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Our current knowledge of the Equation of State of asymmetric nuclear matter around saturation density and of the energy of the Isobaric Analog State in a heavy nucleus such as 208Pb seem to be in contradiction. In Ref. [1], the problem has been highlighted and a solution has been proposed. In the present contribution, we overview the aforementioned work by giving some new details not previously published.

Recent results on the structure of 47Ca will be presented. The nucleus of interest was populated via the cold-neutron capture 46Ca(n,γ) reaction, on a rare 46Ca target, during the EXILL experimental campaign at the nuclear reactor of Institut Laue- Langevin in Grenoble. High-resolution γ-ray spectroscopy, performed with a composite array of HPGe detectors, enabled the identification of new transitions deexciting states between the neutron-capture level and the ground state. Experimental data will be compared with a novel microscopic theoretical model, currently under development, specifically designed to describe the low-lying structure of odd-mass nuclei with one valence particle/hole outside a spherical doubly-magic core, using the Skyrme effective interaction self-consistently.

A completely microscopic beyond mean-field approach has been elaborated to overcome some intrinsic limitations of self-consistent mean-field schemes applied to nuclear systems, such as the incapability to produce some properties of single-particle states (e.g. spectroscopic factors), as well as of collective states (e.g. their damping width and their gamma decay to the ground state or to low lying states). Since commonly used effective interactions are fitted at the mean-field level, one should aim at refitting them including the desired beyond mean-field contributions in the refitting procedure. If zero-range interactions are used, divergences arise. We present some steps towards the refitting of Skyrme interactions, for its application in finite nuclei.

In this work, electron-capture rates on nuclei for stellar conditions are calculated for Ni isotopes, using a self-consistent microscopic model based on the finite-temperature Skyrme Hartree-Fock plus finite-temperature charge-exchange random-phase approximation approach. The results of the calculations show that electron-capture rates obtained either with different Skyrme sets or with different available models can differ by up to a few orders of magnitude.

The effects of the tensor force on the charge-exchange Gamow-Teller (GT) and spin-dipole (SD) states are studied by using the self-consistent Hartree-Fock plus Random Phase Approximation (HF+RPA) approach based on Skyrme zero-range forces. We have found, not surprisingly, that the tensor force has a large effect on the GT strength. In the case of the SD excitations, the tensor force produces a softening of the 1− states, but a hardening of 0− and 2− states: these effects improve the agreement with the experimental findings. We have also studied how to constrain the magnitude of the tensor terms of the Skyrme interaction by using the empirical information on the collective GT and SD excited states in 90Zr and 208Pb.

Experimental and theoretical efforts are being devoted to the study of observables that can shed light on the properties of the nuclear symmetry energy. We present our new results on the excitation energy [1] and polarizability of the Isovector Giant Quadrupole Resonance (IVGQR), which has been the object of new experimental investigation[2]. We also present our theoretical analysis on the parity violating asymmetry at the kinematics of the Lead Radius Experiment (PREx [3]) and highlight its relation with the density dependence of the symmetry energy [4].

A completely microscopic formalism has been developed to treat the observable properties of single-particle states (e.g. energies and spectroscopic factors), as well as of collective states (e.g., their energy centroid, their damping width and their gamma decay to the ground state or to low lying states) beyond mean-field. The phonons are calculated within the fully self–consistent random phase approximation (RPA). The particle-vibration coupling (PVC) is accounted for within the framework of the nuclear field theory (NFT) at the lowest contributing order. All the calculations have been performed using the whole effective Skyrme interaction.

Zero–range effective interactions are commonly used in nuclear physics to describe a many-body system in the mean-field framework. If they are employed in beyond-mean-field models, an artificial ultraviolet divergence is generated by the zero-range of the interaction. We analyze this problem in symmetric nuclear matter with the t0 – t3 Skyrme model. In this case, the second-order energy correction diverges linearly with the momentum cutoff Λ. After that, we extend the work to the case of nuclear matter with the full Skyrme interaction. A strong divergence (∼ Λ5) related to the velocity-dependent terms of the interaction is obtained. Moreover, a global fit can be simultaneously performed for both symmetric and nuclear matter with different neutron-to-proton ratios. These results pave the way for applications to finite nuclei in the framework of beyond mean-field theories.

Hallux valgus (HV) is a frequent forefoot deformity affecting about 23% of adults and 35.7% of people over 65. The exact etiology is not fully understood. The first ray plays a significant role in walking cause it bears the principal amount of weight and maintains the position of the medial arch. Several factors that deteriorate the integrality of the first ray, such as foot deformities, restrictive footwear, and pes planus, may be ascribed to the HV occurrence. Before any surgical correction, conservative treatment should always be initiated first. Currently, there is no consensus that conservative management by shoe modification and foot orthoses could correct the pathology or terminate the clinical worsening of the condition. From a careful analysis of the literature, proper footwear should be a shoe with an adequate length, wide toe box, cushioned sole, and a lowered heel to not increase the load on the metatarsal heads and cause pain. Personalized 3D printed customized toe spreaders may be applied in patients with HV, improving symptoms and bringing pain relief. Compensating the subtalar joint hyperpronation through foot orthoses plays a fundamental role in the HV development, preventing or at least controlling the condition's progress; this, along with weight reduction and regular physical activity. Data obtained suggest that dynamic foot orthoses prefer a biomechanical type with 3/4-length, which is less likely to negatively affect the dorsal or medial pressures, which instead were noted to increase with the sulcus- and full-length orthoses. Although some studies suggest that foot orthoses would favor the correction of HV deformity, results have been very variable and just in few studies appear to correct HV or reduce its progression, improving symptoms and bringing pain relief. In the case of HV surgical correction, orthoses seem to maintain the correct position acquired over time. [ABSTRACT FROM AUTHOR]

Background: Minimally invasive surgery (MIS) in medial displacement calcaneus osteotomy (MDCO) has been proposed for surgical correction of adult-acquired flat foot deformity (AAFD) to reduce complications of open approaches. The aim of our study is to systematically analyze complications and the clinical and radiological results of MIS- MDCO. Methods: A systematic review of the English literature was performed on 30th October 2023. Randomized controlled trials and non-randomized trials, cohort studies, case–control studies and case series concerning surgical correction of AAFD with MIS-MDCO and with at least 15 patients were included. Case reports, technical notes, animal or cadaveric studies were excluded. The quality and risk of bias of the studies included were evaluated using GRADE and MINORS systems. Complications rate, clinical and radiological results were inferred from the studies included. Results: Nine articles were included. A total of 501 cases treated with MIS-MDCO were analysed with a mean follow-up of 11.9 ± 5.1 months. The reported wound infection rate was about 3% and sural neuropathy was rated about 1%. Only 4% of the cases required removal of the screw for pain. In the comparative studies (MIS versus Open MDCO), comparable clinical results but with significant differences (P < 0.001) in infection rates (1% versus 14%) and sural neuropathy (2% versus 1%) were observed. Conclusion: AAFD correction performed with MIS-MDCO, with the limitation of a poor quality and high risk of bias of the included studies, seems to provide good clinical results and high subjective satisfaction with a lower complication rate compared to open approach. Further high-quality long-term comparative studies could better clarify complications and clinical and radiological outcomes of the MIS technique in the treatment of AAFD. Level of evidence: Level IV. [ABSTRACT FROM AUTHOR]

Brachymetatarsia (BM), or hypoplastic metatarsal, is an abnormal shortening of one or more metatarsal bones with a female-to-male ratio of 10.53:1. Different causes are described in the literature, such as congenital, acquired, or iatrogenic, associated with different conditions and syndromes. Its presence may develop deformity and pain; however, often feet are pain free and the major worries of patients are cosmetics. Non-operative treatments aim to improve the comfort of metatarsal heads and the possible dorsal conflict through comfortable shoes or the use of specific orthotics. The surgical treatment is anything but straightforward, with "one-stage" or "two stage" techniques, the latter better called "by gradual distraction". One-stage procedures are more rapid techniques but have limited ability to restore the desired length due to neurovascular compromise caused by acute lengthening. Insufficient correction is also possible. On the contrary, by gradual distraction procedures allow gradual distraction lengthening of more than 1.5 cm, but require the use of an external fixator, with a higher risk of complications in more than about 50% of surgeries. The adjacent metatarsal shortening should be considered in combination with other techniques, to diminish the excessive lengthening. In each case, surgeries should be always decided on each patient's concerns, deformities, and clinical needs. [ABSTRACT FROM AUTHOR]

The sacroiliac joint (SIJ) is a possible source of persistent or new onset pain after lumbar or lumbosacral fusion. The aim of this paper is to systematically review and analyze the available literature related to the incidence, diagnosis and management of sacroiliitis after spinal arthrodesis. The authors independently screened the titles and abstracts of all articles identified concerning sacroiliac joint pain after lumbar or lumbosacral fusion, to assess their suitability to the research focus. The average incidence of sacroiliitis after lumbar or lumbosacral arthrodesis was found to be 37 ± 28.48 (range 6-75), increasing directly to the number of fused segments involved, especially when the sacrum is included. The most accurate evaluation is the image-guided injection of anesthetic solutions in the joint. Surgery treatment may be considered when conservative therapy fails, with open surgery or with minimally invasive SIJ fusion. Although the risk of developing SIJ degeneration is unclear, the results indicate that pain and degeneration of SIJ develop more often in patients undergoing lumbosacral fusion regardless of the number of melting segments. The treatment of sacroiliitis appears to be independent of his etiology, with or without previous instrumentation on several levels. [ABSTRACT FROM AUTHOR]

The Gamow–Teller strength distributions of 116 Sb and 122 Sb were measured with the 116 , 122 Sn (3 He , t) 116 , 122 Sb charge-exchange reactions at 140 MeV/u . The measurements were carried out at the Research Center for Nuclear Physics (RCNP) at Osaka University in Osaka, Japan using the Grand Raiden spectrometer. The data were analysed by Multipole-Decomposition Analysis (MDA). The Gamow–Teller strengths summed up to 28 MeV are (38 ± 7) % and (48 ± 6) % of the Ikeda sum rule for 116 Sb and 122 Sb , respectively, if the quasi-free scattering (QFS) contribution is not subtracted. These percentages are (29 ± 7) % and (35 ± 5) % , respectively, if the QFS contribution is maximally subtracted. These results were compared to those from previous measurements of the same isotopes, to recent measurements of 150 Pm , and to a Quasi-particle Random-Phase Approximation (QRPA) calculation with Quasi-Particle Vibration Coupling (QPVC). The data suggest that the true QFS contribution is small for 116 Sb , but are inconclusive about whether the QFS contribution is small or significant for 122 Sb . Therefore, these data may provide an interesting test for the general quenching phenomenon of the Gamow–Teller Resonance (GTR). However, more research to reveal the nature of the QFS contribution is still needed on both the experimental and the theoretical side. [ABSTRACT FROM AUTHOR]

The structure of the 131Sn nucleus was studied at the Institut Laue-Langevin by prompt-delayed -ray spectroscopy across the 0.3 μs, 23/2-isomeric state at 4670 keV, following cold-neutron-induced fission of 235U and 241Pu targets. New -ray transitions are observed and the results are compared with theoretical calculations performed with the Hybrid Configuration Mixing Model. The latter suggests that the majority of the states can be well-described in terms of couplings between single-hole degrees of freedom and 132Sn core excitations, pointing to a robust neutron shell closure at N = 82. [ABSTRACT FROM AUTHOR]

The γ decay of the one-proton valence nucleus 133Sb is studied using the cold-neutron induced fission of 235U and 241Pu targets. The experiment is performed at the ILL reactor in Grenoble, using a highly efficient HPGe array, also coupled to fast LaBr3(Ce) scintillators. High-spin excited states above the 16.6 μs isomer are observed, and the lifetime of the 13/2+ and 15/2+ states is measured by fast-timing techniques, revealing a complex nature of the wave functions. The experimental results are well-interpreted by a newly developed microscopic model which takes into account the coupling between the valence proton and excitations (both collective and noncollective) of the doubly magic 132Sn core. [ABSTRACT FROM AUTHOR]

In this contribution, we review some works related with the extraction of the symmetry energy parameters from isovector nuclear excitations, like the giant resonances. Then, we move to the general issue of how to assess whether correlations between a parameter of the nuclear equation of state and a nuclear observable are robust or not. To this aim, we introduce the covariance analysis and we discuss some counter-intuitive, yet enlightening, results from it. [ABSTRACT FROM AUTHOR]

The scope of the paper is to apply a state-of-the-art beyond mean-field model to the description of the Gamow-Teller response in atomic nuclei. This topic recently attracted considerable renewed interest, due, in particular, to the possibility of performing experiments in unstable nuclei. We study the cases of 48Ca,78Ni,132Sn, and 208Pb. Our model is based on a fully self-consistent Skyrme Hartree-Fock plus random phase approximation. The same Skyrme interaction is used to calculate the coupling between particles and vibrations, which leads to the mixing of the Gamow-Teller resonance with a set of doorway states and to its fragmentation. We compare our results with available experimental data. The microscopic coupling mechanism is also discussed in some detail. [ABSTRACT FROM AUTHOR]

The properties of single-particle states in the magic nuclei 40Ca and 208Pb, in particular the energies, spectroscopic factors, and the effective mass, have been studied in a fully self-consistent particle-vibration coupling (PVC) approach within the framework of Skyrme energy density functional theory. All selected phonons are obtained by the random phase approximation, and the same Skyrme interaction is also used in the PVC vertex. We focus on the effect of the noncentral two-body spin-orbit and tensor interactions on the single-particle properties. It has been found that the contributions of those terms are important to improve the results for 208Pb. The calculated single-particle energies and spectroscopic factors are compared to available experimental data. The single-particle level density around the Fermi surface is significantly increased due to the effect of PVC. [ABSTRACT FROM AUTHOR]

A new theoretical framework has been established and applied in the calculation of electron capture (EC) and β-decay rates in stellar environment, characterized by high density and temperature. For the description of the nuclear properties, the finite-temperature Hartree Bardeen-Cooper-Schrie_er (FTHBCS) theory based on the relativistic derivative-coupling D3C* interaction is employed. In order to describe the charge-exchange transitions, the finitetemperature proton-neutron quasi-particle random-phase approximation is developed (FT-PNRQRPA) which includes both temperature and pairing correlations. In the FT-HBCS calculations, only the isovector pairing is included, while in the residual interaction of the FT-PNRQRPA both the isovector and isoscalar pairing contribute. In this work, results for EC and β-decay rates are presented in the temperature interval T = 0–1.5 MeV and stellar density ρYe = 107 and 109 g/cm3. Both allowed 0+, 1+ and first-forbidden transitions 0−, 1− and 2− are included in the calculations. It is shown that interplay between pairing correlations and finite-temperature effects can lead to significant changes in rates. It is also important to include de-excitations, i.e. transitions with negative Q-value, that become increasingly significant at higher temperatures especially for p f -shell nuclei.

Although many random-phase approximation (RPA) calculations of the Gamow-Teller (GT) response exist, this is not the case for calculations going beyond the mean-field approximation. We apply a consistent model, that includes the coupling of the GT resonance to low-lying vibrations, to nuclei of the fp shell. Among other motivations, our goal is to see if the particle-vibration coupling can redistribute the low-lying GT+ strength that is relevant for electron-capture processes in core-collapse supernova. We conclude that the lowering and fragmentation of that strength are consistent with the experimental findings and validate our model. However, the particle-vibration coupling cannot account for the quenching of the total value of the low-lying strength. [ABSTRACT FROM AUTHOR]

Self-consistent theory frameworks have been introduced for description of excitations in nuclei at finite temperature, based on energy density functionals formulated using i) relativistic mean field Lagrangian with density dependent meson-nucleon vertex functions, and ii) Skyrme-type functionals. Finite temperature random phase approximation (FTRPA) has been employed in description of multipole excitations and charge-exchange modes. It is shown that in the temperature range T = 1–2 MeV additional transition strength appears at low energies due to thermal unblocking of single-particle orbitals close to the Fermi level. Within the finite temperature Hartree-Fock+RPA based on Skyrme functionals, the electron capture cross sections have been studied for target nuclei at temperatures relevant in modeling the supernova evolution. [ABSTRACT FROM AUTHOR]

Most of the Skyrme interactions are known to predict spin or isospin instabilities beyond the saturation density of nuclear matter which contradict predictions based on realistic interactions. A modification of the standard Skyrme interaction is proposed so that the ferromagnetic instability is removed. The new terms are density dependent and modify only the spin p-h interaction in the case of spin-saturated system. We have shown that these new terms change the total binding energy of odd-nuclei by only few tenths of keV. From the analysis of the spin instabilities of nuclear matter, restrictions on the parameters governing the spin-density dependent terms are evaluated. We conclude that with the extended Skyrme interaction, the Landau parameters G0 and $G_0^\prime$ could be tuned with a large flexibility without changing the ground-state properties in nuclei and in nuclear matter. [ABSTRACT FROM AUTHOR]

The nuclear structure community is striving to determine a nuclear energy functional which is as universal and as accurate as possible. When a functional is determined by fitting free parameters, the constraints on these parameters coming from excited states (like the well-known giant resonances) are not, as a rule, imposed. This work shows that at least three constraints could be imposed on Skyrme functionals, by explaining the physical background and discussing their relevance. [ABSTRACT FROM AUTHOR]

In the present contribution, we discuss the relevance of fully self-consistent HF plus RPA (or HF-BCS plus QRPA) calculations based on Skyrme effective forces, and their impact on our present knowledge of basic properties of the nuclear equation of state, like the incompressibilty and the symmetry energy. Finally, we address the problem whether correlations beyond mean field can alter the picture obtained at the (Q)RPA level. Throghout the paper, the comparison with the results obtained using Gogny forces, or RMF Lagrangians, will be emphasized. [Copyright &y& Elsevier]

Abstract: We study the role of the tensor term of the Skyrme effective interactions on the spin–orbit splittings in the isotones and isotopes. The different role of the triplet-even and triplet-odd tensor forces is pointed out by analyzing the spin–orbit splittings in these nuclei. The experimental isospin dependence of these splittings cannot be described by Hartree–Fock calculations employing the usual Skyrme parametrizations, but is very well accounted for when the tensor interaction is introduced. The capability of the Skyrme forces to reproduce binding energies and charge radii in heavy nuclei is not destroyed by the introduction of the tensor term. Finally, we also discuss the effect of the tensor force on the centroid of the Gamow–Teller states. [Copyright &y& Elsevier]