes of the nucleus. Starting from the ''classical'' problem of quenching - whose proper description is still beyond the capabilities of microscopic models after all those years — I want to address some current developments of the field. Mandatory for the progress are high-resolution data from electron and hadron scattering and charge-exchange reactions.

In medium-mass fp-shell nuclei, the detailed knowledge of the M1 and GT strength distribution provides a stringent test of state-of-the-art shell-model calculations, validating their applicability in astrophysical network calculations. As an example, it is demonstrated that high-precision M1 data on N = 28 isotones from electron scattering at Darmstadt permit the extraction of neutral-current neutrino-nucleus scattering cross sections important for supernova dynamics and nucleosynthesis.

Fine structure of the GT mode is not only observed in light and medium-mass nuclei, but also in the GT resonance observed in a heavy nucleus like ⁹⁰Nb studied in the ⁹⁰Zr(³He, t) reaction at Osaka with a resolution ΔE ≃ 50 keV (FWHM). Novel methods, based on wavelet transforms, to extract scales characterizing the fine structure are presented. This in turn permits an interpretation of the physics underlying the phenomenon. These methods can also be used to extract spin- and parity-resolved level densities in a nearly model-independent way, again important to test models used in various astrophysical scenarios.

As a final example, the influence of configuration mixing on the GT strength distribution at low energies is investigated for the heavy odd-odd nuclei ¹³⁸La and ¹⁸⁰Ta. The nucleosynthesis of these exotic nuclides, amongst the rarest in nature, is a long-standing problem. A likely source are charged-current neutrino-nucleus reactions which would be dominated by the GT response. However, the main GT resonance lies above the particle threshold and, therefore, does not contribute. Recent measurements of the GT strength distributions in ¹³⁸La and ¹⁸⁰Ta below the particle threshold and their astrophysical implications are discussed.

Both the Gamow–Teller (GT) and the pionic response functions are investigated in the same framework of the continuum random phase approximation with the π ρ + g' model interaction. The Landau–Migdal (LM) parameters, g'_NN and g'_NΔ, are estimated by comparing these calculations with recent experimental data. The peak of the GT resonance and the pionic response functions below the quasielastic scattering (QES) peak constrain g'_NN, whereas the quenching of the GT total strength and the enhanced pionic strength around the QES peak provide information about g'_NΔ. We obtain a common set of the LM parameters, g'_NN = 0.6–0.7 and g'_NΔ = 0.2–0.4, which reproduce the peak and quenching of the GT strengths as well as the enhancement of the pionic modes. The g'_NΔ value is significantly smaller than g'_NN, which means that the universality ansatz, g'_NN = g'_NΔ, should not be valid.

Magnetic moments of nuclei have attracted the attention of nuclear physicists since the early days. Magnetic moments of atoms played an important role in the development of quantum theory of the atom. They were easy to measure and their values posed puzzles which were solved only when the spin of the electron was discovered. Magnetic moments of nuclei were more difficult to measure but they also showed the promise of leading to deeper understanding of nuclear structure. Of particular interest were magnetic moments of odd-mass nuclei. They are the only ones to be discussed in this paper.

Development of theories of configuration mixing is reviewed, concentrating on their application to spin–isospin modes, especially to the Gamow–Teller transitions. This talk is divided into three historical stages, the first order configuration mixing as the first stage, the second order configuration mixing as the second stage, and the delta–isobar-hole mixing as the third stage.

Igal Talmi's Scientific career started in the early years of the shell model. He was responsible for much of the standard machinery and basic approaches of the shell model and his ideas provided insights relevant to the microscopic foundations of the interacting-boson model. His papers were supplemented by two comprehensive books which enlightened practitioners of both models.

A brief review of the history of the use of many-body perturbation theory to determine effective operators for shell-model calculations, i.e., for calculations in truncated model spaces, is given, starting with the ground-breaking work of Arima and Horie for electromagnetic moments. The problems encountered in utilizing this approach are discussed. New methods based on unitary-transformation approaches are introduced and analyzed. The old problems persist, but the new methods allow us to obtain a better insight into the nature of the physics involved in these processes.

For the last 50 years theory and experiment have made huge strides in the understanding of the structure of low lying levels in nuclei from the perspective of electromagnetic moments. However, while both theoretical and experimental techniques have become considerably more sophisticated and have reached high degrees of precision, a close comparison between calculation and measurements still eludes us, except in a few selected cases. In general, trends can be well described for a given family of nuclei. But even the evolution of structure as a function of N or Z, or spin within a single nucleus, is still mysterious. A discussion of the latest developments in experimental techniques, measurements with radioactive beams of ⁷⁶Kr and ¹³²Te, and future prospects will be presented.

The measurements of nuclear moments have been conducted at RIKEN for the study of nuclei far from the β stability. Recent results for the magnetic moments of ³⁰Al and ³²Al obtained by means of β-NMR spectroscopy with spin-polarized radioactive beams from the projectile fragmentation reaction are presented. Remarks are also made on the developments and prospects for future moment studies at the RI Beam Factory.

The nuclear structure of ground states and low-lying excited states of even-even isotopes around ¹³⁴Ba is described using the nuclear shell model microscopically. These structures are revealed to show various phenomena of quadrupole collective states, including the transition of spherical, axially symmetric deformed and triaxially deformed shapes and the realization of the critical point symmetry, E(5).

The ab initio No-Core Shell Model (NCSM) begins with an intrinsic Hamiltonian for all nucleons in the nucleus. Realistic two-nucleon and tri-nucleon interactions are incorporated such as those recently developed from effective-field theory and chiral perturbation theory. We then derive a finite basis-space dependent Hermitian effective Hamiltonian that conserves all the symmetries of the initial Hamiltonian. The resulting finite Hamiltonian matrix problem is solved by diagonalization on parallel computers. Applications range from light nuclei to multiquark systems and, recently, to quantum-field theory including systems with bosons. We present this approach with a sample of recent results.

After a brief historical review, we present recent progress in our understanding of nuclear forces in terms of chiral effective field theory.

Microscopic nuclear structure calculations have been performed within the framework of the unitary-model-operator approach. Ground-state and single-particle energies are calculated for nuclei around ¹⁴C, ¹⁶O and ⁴⁰Ca with modern nucleon–nucleon interactions.

The importance of nucleon knockout experiments for a deeper understanding of nucleon properties in the nuclear medium is clarified. Results of (e, e'p) experiments yield a clear picture of the importance of configuration mixing at all energy scales. A comparison of experimental data with Green's function calculations indicates that a quantitative understanding of the properties of protons in the nuclear ground state is within reach. The latter feature makes nuclear physics the first branch of physics where such an understanding of the in-medium properties of strongly interacting constituents has been accomplished.

Quadrupole collectivity in the proximity of the doubly-magic shell closure at N = Z = 28 has been studied using intermediate-energy Coulomb excitation of ^54,56,58Ni and ⁵²Fe. The results will be summarized and discussed in comparison to large-scale shell model calculations.

A complementary experimental approach sensitive to the single-particle structure of exotic nuclei, one-neutron knockout at intermediate beam energies, has been applied to the proton-rich N = 16 isotones ³⁴Ar, ³³Cl and ³²S as well as to ³²Ar where the knockout residue ³¹Ar is the last particle-bound Z = 18 isotope. The reduction of single-particle strength (''quenching'') compared to shell-model calculations using the USD interaction is discussed in the framework of correlation effects beyond effective-interaction theory.

We report our experimental studies on (p, 2p) reactions from two kinds of view points, namely to investigate single particle properties of nuclei and to observe possible modification of NN interactions in nuclear field. Comparison of the cross section data with theoretical predictions and data of (e, e'p) reaction suggests that the reaction mechanizsm at incident energies of around 400 MeV is simple enough to extract spectroscopic information through the (p, 2p) reactions. In addition, some analyzing power data show anomaly which is not seen in cross section data and, therefore, which suggest importance of polarization studies. On the examination of the NN interaction, systematic study on analyzing powers for 1s_1/2-proton knockout has been continued. A new systematics, a Q-value dependence the analyzing power was newly observed.

We introduce high-resolution (³He, t) reaction at 0° and at an intermediate beam energy as a new spectroscopic tool for studying Gamow–Teller (GT) excitations. Owing to the high energy resolution of the reaction (≈ 30 keV), individual transitions can be observed up to the region of GT giant resonance. In addition, the strengths of GT transitions can now be compared with the strengths of analogous GT transitions from β decays, M1 transitions from γ decays or (e, e') reactions. The study on GT transitions with astrophysical interest, isospin symmetry of nuclei and other related topics are discussed.

Investigating the pair correlation in medium-mass nuclei near the neutron drip-line, we find that the pairing involving several weakly bound neutrons exhibits a significant spatial correlation of the di-neutron type. We suggest that the strong spatial correlation is an inherent property of the pair correlation in nuclear matters at low densities. The di-neutron correlation influences strongly properties of the soft dipole and octupole excitations of the neutron-rich nuclei.

The standard relativistic mean-field density functionals based on non-linear meson exchange terms are extended to include density dependent meson-nucleon coupling constants. Special care is taken for the density dependence in the isovector channel. This provides not only an improved description of the equation of state for neutron matter and asymmetric nuclear matter but also for isovector properties of finite nuclei far from stability such as the neutron skin thickness. In particular it improves nuclear binding energies considerably as compared earlier applications of relativistic density functional theory to nuclear mass tables. An average root mean square deviation of 900 keV is found.

Recently proposed two methods such as Quantum Monte Carlo Diagonalization method in nuclear structure physics and path-integral renormalization group method in condensed matter physics have a similarity as quantum many-body approach, especially in description beyond mean-field approximation. As these two methods have been developed in different fields, there are significant differences as quantum-number projection technique in former method and extrapolation technique in latter method. As these techniques are independent of details of considered system, these can be applied to other fields. In this paper, we discuss how to apply such extrapolation technique to shell model calculations and discuss how to apply quantum-number projection to path-integral renormalization group method.

After a brief review of early developments, two recent examples of applications of symmetries in nuclear physics are presented: (i) pseudo-spin symmetry which can be used to extend Wigner's supermultiplet model to heavy nuclei; (ii) symmetries of the interacting boson model with isoscalar and isovector bosons which can be used to analyze the problem of deuteron transfer in N = Z nuclei.

We discuss the use of the low-momentum nucleon–nucleon (NN) interaction V_low-k in the derivation of the shell-model effective interaction and emphasize its practical value as an alternative to the Brueckner G-matrix method. We present some selected results of our current study of exotic nuclei around closed shells, which have been obtained starting from the CD-Bonn potential. We also show some results of calculations performed with different phase-shift equivalent NN potentials, and discuss the effect of changes in the cutoff. momentum which defines the V_low-k potential.

By using the correlated operators generated within the framework of the first-order perturbation theory, we obtain simultaneously an enhancement of the C6 form factor for ⁵⁰Ti around the first peak, compared to the single-particle-model predition, and a reduction of the C6 form factor for ⁵²Cr in the same momentum-transfer range, both cases being consistent with the experiments. It is the two-body form of the transition operators that plays a crucial role in elucidating this long-standing puzzle.

We discuss the history of the USD interaction for the sd-shell and the progress for determining a new interaction by the inclusion of a more complete set of experimental data including the new data that has accumulated over the last 20 years.

The ground states of all even-even nuclei have angular momentum equal to zero, I = 0, and positive parity, π = +. This feature was believed to be a consequence of the attractive short-range interaction between nucleons. However, a predominance of I^π = 0⁺ ground states was discovered in 1998 using the two-body random ensemble. Since then many efforts have been devoted to understanding and solving this problem from a lot of viewpoints. Still, the underlying physical origin of the I^π = 0⁺ dominance has not been fully understood. Our recent progress in understanding the 0⁺dominance of many-body systems is shown.

The role of isospin asymmetry in nuclei and neutron stars is discussed, with an emphasis on the density dependence of the nuclear symmetry energy. Results obtained with the self-consistent Green function method are presented and compared with various other theoretical predictions. Implications for the equation of state of a neutron star are discussed, and also possible constraints obtained from finite nuclei.

We develop a new type of effective interaction to use in a model-space calculation of finite nuclei. We start with a realistic NN-potential and reduce its model-space with the use of a unitary transformation thereby obtaining the effective NN-potential. We choose the unitary operator to eliminate the hardcore in the central force and to keep the tensor force essentially invariant. We expect that the tensor force can be taken into account to a good extent by using a parity-mixed single-particle state in a model-space calculation.

Spherical-deformed shape coexistence in the N ∼ 20 region is studied with the Monte Carlo shell model calculation. We focused upon the role of the configuration mixing in its description, and found that the deformed state is not correctly positioned until the mixing is treated in a proper way. It is also mentioned that the intruder component in ³³Al is accessible through the measurement of the magnetic moment.

The electric quadrupole coupling constant eqQ/h of ²⁵Na (I^π = 5/2⁺, T_1/2 = 59.6 s), implanted in a TiO₂ single crystal, has been measured by use of the β-NMR technique, to determine the electric quadrupole moment Q. As a result, |eqQ/h| = (44 ± 16) kHz and |Q(²⁵Na)| = (1.0 ± 0.4) mb were determined. From the NMR on ²⁵Na in NaCl, the magnetic moment was determined as |µ| = (3.6832 ± 0.0003) µ_N

Transition strengths of Gamow–Teller decay of T_z = ±1 nuclei to N = Z odd-odd nuclei have been calculated in a two-nucleon approximation for spherical and deformed nuclei. The results obtained for the latter are quite close to the values obtained by full-space shell-model calculations and to the experiment.

The g-factor of the extremely proton-rich nucleus ²³Al (T_1/2 = 0.47 s) has been measured by means of the β-NMR method for the first time. The g-factor were determined as |g| = 1.557(88) from the obtained NMR spectra. From the comparison between the experimental value and the shell model calculation, the spin parity of the ground state of ²³Al was determined as I^π = 5/2⁺. Thus, the magnetic moment of ²³Al was determined as |μ| = 3.89(22)μ_N.

The ¹¹B(³He, t) and ¹¹B(d, d') reactions were measured at forward scattering angles to study the isoscalar and isovector M1 strengths in ¹¹B. Combining the experimental results from the two reactions, the excitation strengths for the isoscalar and isovector spin-flip M1 transitions were successfully determined for the low-lying states in ¹¹B. The obtained strengths were compared with the shell model calculations.

Experimental technique for measuring proton inelastic scattering with high resolution at forward angles including zero degrees have been developed. A good energy resolution of 20 keV with a scattering angle resolution of 0.5-0.9° has been obtained. Detailed analyses for obtaining 1⁺ strength distributions are in progress.

The negative-parity states in ¹³²Ba are studied in terms of the pair-truncated shell model. The model reproduces experimental energy levels of the ΔI = 1 band with the ν(h²_11/2)⊗π(h_11/2g_7/2) configuration. From analysis of its structure, it is found that two angular momentum vectors representing valence neutrons and protons gradually close as total spin increases.

The Gamow–Teller (GT) unit cross section, _GT, is an essential quantity to deduce the GT transition strength, B(GT), from the (p, n) 0° cross section. (p, n) measurements at 200 and 300 MeV were performed using the Neutron Time-of-Flight (NTOF) facility at the Research Center for Nuclear Physics (RCNP). The _GT values were determined, for the first time, for several nuclei in the region of A > 50 at E_p = 200 and 300 MeV. A significant difference between the B(GT) values obtained by (p, n) and (³He, t) measurements was found.

A search for the J^π = 1/2⁻ spin–orbit partner of the J^π = 3/2⁻ ground state in ⁷He has been performed with the ⁷Li(d,²He) charge-exchange reaction. The results are incompatible with recent claims of such a state at very low excitation energy [Meister M et al 2002 Phys. Rev. Lett.88 102501] but rather suggest a resonance with parameters E_x = (1.2^+0.5_−0.4) MeV, Λ = (1.9^+0.8_−0.4) MeV. GT strengths deduced for the transitions to the lowest states in ⁷He are in remarkable agreement with ab initio quantum Monte Carlo calculations.

A generalized two-center cluster model (GTCM), including various partitions of the valence nucleons around two α cores, is proposed for studies on the exotic cluster structures of Be isotopes. This model is applied to the ¹⁰Be = α + α + n + n system. We find that this model naturally describes the formation of the molecular orbitals as well as that of asymptotic cluster states. The application of GTCM to nuclear reaction problem is also discussed.

We investigate the effect of the tensor correlation on the light neutron-rich nuclei. We extend the model space of ⁴He core with the shell model approach to incorporate the tensor correlation, and π-like 0⁻ particle-hole correlation is strongly favored. This affects the LS splitting in ⁵He and the 0⁺₂ state of ⁶He. We also investigate that the tensor correlation is suppressed in ¹¹Li for p² configuration of last two neutrons, which naturally mixes the s² component in the ground state and produces the halo structure.

A set of quantum numbers describing both precessions of total spin and single particle spin is defined by applying boson expansion method to the particle-rotor model with one nucleon coupled to a triaxially deformed core. The derived algebraic energy formula can be applied to classify the triaxial, strongly deformed (TSD) bands in Lu isotopes.

High-spin yrast states in ⁴³Sc were investigated by using in-beam γ-ray technique with the ²⁷Al(¹⁹F,p2n) reaction at 50 MeV. The positive-parity rotational band built on the 152-keV J^π = 3/2⁺ state has been extended up to the terminating J^π = (27/2⁺) state. Several fast transitions feeding to the oblate-deformed J^π = 19/2⁻ isomer have been also identified. the character of the observed levels and transition rates were discussed in comparison with the shell-model calculations.

We propose a new stochastic method to describe low-lying excited states of finite nuclei superposing multiple Slater determinants without assuming generator coordinates a priori. We examine accuracy of our method by using simple BKN interaction.

The structure of ³⁸Ar is investigated by the ³⁴S + α orthogonality condition model (OCM). It is shown that the observed energies and E2 transitions of the superdeformed band are well reproduced by the cluster model.

To investigate structure of ²¹Ne, where the core has a parity asymmetric property, we superpose thousands of Slater determinants. Applying the method we can see importance of α-correlation for several low-lying states and also property of a valence neutron. The ¹³C nucleus is studied as parity asymmetric core with 3α. We confirm the change of spin quantization.

A microscopic interacting boson model calculation is performed for Ba isotopes. The boson interactions are constructed by applying the Otsuka–Arima–Iachello mapping procedure to the phenomenological interactions given in previous systematic studies for A ∼ 130 nuclei. The theoretical energy levels in the IBM are found to be in good agreement with those of the pair-truncated shell model.

The relativisitic mean-field theory explains that the energy difference between hole-states remains constant and that between particle-states increases with neutron excess qualitatively, but not quantitatively.

Relativistic effects on the Gamow–Teller strengths and the sum rule are investigated. It is shown that 6 to 8 % of the sum rule value is taken by the antinucleon degrees of freedom. Most of the quenched amount observed in recent experiment is explained in the relativistic nuclear models. The renormalization of the divergence in the relativistic RPA response function is also discussed.

The connection between the enhancement factor of the photonuclear E1 sum rule and the orbital angular momentum g-factor of a bound nucleon is discussed in the framework of the Landau–Migdal theory for isospin asymmetric nuclear matter, and compared to empirical informations.

The hyperfine structure splitting and the nuclear magnetic moment of ²⁰⁸Pb ±1 nuclei are investigated based on the relativistic field theory. The effects of negative energy states and core polarization are calculated by using the linear response approximation and the lowest order perturbation theory, respectively. The Landau–Migdal parameter is used to fit observed magnetic moments. The HFS splitting energies for ²⁰⁹Pb⁸¹⁺ and ²⁰⁷Tl⁸⁰⁺ are predicted.

An algorithm for the Hartree–Fock–Bogoliubov calculations using the Gaussian expansion method (GEM) have extensively been developed. As well as real-range bases, we take complex-range GEM bases, which are advantageous in including the coupling to the continuum due to the pair correlations. By this algorithm we can obtain appropriate asymptotics of the s.p. wave functions efficiently, and can also handle various interactions including finite-range ones. The method is demonstrated by the spherical HFB calculations for oxygen isotopes.

We perform calculations of the variation after parity projection with Skyrme interaction for ground and excited states of even-even Mg isotopes. Using the 3D real-space representation, we can take into account any kind of deformation; e.g., cluster structure, γ-deformation. We also perform the full 3D angular momentum projection to obtained rotational spectra and B(E2). In ²⁴Mg, the ground K^π = 0⁺ and several odd-parity bands are calculated. In ^30,32,34Mg, our calculation reproduces a breaking of the N = 20 magic number, so-called Island of inversion phenomena. Properties of both the ground and excited states are reasonably reproduced.

Role of pairing correlations unique in low-frequency vibrational excitations of neutron drip line nuclei is discussed. Self-consistent pairing correlations in Hartree–Fock–Bogoliubov (HFB) theory cause the change of the spatial structure of the quasiparticle wave functions; the pairing anti-halo effect in the lower component and the broadening effect in the upper component. By performing HFB plus quasiparticle random phase approximation (QRPA) calculation for the isoscalar quadrupole response in ⁸⁶Ni, we discuss the role of self-consistent pairing correlations for emergency of low-frequency vibrational excitations in neutron drip line nuclei paying special attention to neutrons with small orbital angular momentum ℓ.

We propose a meanfield framework which can treat the correlation induced by the tensor force. To treat the tensor force, we introduce a singe-particle state which is a mixing state of two parities, positive and negative and of two charge states, proton and neutron. We perform both parity and charge projections for a total wave function before variation and obtain a Hartree–Fock-like equation, the charge- and parity-projected Hartree–Fock equation. We apply the equation to the alpha particle and find that a finite tensor correlation is obtained with our method. We also calculate a energy surface for a two-alpha system to study the effect of the tensor force for the alpha clustering in ⁸Be.

Breakup Reactions have been experimentally investigated for the one neutron halo nucleus ¹¹Be and the two neutron halo nucleus ¹¹Li at about 70 MeV/nucleon at RIKEN. We here focus on the breakup with a Pb target, where the Coulomb breakup is dominant over nuclear breakup, and its soft E1 excitation has been a central issue. For ¹¹Be, we present the energy spectra analyzed with the inelastic scattering angle. The selection at very forward angles has been used to extract the E1 strength, which is then applied to obtain the spectroscopic factor of the halo ground state. For ¹¹Li, we have observed significant E1 strength at very low relative energies, which were missing in the previous measurements.

In-beam γ ray spectroscopy is one of the most fruitful experimental methods for the structure study of unstable nuclei performed at RIPS. The experiments become more elaborated following the development of experimental devices and techniques. This paper introduces several experiments recently performed at RIPS utilizing recently developed devices, such as the RF-deflector, liquid helium target, and DALI2 γ-detector array.

Concluding remarks on the Symposium on Correlation Dynamics in Nuclei which celebrates the 50th anniversary of configuration mixing theory of Arima and Horie.