For the collaboration:
S. Leoni et al., University of Milano and INFN sez.-Milano, Italy
B. Fornal et al., Institute of Nuclear Physics PAN, Krakow, Poland
N. Marginean et al., IFIN HH, Bucharest, Romania
C. Michelagnoli et al., ILL, Grenoble, France
R. V. F. Janssens et al., University of North Carolina at Chapel Hill, North Carolina, USA
M. Sferrazza, *Universitè libre de...
In the recent years, attention has been paid to a careful measurement of the dipole polarizability and parity violating asymmetry in medium and heavy mass nuclei such as $^{48}$Ca and $^{208}$Pb [1-4]. These two observables, as it already happened for the neutron skin thickness, are thought to be particularly sensitive to the properties of the nuclear equation of state at densities around...
R3B is a scientific collaboration of FAIR working towards the realization of an apparatus, located at the end of the High-Energy Branch of this facility, that will receive exotic isotopes of any chemical element from Hydrogen up to Uranium moving at energies around 1 A GeV. R3B will allow us to explore the limits of the nuclear shell model, to study exotic (barionic and strange) nuclear matter...
Neutron‐deficient nuclei around mass number A~80 are of great interest in nuclear structure and nuclear astrophysics (this region, e.g., is explored in the rp‐process nucleosynthesis). Although shape‐coexistence is becoming a rather common feature along the nuclear chart [1], the region of medium‐mass N~Z nuclei is expected to show several collective structures associated to distinctive shapes...
In April 2022, AGATA, the European Ge-array at the forefront of gamma detection technology [1,2] was installed at LNL. Based on the new concept of gamma-ray tracking, it can identify the gamma interaction points (pulse shape analysis) and reconstruct via software the trajectories of the individual photons (gamma-ray tracking). Shortly thereafter a physics campaign has started using stable...
I shall discuss the meaning of the "nuclear shape" in the laboratory frame proper to the Spherical Shell Model, and the
algebraic models that make its foundations.
Shape coexistence, shape mixing and shape entanglement will be illustrated with relevant physics cases, In particular
I shall show that shape coexistence acts as a portal to the Islands of Inversion at
at N=20-28 and N=40-50...
The dynamics of nuclei with a triaxial core and a non-axial rigid quasiparticle alignment is described in a semiclassical setting [1,2]. This includes the investigation of the spin dependence of the stationary points and the derivation of the existence conditions for distinct dynamical phases. Additionally, an intuitive visualization of the classical orbits is used to show the classical motion...
There is an increasing interest in exotic symmetries predicted to occur in atomic nuclei, yet in the past traditionally associated with molecular structures. This tendency is witnessed by growing number of publications in this domain. Tetrahedral and octahedral symmetries can be considered among the most exotic since they are predicted to produce 4-fold degeneracies of the nucleonic levels in...
Transfer reactions are pivotal in nuclear structure and reaction studies. In heavy-ion transfer reactions, multiple nucleons can be transferred in a single collision along with significant energy and angular momenta from the relative motion to the intrinsic degrees of freedom [1,2]. This establishes multinucleon transfer reactions as an essential tool for probing a wide array of topics, from...
The COLLAPS experiment stands at the forefront of collinear laser spectroscopy, a field dedicated to the precise measurement of unique nuclear characteristics in short-lived and exotic radioactive nuclei. By analyzing hyperfine structures and isotope shifts, it determines nuclear spins, electromagnetic moments, and charge radii.
At its core, COLLAPS seeks to unravel the mysteries surrounding...
Nuclei in the vicinity of doubly-magic nuclei, such as $^{78}$Ni, are of considerable interest for studying the evolution of shell structure within the nuclear shell model. Understanding this evolution is essential for accurately describing exotic nuclear phenomena. In particular, the shape coexistence in $^{79}$Zn makes this region especially intriguing, given that such a phenomenon is...
We study the shape coexistence in the nucleus $^{28}$Si with the nuclear shell model using numerical diagonalizations complemented with variational calculations based on the projected generator-coordinate method. Although the ground-state oblate rotational band is well described in the $sd$ shell by the USDB interaction, the second excited $0^+_3$ state and higher-energy levels lack the...
Neutron-rich nuclei in the A=100 mass region display a large variety of shape coexistence phenomena dominating their structure and dynamics. Multifaceted impact of shape coexistence is revealed in the structural evolution with spin, excitation energy, and neutron number, the appearance of the isomeric states, their exotic decay including allowed and first-forbidden β decay. We studied the...
The astrophysical rapid-neutron capture process (r-process) of explosive nucleosynthesis is responsible
for the formation of half of the heavy nuclei above Fe. Actinides are produced towards
the end of this process, when the neutron flux is expected to be minimal, and it is supported also
by fission processes. Given that the r-process path runs far away from the accessible species, in
this...
Spectroscopic properties of exotic nuclei are powerful tools to obtain a better insight on the evolution of nuclear structure far from the stability. Mid-shell nuclei are expected to exhibit collective behaviour which is typically reflected in the observation of low excitation energies of the first excited states and high transition probabilities. Moreover, the collectivity is expected to...
One of the best-known divergences from the independent-particle shell model description is the existence of islands of inversion [1]. The IoI of the region N=40 draws particular attention since the neutron number 40 was postulated as a non-traditional “magic” number and N = 40 represents the boundary between the negative-parity pf shell and the positive-parity g shell. In stable nuclei,...
In the past ten years, a series of experiments have been done at the HIRFL-RIBLL1 facility for studying the exotic decays of extremely proton-rich nuclei in sd-shell. Beta-delayed proton and two-proton decays from 20;21Mg, 22;23Al, 22;23;24Si, 26;27P, 27;28;29S have been measured by the continuous implantation-decay method using silicon array combined with gamma-ray detectors [1]. With high...
Superheavy nuclei (SHN) with an extremely large number of protons (e.g., up to Z = 126) remain to be one of the main topics in nuclear physics [1]. One of the ultimate goals of this research is to explore the fission-stability of SHN at around Z = 114 − 126 and N = 184, where the next shell closures are predicted to occur [1]. The fission half-lives of those SHN were predicted to be much...
The MNT reaction allows us to produce many fissioning nuclei, including neutron-rich nuclei, which cannot be populated by other reactions. Also, excitation energy of compound nucleus distributes widely. These properties are used to obtain fission-fragment mass distribution (FFMDs) for many nuclides as well as their excitation-energy dependence [1,2,3]. The experiments were carried out at the...
Neutron-rich Ca isotopes towards neutron number N = 34 are pivotal for exploring the evolution of the fp-shell orbitals [1]. Beyond the N = 28 shell gap at 48Ca, new magic numbers at N = 32 and 34 were established through spectroscopy of low-lying states [2] and mass measurements [3]. Most recently, the spatial extension of the 1f7/2 and 2p3/2 neutron orbitals was determined via a one-neutron...
The Coupled Channels (CC) model successfully explained the strong enhancement of sub-barrier fusion cross sections as well as the observed structures in the barrier distributions for many systems. However, there are several mechanisms whose influence on the fusion is still not clear, as the role of weak (non-collective excitations) reaction channels. The experimental barrier distributions of...
Heavy-ion fusion reactions are essential to investigate the fundamental problem of quantum tunnelling of many-body systems in the presence of intrinsic degrees of freedom. Studying the fusion of light systems with Q > 0, and the identification of hindrance [a] requires challenging measurements. The investigation of slightly heavier cases allows a reliable extrapolation towards the lighter...
The dynamics of induced fission is described using a consistent microscopic framework that combines the time-dependent generator coordinate method (TDGCM) and time-dependent nuclear density functional theory (TDDFT). While the former presents a fully quantum mechanical approach that describes the entire fission process as an adiabatic evolution of collective degrees of freedom, the latter...
The physics of neutrinoless double beta (0νββ) 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 0νββ decay half-lives, the knowledge of the Nuclear Matrix Elements (NME) involved in the transition is...
The motivations for studying nuclei far from the valley of stability are manifold: from the study of the role played by the different parts of the nuclear force in the evolution of shell gaps, to the appearance of halo nuclei and clusters in a variety of isotopic chains linked to the proximity of the continuum, including the reordering of the neutron/proton shells as we move toward the...
The significant alteration in the trend of the nuclear charge radius within certain isotopic families, when plotted against the mass number A, is called the kink effect (KE). The most typical example of the KE is found in the charge radii of Pb isotopes. This kink is reasonably well reproduced by the nuclear relativistic mean-field [1-4] and relativistic Hartree-Fock approximations [5], while...
Reaction dynamics induced by proton drip-line nuclei at energies around the Coulomb barrier is one of the most popular topics in nuclear physics. In order to further investigate the reaction mechanisms of proton drip-line nuclei, we performed the complete-kinematics measurements of $^8$B+$^{120}$Sn and $^{17}$F+$^{58}$Ni at CRIB, University of Tokyo. Two detector arrays, i.e., the silicon...
The nuclear chart corresponding to light radioactive nuclei has yielded many surprising results, among others, the discovery of the halo structures in neutron and proton dripline nuclei. This region of the nuclear chart is also rich of many other phenomena like the appearance of molecular-like structures where $\alpha$-particle-clusters are bound together by the exchange of neutrons or the...
Reveling the details of different states in light nuclei and gaining a complete spectroscopic picture of nuclei close to the A=10 is important for many reasons. In this mass region states of dominantly shell model character are mixed with molecular and cluster states, including rather exotic ones, like Borromean (e.g. 9Be) and halo (e.g. 11Be) states, or even Bose-Einstein condensates...
Since the mid-60s, the presence of a 2$^+$ doublet in $^8$Be, constituted by the 16.6 and 16.9 MeV excited states, has been observed [1-3]. An intriguing aspect of this doublet is its status as the best-known instance featuring a complete isospin mixing, where the 16.6 MeV ($^7$Li+p) and 16.9 MeV ($^7$Be+n) levels can be decomposed in an equal mixture of two pure isospin (T=0 and T=1) levels...
3He induced reactions allow to investigate the spectroscopy of high excitation energy regions of light compound nuclei that can be formed in low energy reactions. We performed a new experiment of this type, HELICA, with the solid-state hodoscope OSCAR at the AN-2000 accelerator of the INFN-LNL. In the experiment, a 3He beam, with energies ranging from about 1400 keV to 2200 keV was delivered...
In this talk I will present a comparison between the experimental data and the transport model AMD [1] (Antisymmetrized Molecular Dynamics) coupled with GEMINI++ as afterburner[2] for the reaction $^{18}$O+$^{12}$C at 16.7 MeV/nucleon measured using the GARFIELD+RCo [3] apparatus at LNL.
Considering some recent systematics [4,5], in our system the statistical process are only a small part of...
Among the hydrogen burning processes in stars, proton reactions with Ne isotopes are very relevant to constrain the production and abundances of neon and sodium isotopes in massive stars, novae and supernovae. In particular the 20Ne(p,γ)21Na reaction is the first and slowest reaction of the NeNa cycle and it controls the speed at which the entire cycle proceeds: its rate affects the synthesis ...
Light (e.g. deuterons, tritons, helions, α−particles), and heavy (pasta phases) nuclei exist in nature in core-collapse supernova matter and neutron star (NS) mergers, where temperatures of the order of 50 to 100 MeV may be attained. In the NS inner crust, that is under different conditions of temperature, density and asymmetry, these heavy clusters should also be present. The appearance of...
In this talk, we will present our work at the interface between density functional theory (DFT) and ab initio theory. In particular, we will focus on infinite nuclear matter, that we simulate using a description based on a finite number of nucleons, and discuss three research directions [1]:
1. a new ab initio Self-consistent Green's function (SCGF) approach, based on the algebraic...
On behalf of the COLLAPS collaboration
Over a decade ago, the first experimental evidence for the N=32 sub shell closure in the calcium isotopic chain emerged [1,2]. Subsequent experimental and theoretical investigations have confirmed this finding. However, in laser spectroscopy measurements extending up to $^{52}$Ca (N=32), no indications of this shell gap were apparent [3]. Crossing the...
In-beam γ-ray spectroscopy of 79Cu was carried out at the Radioactive Isotope Beam Factory of the Riken laboratory during the 2021 Hicari campaign [1]. In-flight fission of 238U at 345 MeV/nucleon produced a wide range of exotic nuclei, including 80Zn. These nuclei were sent through the Bigrips separator onto a beryllium target, where knock-out reactions took place. The emitted γ-rays were...
The neutrinoless double beta decay is of fundamental importance for particle physics, nuclear physics, and cosmology. Nuclear matrix element, which encodes the impact of the nuclear structure on the decay half-life, is crucial to interpreting the experimental limits and even more potential future discoveries. However, current knowledge of the nuclear matrix element is not satisfactory due to...
K. J. Abrahams,1 J. N. Orce,1, 2 L. P. Gaffney,3, 4 D. G. Jenkins,5, 1
T. R. Rodríguez,6 N. Bernier,1, ∗ E. H. Akakpo,1, 7 G. de Angelis,8
M. J. G. Borge,4 A. Brown,5 D. T. Doherty,9 P. E. Garrett,10,1 S. Giannopoulos,4
K. Johnston,4 M. Kumar Raju,1, 11 E. J. Mart´ın Montes,1 D. L. Mavela,1
S. Masango,1 C. V. Mehl,1 D. R. Napoli,12 B. S. Nara Singh,13 C. Ngwetsheni,1
S. S. Ntshangase,7 G....
The nuclear structure of 51Ar, an uncharted territory so far, was studied by the (p,2p) reaction using γ-ray spectroscopy for the bound states and the invariant mass method for the unbound states. Two peaks were detected in the γ-ray spectrum and six peaks were observed in the 50Ar + n relative energy spectrum. Comparing the results to our shell-model calculations, two bound and six unbound...
Reactions induced by alpha particles are important in multiple research areas such as nuclear astrophysics, nuclear technologies,dark matter searches and neutrino physics. Accurate data on neutron yields from the interaction of α-particles with nuclei via (α, n) reactions are of particular interest in this context. Despite the existence of experimental data and libraries, they show large...
Recently we have analysed two types of excited states generated from a ground state described by a pair condensate [1].
One type is obtained by breaking a pair from the ground state condensate and replacing it by ”excited” collective pairs built on time-reversed single-particle orbits. The second type is described by a condensate of identical excited pairs. The structure of these excited...
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 power called decay heat[5]. 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...
Several works focused on light isotopes [1,2,3] have shown a reduction of the cross sections with respect to the theoretical predictions for single-nucleon knockout reactions. These studies have reached different conclusions regarding the dependence of the reduction factor observed of the spectroscopic factor with respect to the N/Z of the projectile. The study of (p,pX) knockout reactions...
The term "halo nucleus" was coined to describe nuclei exhibiting an unusually large spatial extension, deviating from the standard formula r=r$_o$⋅A$^{1/3}$. The initial empirical observation of this phenomenon arose from scattering experiments involving, among others, lithium isotopes [1]. These experiments, designed to measure the interaction cross-section of neutron-rich nuclei, revealed a...
The experimental data from quasielastic electron and (anti)neutrino scattering on $^{12}$C are reanalyzed in terms of a new scaling variable $\psi^*$ suggested by the interacting relativistic Fermi gas with scalar and vector interactions, which is known to generate a relativistic effective mass for the interacting nucleons. We construct a new scaling function $f^\text{QE}(\psi^*)$ for the...
Direct reactions are fundamental tools to investigate the structure of exotic nuclei. Stud-
ies of nuclei far away from stability are usually performed with secondary radioactive beams,
that su er from low intensities and need to be compensated with thick targets and high
e cient detection systems to increase luminosity. Active targets are invaluable devices that,
among other important...
A series of sub-barrier transfer experiments have been recently carried out at LNL, with reaction products detected in inverse kinematic and at forward angles with the large solid angle magnetic spectrometer PRISMA. We measured transfer cross sections far below the Coulomb barrier, making excitation functions down to very low energies. At these low energies, corresponding to very large...
Proton-neutron pairing and α-like quartet condensation in N=Z nuclei
Nicolae Sandulescu
National Institute of Physics and Nuclear Engineering, Magurele-Bucarest, Romania
A specific feature of N = Z nuclei is the occurrence of α -like quartet structures, composed by two neutrons and two protons, which have strong internal...
We present a theoretical framework for treating the full excitation spectrum of Jπ = 0+ pair addition modes, including the well-known low-lying and bound Pairing Vibration on par with the predicted Giant Pairing Vibration lying in the continuum [1]. Our formalism includes the coupling to low-energy collective quadrupole modes of the core, in such a way that both single-particle self-energy...
The $^4$He nucleus is one of the simplest nuclear systems. No bound excited states are present in its level scheme however, a pronounced resonance with the same spin and parity (0$^+$) as the ground state exists with a centroid slightly above the proton emission energy threshold. The results from several available studies show discrepancies on the determination of the $^4$He(0$^+_2$) resonance...
Superfluidity and superconductivity are remarkable manifestations of quantum coherence at a macroscopic scale. The existence of superfluidity has been experimentally confirmed in many condensed matter systems, in He-3 and He-4 liquids, in nuclear systems including nuclei and neutron stars, in both fermionic and bosonic cold atoms in traps, and it is also predicted to show up in dense quark...
Isomers close to the doubly magic nucleus 78Ni (Z=28, N=50) provide essential information on the shell evolution and shape coexistence far from stability. We have performed high-precision mass measurements of isomeric states close to 78Ni with the JYFLTRAP double Penning trap mass spectrometer [1] at the Ion Guide Isotope Separator On-Line (IGISOL) facility. The existence of a long-lived...
Exotic light-nuclei with low particle separation energy can exhibit a very extended matter distribution, the so-called nuclear halo [1, 2]. At collision energies around the Coulomb barrier, the presence of a halo enhances the coupling between the elastic and reaction channels, such as breakup, transfer, and fusion, as compared to stable well-bound nuclei. The Coulomb barrier scattering of...
The presence at low energy of pair of nuclear levels differing in orbital angular momentum by two units, which can be ascribed to single-particle states in the shell model, is common place in many odd-mass nuclei located near closed shells. Such single-particle states can be labelled with the radial quantum number n$_r$, the orbital angular momentum $l$ and the total angular momentum $j$, and...
A rigorous few-body scattering theory as proposed by Faddeev and extended by Yakubovsky and Alt, Grassberger and Sandhas is implemented in the momentum-space framework. Past applications include the nucleon-deuteron scattering, three-cluster nuclear reactions, and four-nucleon scattering. Recent and ongoing extensions of this framework will be presented.
First, we made a two-fold extension...
In recent decades, $\gamma$-ray spectroscopy has experienced a significant technological advancement through the technique of $\gamma$-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 $\gamma$-ray spectroscopy. Combining $\gamma$-ray spectrometers with...
PARIS (Photon Array for studies with Radioactive Ion and Stable beams) is an international research project with the aim of developing and building a novel 4π gamma-ray calorimeter, benefiting from recent advances in scintillator technology. It is intended to play the role of an energy-spin spectrometer, a calorimeter for high-energy photons and a medium-resolution gamma-detector. The device...
A systematic study of the isoscalar giant monopole resonance (ISGMR) in a variety of nuclear systems is performed within the microscopic self-consistent Skyrme HF+BCS method and coherent density fluctuation model. The calculations for the incompressibility in finite nuclei are based on several energy density functionals for nuclear matter. This theoretical scheme is successfully proved, for...
The isotopic chains close to the nuclei number $Z$=50 have motivated extensive experimental and theoretical efforts during the last decades. Their structure provide an excellent ground to study shell-evolution along the chain and to investigate the interplay between single-particle and collective degrees of freedom. The systematic study of excited structure of nuclei in the double magic...
Describing the properties of highly excited nuclei or atomic nuclei at finite temperatures remains one of the most challenging tasks for both nuclear theory and experiment. Understanding the response of nuclei, particularly electromagnetic dipole transitions, under extreme conditions is not only crucial for nuclear physics but also essential for modelling astrophysical phenomena such as...
Nuclear giant resonances provide deep insight in understanding the structure of atomic nuclei as well as constraining the nuclear equation of state (EoS). The giant monopole resonance (GMR) and giant dipole resonance (GDR) provide effective constraints on nuclear incompressibility and symmetry energy slope parameter, respectively. The giant quadrupole resonance (GQR) gives useful information...
Astronomical observations indicate that the abundances of heavy elements from barium to lead in metal-poor stars are consistent with the scaled Solar system abundance pattern for the rapid-neutron capture or r-process, where 50% of the heavy elements beyond iron are expected to be produced in stellar explosions such as neutron star mergers. Given that the Sun formed billions of years after...
Systematic studies of nuclear reactions are essential to the development of nuclear physics.
Understanding and predicting the evolution of nuclear structure and the novel phenomena in atomic 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...
Octupole correlations near $N = Z = 56$ are unique in 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 Fermi...
The nuclear structure of neutron-rich nuclei around A ∼ 100 shows shape transitions and large deformations. Among others, these include ellipsoidal oscillation of the shape (γ-vibrations). One-phonon γ-bands are observed in numerous deformed nuclei, however, observations of two or higher-order phonon γ-bands are rare. While the even-Z nuclei have been well investigated, the spectroscopy of...
Recent predictions of reactors $\bar{\nu}$ spectra have revealed two irregularities: the Reactor Antineutrino Anomaly (RAA) and the spectral "bump" [1,2,3]. These predictions, calculated with the Huber-Muller Conversion model [4,5], have provoked several doubts about the integrity of experimental data and the accuracy of the models used. In view of this, improved measurements of nuclear data...
Conventional high-resolution techniques for $\beta$-decay spectroscopy utilize high-purity germanium detectors to measure individual $\gamma$ rays emitted after $\beta$ decay. However, this kind of measurement is affected by the Pandemonium systematic error [1], resulting in many high-energy $\gamma$ rays and a significant portion of the $\beta$ strength being missed. The Total Absorption...
Experimental data of isomerism in the neutron-rich N ≥ 126 region are important to test the predictability of shell evolution beyond the N = 126 shell closure by shell-model calculations. Moreover, the predicted properties of more exotic isotopes could affect the abundance of actinides in r-process calculations [1]. However, these information are scarcely available as it is challenging to...
The nuclear structure of doubly magic nuclei such as $^{100}$Sn and its neighboring isotopes is of significant interest due to the valuable insights it offers for testing the nuclear shell model. However, describing the nearby Cd isotopic chain poses additional challenges due to the enhanced correlations induced by two proton holes in the g9/2 orbit. In particular, $^{98}$Cd (Z=48, N=50)...
The Bohr-Mottelson Hamiltonian [1,2] has been numerically solved for a sextic oscillator potential in the β variable, for both stable and unstable γ-axial deformations [3,4]. The sextic potential, depending on its parameters, presents a single spherical minimum, a flat shape, a single deformed minimum and simultaneously spherical and deformed minima separated by a barrier (maximum) [5,6]....
Shape of nuclei is determined by a fine balance between the stabilizing effect of closed shells and the pairing and quadrupole forces that tend to induce deformation [1]. In the mass region around A=100, there exist clear cut examples of the rapid appearance of deformation such as Zr (even-even) [2] and Nb isotopes (odd-even) [3], which can be understood in terms of the coexistence of two...
Mass spectrometry is invaluable for probing the essential characteristics of nuclei, particularly their binding energy. The FRS Ion Catcher at GSI employs a Multiple-Reflection Time-of-Flight Mass Spectrometer (MR-TOF-MS) to achieve precise, fast, and sensitive mass measurements, crucial for studying exotic nuclei far from stability. Previous investigations, have scrutinized properties of...
The coincidence Doppler-shift attenuation method (CDSAM) is a powerful technique for determining nuclear level lifetimes in the femtosecond regime [1,2].
At the SONIC@HORUS setup [3] at the University of Cologne, several (p,p'$\gamma$)- and ($\alpha$,$\alpha$'$\gamma$)-CDSAM experiments have been performed with a focus on the A $\approx$ 100 mass region, including Zr, Ru, Pd, Sn, and Te...
Nuclei with a large N/Z ratio are of great interest to test nuclear models and provide information about single particle states far off stability. During the last two decades there has been a substantial effort directed to gathering information about the region around the neutron-rich $^{132}$Sn [1-3]. Lifetimes of excited states provide direct access to the reduced transition probabilities...
The nuclear shell model is one of the prime many-body methods to study the structure of atomic nuclei, but it is hampered by an exponential scaling on the basis size as the number of valence particles increases. I will discuss a quantum circuit design strategy to find nuclear ground states by exploiting an adaptive variational quantum eigensolver algorithm. This circuit implementation is in...
AGATA (Advanced Gamma-ray Tracking Array, www.agata.org) is the European forefront instrument for high-resolution γ-ray spectroscopy based on high-purity segmented germanium detectors. Thanks to its fine segmentation, digital data acquisition electronics and pulse-shape analysis techniques, AGATA can track the path of a gamma ray inside the spectrometer to reconstruct its emission angle as...
The lifetimes of nuclear excited states are directly related to electromagnetic transition probabilities
and their determination has strong impacts on our understanding of nuclear structure and of a
variety of astrophysical scenarios.
At the Legnaro National Laboratories of INFN in the last 2 years an extensive experimental
campaign has been carried out with the γ-ray tracking array AGATA [1]...
The investigation of neutron-rich nuclei situated below $^{208}$Pb is anticipated to unveil a spectrum of phenomena, from shape evolution to the existence of exotic shapes and co-existence, which manifest from nuclear interaction. Additionally, nuclides' vicinity to the N=126 shell closure is linked to understanding the r-process path towards actinides. Although its importance is well...
In this talk, we will discuss some aspects of the structure of neutron-rich F nuclei within the framework of the particle plus rotor model. Specifically, the low-lying structure of 25,27,29F can be understood in the rotation-aligned coupling scheme with their 5/2+ ground states as the bandhead of a decoupled band [1,2].
The excitation energies of the 1/2+ and 9/2+ states correlate strongly...
Laser spectroscopy is a powerful tool for studying how structures of ground and isomeric states evolve across the chart of nuclides [1]. By measuring isotope shifts and hyperfine structures we can deduce fundamental properties such as nuclear spins, changes in mean-squared charge radii and electromagnetic moments, all in a model-independent way. Such data are excellent tests for theory,...
In stellar environments nuclei appear at finite temperatures, becoming extremely hot in core-collapse supernovae and neutron star mergers. However, due to theoretical and computational complexity, most model calculations of nuclear properties are performed at zero temperature, while those existing at finite temperatures are limited only to selected regions of the nuclide chart. Recently a...
A novel technique has been developed to measure lifetimes of heavy neutron-rich nuclei, namely 'the reversed plunger'. In heavy neutron-rich nuclei, information on the lifetimes of low-lying excited states is scarce since these nuclei are difficult to populate. Among different reaction mechanisms, multi-nucleon transfer reactions have shown to be the perfect tool to explore such regions....
Recently, some theoretical nuclear structure works have pointed out the relation between the nuclear matrix elements of neutrinoless double-beta decay, a much sought-after nuclear decay that emits two matter particles without antimatter [1,2], and the corresponding matrix elements of double-gamma decay from the double isobaric analog states (DIAS) of the initial double-beta decay nuclei [3,4]....
The Facility for Rare Isotope Beams (FRIB) [1] is a US Department of Energy User facility providing primary, heavy-ion beams with energies up to 300 MeV/u (typically 250 MeV/u for most mid-mass beams). Typical beam intensities are 500 pnA with plans to increase to 20,000 pnA. This capability positions FRIB as a pivotal resource for accessing a broad spectrum of rare isotope beams. Herein, we...
