Conveners
Nuclear Structure, Spectroscopy and Dynamics: 1
- Emmanuel CLEMENT (GANIL)
Nuclear Structure, Spectroscopy and Dynamics: 3
- There are no conveners in this block
Nuclear Structure, Spectroscopy and Dynamics: 2
- There are no conveners in this block
Nuclear Structure, Spectroscopy and Dynamics: 4
- Emmanuel CLEMENT (GANIL)
Nuclear Structure, Spectroscopy and Dynamics: 6
- Emmanuel CLEMENT (GANIL)
Nuclear Structure, Spectroscopy and Dynamics: 7
- There are no conveners in this block
Nuclear Structure, Spectroscopy and Dynamics: 8
- There are no conveners in this block
Nuclear Structure, Spectroscopy and Dynamics: 11
- There are no conveners in this block
Nuclear Structure, Spectroscopy and Dynamics: 10
- There are no conveners in this block
Nuclear Structure, Spectroscopy and Dynamics: 14
- There are no conveners in this block
Nuclear Structure, Spectroscopy and Dynamics: 12
- There are no conveners in this block
Nuclear Structure, Spectroscopy and Dynamics: 13
- There are no conveners in this block
Nuclear Structure, Spectroscopy and Dynamics: 9
- There are no conveners in this block
Nuclear Structure, Spectroscopy and Dynamics: 5
- Emmanuel CLEMENT (GANIL)
Neutron stars are unique laboratories to probe matter in extreme conditions that cannot be currently reproduced on Earth. The determination of their equation of state (EoS) is a challenge, but it is particularly important since it allows to relate different global neutron-star properties and to link the prediction of astrophysical observables to microphysical properties of dense matter.
In...
Advances in quantum information science have provided new tools and concepts that shed further light on the structure and dynamics of quantum many-body systems and on the underlying forces that govern them. These new insights, together with cross-fertilization and exchange of ideas between fields, are enabling the development of improved methods and algorithms for simulating many-body physics....
Loosely bound nuclei are currently the focus of interest in low-energy nuclear physics. The deeper understanding of their properties, provided by the open-shell model for quantum systems, changes the understanding of many phenomena and opens new horizons for spectroscopic studies of nuclei from the drop lines to the $\beta$-stability valley, as well as for states near and above the particle...
Shell evolution in nuclei far from stability, such as those in the region of $N\geq28$ and $Z<20$, is understood to arise from the complex interplay of orbital interactions, with different interactions accessible in unstable nuclei compared to stability. Experimental studies of these exotic regions provide stringent tests of modern shell model interactions, but are difficult to access...
Alpha decay is known for more than a century, however a global microscopic description of this process has only been successfully developed recently by Mercier et al. [1]. Within the framework of covariant energy density functional, using a least action principle, the half-life of medium and heavy nuclei agree within one order of magnitude with experimental value [2].
Moreover, a new type...
Neutron-rich oxygen isotopes provide a unique probe to test state-of-the-art shell-model interactions such as SFO-tls [1] and YSOX [2]. In particular, 19O and 20O isotopes can be further employed to constrain shell evolution near the drip-lines, a crucial step towards a universal interaction. In this regard, single-nucleon transfer reactions are suitable tools to study the single-particle...
The study of beta decay of neutron rich nuclei is particularly important for many fields in fundamental and applied physics [1]. In nuclear reactors, fission products, through their decays, produce an additional energy called decay heat [2]. The assesment of this energy is essential for nuclear safety since it represents around 7% of the power in an operating reactor and these decays continue...
A. Di Pietro$^1$, N. Szegedi$^1$, P. Figuera$^1$, S. Cherubini$^{1,2}$,M. La Cognata$^1$, L. Guardo$^1$, M. Gulino$^{1,3}$,L. Lamia$^{1,2}$, A. Oliva$^1$, G. Pizzone$^{1,2}$, G. Rapisarda$^{1,2}$, R. Sparta'$^{1,3}$, M.L. Sergi$^{1,2}$, D. Torresi$^1$, A. Tumino$^{1,2}$, T. Davinson$^4$, N. Duy$^5$, J.P. Fernandez Garcia$^6$, S. Heinitz$^7$, S. Hayakawa$^8$, E.A. Maugeri$^7$, M. Milin$^9$, H....
Studying the structure of exotic nuclei near shell closures is a powerful tool to investigate the underlying nuclear forces. The regions around N=20N=20 and N=28N=28 are known to exhibit significant shape transitions arising from a subtle interplay between monopole evolutionโsuch as the tensor forceโand quadrupole excitations leading to deformation.
Previous studies have shown that the...
Since the advent of radioactive ion beam facilities, excited states in exotic neutron-rich carbon isotopes have been an interesting object of study. In the late 90โs, three $^{17}$C resonant states above the $^{16}$C+n threshold were observed using the beta-delayed neutron decay of $^{17}$B [Raimann96]. More resonances were observed in later works using transfer [Bohlen07], proton inelastic...
Over the last decade, remarkable advances have been made in the theoretical description of electromagnetic properties of atomic nuclei, stimulated by a wealth of high-quality experimental data on short-lived radionuclides (see references [1-6]). In particular, nuclear charge radii have proven to be highly sensitive probes of phenomena such as pairing, deformation, or shell closures, and thus...
The neutron-deficient nuclides surrounding $^{100}$Sn, the heaviest doubly magic self-conjugate nucleus, presents a variety of fascinating nuclear structure phenomena. Key nuclear properties, such as atomic masses of exotic nuclei in this area, are crucial for assessing the stability of shell closures and the evolution of single-particle energy levels. Additionally, atomic masses also...
The formation of short-range correlated nucleon-nucleon pairs (SRCs), primarily composed of neutron-proton pairs [1], appears to be a universal feature in atomic nuclei [2]. Interestingly, measurements in electron scattering indicate that protons become significantly more correlated in asymmetric nuclei as a function of neutron excess. This has potential implications for the description of...
Well-bound spherical nuclei can be considered as closed quantum systems that can be described by state-of-the-art versions of the shell model, where nucleons occupy well-localized single-particle states. However, when we move towards the dripline or inject enough excitation energy into the system, the coupling to the continuum and reaction channels becomes more important, forcing the nucleus...
Complete isotopic fission-fragment distributions of 240Pu have been measured, for the first time, as a function of the initial excitation energy. The 240Pu fissioning system was produced through the two-proton transfer reaction between a 238U beam and a 12C target, a surrogate reaction for the neutron-induced fission 239Pu(n,f).
The reaction was measured in inverse kinematics, allowing the...
We discuss the current understanding of the heavy-ion fusion mechanism through the lens of multidimensional stochastic dynamics. Recent developments, including a six-dimensional Langevin formalism with unconstrained motion in mass asymmetry, provide a realistic description of energy dissipation, shape evolution, and angular momentum effects. This approach captures the transition into the...
In this presentation, I will expose some of the latest developments in microscopic nuclear structure calculations from mid-mass to superheavy elements. In a first part, I will present developments and applications for the diagonalisation of shell-model hamiltonians in a Discrete Non-Orthogonal Shell Model (DNO-SM)[1] and its latest implementation DNO-SM(VAP)[2]. The method is based on...
The In-Gas Laser Ionization and Spectroscopy (IGLIS) technique is a powerful tool to study atomic and nuclear properties of short-lived actinides [1]. Such studies are important to understand the atomic level scheme of these heavy elements, strongly influenced by electron correlations and relativistic effects. Laser spectroscopy in a collimated and low-temperature supersonic gas jet produced...
Ab initio calculations of atomic nuclei aim at describing their structure and reaction properties starting solely from the basic interactions between nucleons. In the past decade, thanks to developments in many-body theory and in the modelling of nuclear forces, ab initio techniques have steadily progressed and are now able to reach several tens of isotopes up to mass A~100, as well as...
Giant monopole resonances, and in particular the nuclear breathing mode, play a central role in constraining the incompressibility of nuclear matter - an essential parameter in the nuclear equation of state. Traditionally, these modes have been studied within the Random Phase Approximation (RPA) using phenomenological Energy Density Functionals (EDF), establishing a well-known framework for...
Spectroscopy based on nuclear transfer reactions has been a workhorse for the investigation of nuclear structure for decades and motivated the construction of many high-resolution spectrometers around the world. However, extending this approach to reactions in inverse kinematics, required for most radioactive beams, comes with a loss of resolution due to kinematic compression and kinematic...
In recent decades, ฮณ-ray spectroscopy has experienced a significant technological advancement through the technique of ฮณ-ray tracking, achieving a sensitivity almost two orders of magnitude greater than previous Compton-shielded arrays. This leap forward rivals the milestones achieved since the beginning of ฮณ-ray spectroscopy. Combining ฮณ-ray spectrometers with detectors recording...
In this contribution recent results obtained at the ISOLDE DECAY STATION (IDS) are discussed, together with an insight on future perspectives.
In addition, the new physics opportunities opening up at the upcoming SPES ISOL facility at LNL (Italy) will also be presented, underlying the complementarity of the two facilities.
Many-body Green's functions stands out among microscopic theories for its capability to encapsulate infromation on ground state properties, response and single particle spectroscopy within the same framework. Different aspects of the many-body correlations and dynamics of a given nucleus can then be investigated simultaneously with the same microscopic approach.
The first part of the talk...
The calculation of many-body correlations in atomic nuclei using ab initio approaches requires accounting for virtual excitations, whose number grows factorially with the perturbative order.
Diagrammatic Monte Carlo (DiagMC) is a promising method that efficiently includes high-order excitations. It has been particularly successful in condensed matter physics [1, 2], where it enables the...
The total beta-decay half-lives of neutron-rich nuclei along magic neutron numbers remain largely unknown experimentally, while they are critical inputs for r-process simulations. In this talk, I will discuss our ab initio calculations for the half-lives of $N=50$ isotones. Starting from two- and three-nucleon interactions derived from chiral effective-field theory, we solve the many-body...
Single-j calculations for $(j)^n$ configurations with n = 3,..,2j+1 can be performed using a semi-empirical approach, provided that the energies and absolute electromagnetic transition rates are known for the two-particle (hole) nucleus. This approach was already successfully applied in the case of protons in the $(\pi g_{9/2})^3$ nucleus $^{211}At$ [1]. At the Cologne Tandem Accelerator of...
Synthesis of neutron-rich nuclei is important for the study of Islands of Stability and r-process. However, to produce the neutron-rich nuclei in heavy mass regions will be limited by conventional fusion reactions. Therefore, in recent years, multi-nucleon transfer (MNT) reactions have attracted attention as a method of producing neutron-rich nuclei [1]. However, the reaction mechanism is not...
The Equation of State (EoS) of nuclear matter is related to many topics in nuclear physics. In particular, it is crucial for understanding the structure of compact objects such as neutron stars. In the conservative hypothesis of a purely nucleonic composition of neutron star matter, the EoS is fully determined in terms of the so-called nuclear matter parameters (NMPs), which, in principle, can...
Beta decay of fission products is at the origin of decay heat and antineutrino emission in nuclear reactors. Decay heat strongly impacts reactor safety since it is about 7% of the nominal reactor power during operation and the only power after reactor stop. Reactor antineutrino detection is used in several fundamental neutrino physics experiments and it can also be used for reactor monitoring...
The fission process forms highly excited fragments carrying significant amounts of angular momentum. This formation is generally described via a shape evolution on the potential energy landscape of the fissioning system. Among the aspects that are still hard to describe in this process is the generation of the fragment angular momenta, highlighted by the work of Wilhelmy et al. in the early...
We investigate the occurrence of $\alpha$ clustered states in $^{16}$O at high excitation energies by analyzing $^3$He + $^{13}$C reactions in the 1.4 - 2.2 MeV energy range. We produce refined angular distributions of the differential cross section in absolute units, allowing us to investigate the competition between the $\alpha$ decays leading to $^{12}$C in the Hoyle state and those leading...
Stretched resonances are rather simple nuclear excitations, even though in light nuclei they appear in the continuum energy region. The structures of these states are dominated by a single particle-hole component for which the excited particle and the residual hole couple to the maximal possible spin value available on their respective shells. The simplicity of their configurations results...
Multi-nucleon transfer (MNT) reactions between heavy ions at energies close to the Coulomb barrier have been identified as a powerful tool to populate neutron-rich nuclei in the regions of the nuclear chart close to $^{208}$Pb and in the actinides [1,2]. The same kind of reactions, but employing neutron-deficient projectiles, can also be envisaged to populate the region of static octupole...
A self-consistent description of cluster emission processes in terms of nucleonic degrees of freedom is presented. The starting point is a Woods-Saxon mean field with spin-orbit and Coulomb terms where pairing is treated through standard Bardeen-Cooper-Schrieffer quasiparticles. A residual two-body interaction is introduced in terms of a density-dependent Wigner force having a Gaussian shape...
Due to its low excitation energy around 8.4 eV, the unique $^{229}$Th isomer is the ideal candidate for developing a nuclear clock [1]. Such a clock would be particularly suited for fundamental physics studies [1]. In the past, measuring the isomerโs radiative decay from a large-bandgap crystal doped with $^{229\mathrm{m}}$Th, has proven difficult: the commonly used population of the isomer...
In the last few years, we continued to study light multineutron systems [1] in bound states that were predicted by Migdal [2]. Such possibility, for at least the dineutron, is based on the theoretical substantiation that in the outgoing channel as the product of the nuclear reaction a bound system of two identical nucleons exists beyond the volume of the heavy core of the other nucleons of the...
The pygmy dipole resonance (PDR) is commonly associated with an excess $E1$ strength on top of the low-energy tail of the giant dipole resonance (GDR) close to the neutron-separation energy in stable and unstable heavy nuclei. While its detailed structure, properties, and origin remain a matter of ongoing debates and research, the neutron-skin oscillation picture of this feature still prevails...
Nuclear shape coexistence is essential for exploring the microscopic origins of nuclear deformation [1-4].
The Ca isotopic chain between the two shell closures at N=20 and N=28 is an optimal test
area that can provide key insights into this phenomenon [5-7].
The aim of this work is to perform complete low-spin spectroscopy of even-even $^{42,44}$Ca and odd-even $^{43,45}$Ca isotopes,...
The region around $^{32}$Mg has become a focus of nuclear structure studies due to the disappearance of the $N = 20$ shell closure, giving rise to a so-called island of inversion. As a result of multi-nucleon correlations, the isotopes in this region exhibit ground states dominated by $2p - 2h$ excitations into the $fp$ shell, deviating from the predictions of a harmonic oscillator potential...
Multi-nucleon transfer (MNT) reactions are a promising method for producing neutron-rich heavy exotic nuclei. Many facilities around the world are studying this process to better understand the reaction mechanisms involved, as well as the competing mechanisms using specific projectile/target combinations [1].
The gas-filled recoil separator RITU [2] at the Jyvรคskylรค Accelerator Laboratory...
The so-called ab initio approach to nuclear structure allows to describe atomic nuclei with controlled and systematically improvable approximations.
Such nuclear structure calculations employing interactions derived from chiral effective field theory are nowadays routinely performed in heavy or open-shell systems.
But describing nuclei that are at the same time both heavy and open-shell is...
The pygmy dipole resonance (PDR) refers to a low-lying strength in the dipole response of nuclei, located around the neutron separation energy [1] and associated with neutron excess in nuclei. As of today, the available experimental data do not provide an accurate picture of the fine structure of the PDR. These open questions on its structure and its potential implications on neutron...
The fission process is strongly determined by both the nuclear structure and the nuclear dynamics, which drives the system from its initial state to final break-up through various stages of extreme deformation. The resultant fission fragments, along with the neutron evaporation emerge as promising parameters for elucidating the underlying mechanisms governing the fission process. The VAMOS++...
Asymmetric fission in mass pre-actinide region is a topic of current interest in fission studies. The important observation in this mass region is the asymmetric fission of neutron deficient nuclei. Andreyev et al. [1] have reported asymmetric fission fragment mass distribution in the ฮฒ delayed fission of 180 Hg nucleus about a decade ago. The observed asymmetric mass distribution has been...
Fission reactions induced by relativistic heavy nuclei, in combination with a large acceptance dipole magnet and advance tracking and time-of-flight detectors (SOFIA detection setup at GSI), have recently allowed, for the first time, the complete identification of both fission fragments in atomic and mass number [1].
By using different target materials, one could also favour fission reactions...
A series of recent experiments to perform high resolution gamma ray spectroscopy of nuclear fission have been carried out with the ฮฝ-Ball2 spectrometer [1]. Nu-Ball2 is a state-of-the-art hybrid gamma-ray spectrometer that was developed and constructed at the ALTO facility of IJC Lab in Orsay. Several open questions are currently being addressed such as the evolution of evolution of fragment...
One of the best-known divergences from the independent-particle shell model description of the atomic nucleus is the existence of islands of inversion (IoI) [1]. The N=40 IoI draws particular interest, as 40 was postulated as a non-traditional โmagicโ number, however, later experimental measurements of B(E2) values and E(2+) energies indicated enhanced collectivity through the N= 40 shell gap,...
The Pandya relation connects the interaction between two particles (or two holes) with the interaction between a particle and a hole [1], and follows from the action of the particle-hole conjugation operator in the context of the shell model [2]. The relation has been used extensively to correlate spectra of pairs of nuclei, for example 40K and 38Cl [3]. Many other examples are known...
Over the last five years, generative machine learning has proven to be incredibly powerful in various domains: communications, image processing, graph analysisโฆ The question now is: how can it help improve the microscopic description of complex physical phenomena, such as nuclear fission? In fact, there is currently no theoretical model capable of predicting fission half-lives, yields and...
The Chromium isotopic chain sits half-way in between the magic Ca and Ni isotopic chains and displays the highest level of collectivity of the region [1]. Going from the N = 28 shell closure to the center of the N = 40 Island of Inversion 64Cr, drastic structural changes are observed along the Cr isotopic chain, driven by a complex interplay of single particle and collective behaviors that...
In this talk, a new open-source solver for the nuclear Hartree-Fock-Bogoliubov (HFB) equations will be presented. This solver uses a double set of HO solutions as its basis, allowing an accurate description of highly elongated nuclear states using a relatively small number of basis states. The implemented nucleon-nucleon effective interactions are of D1x, D2x Gogny types. The solver is written...
S. Szilner1, L. Corradi2, T. Mijatoviฤ1, F. Galtarossa3, G. Pollarolo4, E. Fioretto2, A. Goasduff2, G. Montagnoli3, A. M. Stefanini2, G. Colucci5, J. Dikliฤ1, A. Gottardo2, J. Grebosz6, A. Illana7, G. Jaworski5, T. Marchi2, D. Mengoni3, M. Milin8, D. Nurkiฤ8, M. Siciliano9, N. Soiฤ1, J. J. Valiente-Dobรณn2, N. Vukman1
1Ruฤer Boลกkoviฤ Institute, Croatia
2Istituto Nazionale di Fisica...
Neutrinoless double beta decay (0ฮฝฮฒฮฒ) is a rare nuclear process predicted by beyond-Standard Model theories, offering crucial insights into the nature of neutrinos and lepton number violation. A confirmed observation of 0ฮฝฮฒฮฒ would establish the Majorana nature of neutrinos and provide constraints on their absolute mass scale. Among candidate isotopes, the decay of $^{136}\text{Xe}$ to...
As experimental measurements and industrial applications of nuclear fission continue to develop, there is an increasing demand for theoretical models to simulate fission processes with high precision, including both reactions commonly used in applications today and exotic processes involving superheavy nuclei which have not yet been observed. The construction of such a model remains a...
Exceptional points (EPs) are universal features of non-Hermitian systems, where at least two eigenvalues of an operator coalesce into a single eigenvalue, leading to several non-trivial effects like high sensitivity to parameter changes, unconventional behavior of resonances [1], unconventional time behavior [2], among others[3] . Though long studied in mathematical literature, EPs manifest...
I will present part of the results recently obtained by studying the radiative decay of fission fragments populated in 252Cf(sf). Fission fragments were detected and their kinetic energies measured using a twin Frisch grid ionization chamber. This compact detector was surrounded by an array of 54 large volume NaI detectors. For the particular event without neutron emission, the fragments' mass...
The region of neutron-rich nuclei around N = 60 has attracted much interest throughout the years for its unique features, such as the very sudden onset of deformation appearing in several isotopes, precisely at N = 60. Studies of this phenomenon are of great importance in our understanding of shape evolution and shape coexistence [1]. The sudden inversion of weakly and strongly deformed...
Investigating the boundaries of the nuclear chart and understanding the structure of the heaviest elements are at the forefront of nuclear physics. The existence of the superheavy nuclei is intimately linked to nuclear shell effects which counteract Coulomb repulsion and therefore hinder spontaneous fission. In the region of heavy deformed nuclei weak shell gaps arise around $Z$=100 and...
Studying nuclear fission provides insight into the interplay between the dynamic evolution of the compound nucleus and microscopic effects such as shell structure and pairing correlations. Measuring fission fragment yields not only advances our understanding of nuclear structure but also has important applications in nuclear reactor physics.
This work focuses on the evolution of fission...
Exploring the heavy neutron-rich region around and beyond N=126 is one of the major aims of nuclear facilities worldwide. The foremost reason is understanding the nucleosynthesis of the actinides existing in nature, formed only by the rapid neutron-capture process. At the third waiting point, the only observable measured systematically up to date -some beta-decay half-lives near stability-...
The neutron-rich region of the nuclear chart, around mass numbers Aโผ180โ190, is of great interest for investigating nuclear shape transitions and isomerism in deformed nuclei. Isotopes like $^{183,184}$Hf are predicted to host long lived isomeric states and approach a prolate-to-oblate shape/phase transition, which is expected to result in prolate high-K isomers decaying to oblate low-K...
A general description of the fission mechanism considers both microscopical quantities, such as nuclear structure of the fission fragments, and macroscopic effects, like the Coulomb repulsion between the nuclei. The interplay between both quantities prevents, so far, from a fully microscopical description of the interaction. Despite the development of different theoretical models [1] and...
The low energy fission in the actinide region is known to be mainly asymmetric, driven by structure effects of the nascent fragments. Moreover, we know that there is a transition from asymmetric to symmetric splitting for Thorium isotopes. It was assumed that this latter split would be the main fission mode for lighter nuclei. However, unexpected asymmetric splits have been observed again in...
The nuclear equation of state (EoS) plays a key role in many different aspects of modern physics, being fundamental for understanding the structure of nuclear matter, the properties of neutron stars, and the synthesis of heavy elements. While the properties of proton-neutron symmetric matter are relatively well known, the study of asymmetric matter via properties of neutron-rich nuclei became...
Lanthanum ($Z = 57$) and lutetium ($Z = 71$) serve as ideal candidates to study proton-emission effects. Lutetium proton-emitting isotopes, showing oblate deformations, are positioned near the $N = 82$ shell closure while lanthanum proton-emitting isotopes, which exhibit significant prolate deformation, are located far from any shell closures. Comparing these two cases helps disentangle...
Neutron-rich, heavy, EXotic nuclei around the neutron shell closure at N=126 and in the transfermium region are accessible via multinucleon Transfer reactions which feature relatively high cross sections. The wide angular distributions of the multinucleon transfer products lead to experimental challenges in their separation and identification.
We will overcome these challenges with the new...
The nuclear electromagnetic moments provide an essential information about the structure of the state of interest. They are very stringent tests to the nuclear theory. The magnetic dipole moments are especially sensitive towards the single-particle properties of the nuclear wave functions while the electric quadrupole moments give an insight to the nuclear deformation and...
Quantum computing has the potential to provide new algorithms to solve problems that are otherwise untractable classically. Among these problems, one can employ quantum computers to solve quantum many-body problem. In this talk, I will review two different algorithms to attempt and solve the nuclear shell model in quantum computers. One approach is based on variational quantum eigensolvers, a...
Penning traps are widely used in high-precision mass spectrometry to determine atomic masses with exceptional precision and accuracy, playing a crucial role in atomic and nuclear physics research [1]. TRIGA-Trap is a high-precision, double Penning-trap mass spectrometer located in the reactor hall of the TRIGA (Training, Research, Isotopes, General Atomic) research reactor in Mainz, Germany...
Octupole correlations near $N = Z = 56$ are unique in the sense that they occur between particles in the same orbitals for both neutrons and protons. In this region just above $^{100}$Sn, it is expected that enhanced octupole correlations will take place at low and medium spins in the light Te ($Z = 52$), I ($Z = 53$), and Xe ($Z = 54$) nuclei [1]. In this region of the nuclear chart, the...
The JYFLTRAP double Penning trap mass spectrometer at the Ion Guide Isotope Separator On-Line (IGISOL) facility offers excellent possibilities for high-precision mass measurements of radioactive ions. Using the new phase imaging technique (PI-ICR), ground and isomeric states can be separated, enabling independent measurements of their binding energies.
Accurate mass measurements of ground and...
The response of atomic nuclei to external, harmonically oscillating electric fields, i.e., their photoresponse [1], is dominated by their isovector Giant Dipole Resonance (GDR). The existence of the GDR is known for almost a century [2]. Although it is often considered as the archetype of a collective nuclear mode, a variety of fundamental questions to its very nature is still unanswered: What...
Understanding and predicting the evolution of nuclear structure and the novel phenomena in nuclei has long been a pursuit of scientific curiosity.
Conventional methods such as charged particle probes, $\beta$-decay, Coulombic-excitation, and heavy-ion fusion evaporation reactions have been employed so far in the phase space of Shell structure, magic numbers, angular momentum, and excitation...
The study of nuclear fission remains a critical area of research, not only for understanding fundamental nuclear properties but also for its implications in the production of heavy elements in astrophysical environments. In r-process nucleosynthesis, fission barriers play a crucial role as they ultimately limit the mass of nuclei that can be produced. Currently, very limited data on fission...
The nuclear energy-density-functional (EDF) is a successful theoretical tool to describe many properties of a fissioning nucleus up to the generation of the primary fragments [1]. A core ingredient in the EDF-based many-body approaches is the Bogoliubov vacuum wavefunction. Expectation values of observables such as total binding energies or primary fragments mass are widely computed on...
The isospin symmetry is a consequence of the charge-independence of the nucleon-nucleon nuclear interaction. However, the Coulomb interaction breaks the isospin symmetry. Despite the small size of the isospin breaking, it is fundamental to know its value in the best possible way to understand the properties of the isobaric analog state and its role in Fermi $\beta$ decay.
In the case of...
Shape coexistence is a widespread phenomenon in the nuclide chart. Firstly identified in light nuclei, it has now been observed in several mass regions. Around the shell closure Z=50, shape coexistence has been clearly established in several isotopic chains, particularly in the tin and cadmium isotopes. Intruder states have also been identified in the palladium isotopes. Nevertheless, the...
Cadmium isotopes have been thought to be prime examples of nearly harmonic vibrational nuclei. However, recent studies have started depicting a much more complex picture of their structure, highlighting the possibility of multiple shape coexistence. In particular, advanced beyond-mean-field calculations performed for the 110,112Cd isotopes predict a prolate ground state coexisting with three...
Quantum computers offer the promise of efficiently solving problems which suffer exponential scaling with problem size on classical computers. In application to the simulation of physical systems, quantum computers may be able to overcome the explosion of Hilbert space size with particle number, and to deal efficiently with entangled states.
In this contribution, we show some...
The physics of neutrinoless double beta (0ฮฝฮฒฮฒ) decay has important implications on particle physics, cosmology and fundamental physics. It is the most promising process to access the effective neutrino mass. To determine quantitative information from the possible measurement of the 0ฮฝฮฒฮฒ decay half-lives, the knowledge of the Nuclear Matrix Elements (NME) involved in the transition is...
The In-Gas Laser Ionization and Spectroscopy (IGLIS) technique is a powerful tool to study atomic and nuclear properties of short-lived actinides [2]. Such studies are important to understand the atomic level scheme of these heavy elements, strongly influenced by electron correlations and relativistic effects. Also, fundamental nuclear properties still unknown for most of these nuclei, such as...
The generation of the fission fragments spins is one of the least understood mechanism and its theoretical description has been subject to renewed interest following Wilson \textit{et al.} [Nature 590, 566 (2021)]. We report on a study of the radiative decay of fission fragments populated via neutronless fission of $^{252}$Cf(sf). In such rare events the fragments are populated below their...
The search for Alpha-Cluster Condensate State (ACS) in always more heavy nuclei is one of the most intriguing puzzles of nuclear structure. In particular, in2021, Adachi et al. observed three states in $^{20}$Ne at 21.2, 21.8, and 23.6 MeV [1]. Such states have been suggested to be realistic candidates, being their decay well correlated with the underlying ACSs in lighter nuclei [2].In this...
The seniority scheme assumes that the low lying states in a nucleus can be described considering one single orbital, and there is no seniority mixing. The aim of the present paper is to test the validity of this, by focusing on the reduced B(E2) transition strengths, considered to provide more stringent test of the wave function than the excitation energies.
The largest amount of...
The study of the heaviest elements remains a compelling scientific endeavor. By investigation of nuclei in the trans-fermium region, we can learn about the quasi-particle structure, pairing correlations, and excitation modes in these nuclei. Berkeley Lab scientists have led several recent experiments to study the excited level structure of nuclei in this region through prompt and delayed...
The evolution of nuclear shell structure in exotic nuclei provides key insights into the fundamental nature of nuclear forces. In nuclei far from stability, conventional magic numbers can disappear, while new ones may emerge, a phenomenon known as shell evolution [1]. A well-known example is the evolution of the N=28 shell gap from $^{40}$Ca to $^{48}$Ca, which has been successfully explained...
The appearance of a subshell closure in $^{56}$Cr (N=32) is confirmed by the high excitation energy of the 2$_{1}^{+}$ state and the B(E2;2$_1^+\rightarrow$0$_1^+$). Shell model calculations are able to reproduce the energy of the first 2$^+$ state but not the drop of collectivity at N=32 for the Cr isotopes.
The discrepancy between the experimental data and the theoretical calculations for...
The shape coexistence phenomenon was investigated in the Sn isotopes region around A=110, by means of $\gamma$-ray spectroscopy and lifetime measurements of low-spin states. Recent observations of prolate axially deformed $0^+$ states in $^{64,66}$Ni isotopes, with a strongly hindered decay to the first $2^+$ excited state of spherical nature (shape-isomer-like excitations), were reported ...
The Cyclotron Centre Bronowice (CCB) of the Institute of Nuclear Physics of the Polish Academy of Sciences (IFJ PAN) in Krakรณw is a proton therapy center built in the previous decade, where in addition to therapy, the proton beam is used for scientific research. One of the first measurements performed at the Cyclotron Centre Bronowice (CCB) were studies of collective excitations induced using...
L. Corradi1, S. Szilner3, G. Andreetta1,2, E.Fioretto1, A. Goasduff1, A. Gottardo1, A. M. Stefanini1, J. J. Valiente-Dobรณn1, F. Angelini1,2, M. Balogh1, D. Brugnara1, G. de Angelis1, A. Ertoprak1, B. Gongora Servin1, A. Gozzelino1, T. Marchi1, D.R. Napoli1, J. Pellumaj1, R.M. Pรฉrez-Vidal1, M. Sedlak1, D. Stramaccioni1,2, L. Zago1,2, I. Zanon1, P. Aguilera4, J. Benito4, S. Carollo2,4, R....
At present, the research into the synthesis of superheavy elements is being pursued under two main goals. One goal is to synthesize elements with larger atomic numbers, and the other is to reach Island of Stability predicted as the next double magic nucleus. The periodic table is currently marked up to element 118, Oganesson (Og) [1], and experiments are being conducted with the aim of...
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The multi-configurational dynamical symmetry (MUSY) serves as a unifying framework that links the fundamental structure models of atomic nuclei: the shell, collective, and cluster models [1, 2]. It constitutes a composite symmetry where each configuration possesses a usual [U(3)] dynamical symmetry and an additional symmetry that connects these configurations among themselves. As a consequence...
The ISOLDE Superconducting Recoil Separator (ISRS) [1] is an innovative high-resolution recoil separator aiming to extend the physics program of HIE-ISOLDE by using gamma-particle correlations and decay spectroscopy at the focal plane detector. The objective of the ISRSยดs theory group is to predict direct and compound-nuclei production for selected nuclear reactions, aiming to optimize the...
Over the past few years, there has been an increasing interest in exotic nuclear shapes and accompanying symmetries in low energy subatomic physics, both from theory and experimental points of view. We are going to address theoretical calculations employing realistic nuclear structure Hamiltonians to provide trustworthy predictions of the still unknown quantum mechanisms; new concepts are also...
The exploration of neutron-deficient isotopes in the vicinity of the Z = 100 shell gap, offers valuable insight into the nuclear structure and the boundaries of stability for nuclei with extreme neutron-to-proton ratios. To investigate the limits of stability and also the effects of the single-particle states on the decay modes of these nuclei, the neutron-deficient isotopes of mendelevium...
Most of the heaviest nuclei synthesized in recent decades have been obtained using fusion-evaporation reactions. Due to neutron evaporation and the limited choice of beam-target combinations, this mechanism tends to produce mainly neutron-deficient nuclei. In addition, the cross-sections are often small, e.g. 0.5 pb at most for the discovery of 294Og [1]. Multi-Nucleon Transfer (MNT) reactions...
The study of reactions involving weakly bound exotic nuclei is an active field due to advances in radioactive beam facilities. Many of these nuclei can be approximately described by a model consisting of an inert core and one or more valence nucleons. However to properly describe some of these nuclei within few-body models, additional effects must be considered, such as deformations and...
Nuclear isomers, which are longer-lived excited states of atomic nuclei, emerge due to structural peculiarities that impede their decay processes. Advances in measurement techniques are revealing exotic isomeric properties, leading to an ample amount of data on isomeric states. This information is crucial for both fundamental research and interdisciplinary applications across industry and...
Abstract: The accurate determination of reactor antineutrino spectra remains a very actual research topic for which interrogations have emerged in the past decade. Indeed, after the โreactor anomalyโ (RAA) [1] โ a deficit of measured antineutrinos at short baseline reactor experiments with respect to spectral predictions โ the three international reactor neutrino experiments Double Chooz, Daya...
The existence of $^{298}$Fl, the center of the island of stability, has been predicted [1]. To synthesize this nucleus, it is necessary to produce a more neutron-rich compound nucleus than $^{298}$Fl, since the excited compound nucleus cools down by emitting neutrons.
According to this paper [2], the compound nucleus $^{304}$Fl exhibits some interesting mechanisms. One of them is the effect...
The second $0_{2}^+$ state of $^{12}$C at an excitation energy of 7.654 MeV, known as the Hoyle state [1], is crucial for understanding how $^{12}$C is formed in stellar nucleosynthesis. Despite extensive studies, the Hoyle state characteristics remain a challenging topic for nuclear structure theories: many theoretical models predict very different radii and spatial arrangements of this state...
