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The present paper is the second of a series of publications that aim at investigating relevant directions to turn the nuclear energy density functional (EDF) method as an effective field theory (EFT). The EDF approach has known numerous successes in nuclear theory over the past decades [1] and is currently the only microscopic technique that can be applied to all atomic nuclei. However, the phenomenological character of the EDF method also comes with important limitations, such as the lack of an explicit connection with quantum chromodynamics (QCD). As was argued in the first paper of this series [2], reformulating the EDF framework as an EFT would enable us to overcome these limitations. In particular, path-integral (PI) techniques are suited to achieve such a purpose as they allow us to design numerous non-perturbative approximations and can take Lagrangians possibly derived from EFTs of QCD as inputs. In our previous paper [2], we have illustrated such technical features for diagrammatic PI techniques in a study of the (0+0)-D O(N)-symmetric φ 4 -theory. In the present work, we consider another class of PI techniques, i.e. functional renormalization group (FRG) approaches, that we apply to the same toy model. Despite our explicit interest for the nuclear many-body problem, the presented study is also directed towards FRG practitioners from various fields: technical details are provided for FRG techniques based on 1-particle-irreducible (1PI), 2-particle-irreducible (2PI) and 2-particle-point-irreducible (2PPI) effective actions, coined respectively as 1PI-, 2PI- and 2PPI-FRGs, and the treatment of the O(N) symmetry is also addressed thoroughly. Connections between these various FRG methods are identified as well. [ABSTRACT FROM AUTHOR]

We present the second part of the paper series devoted to the study of the multi-loop effective potential evolution (or anomalous dimension) in φ 4 -theory using the conformal symmetry. In this paper, we demonstrate that the conformal symmetry can still be useful for the effective potential approach even in the presence of the mass parameter. To this goal, it is necessary to introduce the special treatment of the mass terms as a sort of interaction in an asymptotical expansion of the generating functional. The introduced vacuum V z , x -operation is the main tool to the algebraic scheme of anomalous dimension calculations. It is shown that the vacuum V z , x -operation transforms the given Green functions to the corresponding vacuum integrations which generate the effective potential. [ABSTRACT FROM AUTHOR]

The AGATA tracking detector array represents a significant improvement over previous Compton suppressed arrays. The construction of AGATA led to numerous technological breakthroughs in order to meet the requirements and the challenges of building a mobile detector across Europe. This paper focuses on the design and implementation of the data acquisition system responsible of the readout and control of the germanium detectors of AGATA. Our system is highly versatile, capable of instrumenting AGATA and seamlessly adapting it to various configurations with a wide range of ancillary detectors and/or spectrometers. It consists of three main components: an autonomous and independent infrastructure, a dedicated application core ensuring overall consistency, and a high-performance software package providing a fully integrated data flow management including the setting-up, the supervision and the slow control of the instrument. In this paper, we present a comprehensive analysis of the system's design and performance, particularly under high-counting rate conditions. [ABSTRACT FROM AUTHOR]

Asymptotic normalization coefficients (ANC) determine the overall normalization of cross sections of peripheral radiative capture reactions. In a recent paper [Blokhintsev et al., Eur. Phys. J. A 58, 257 (2022)], we considered the ANC C 0 for the virtual decay 16 O (0 + ; 6.05 MeV) → α + 12 C(g.s.). In the present paper, which can be regarded as a continuation of the previous, we treat the ANCs C l for the vertices 16 O (J π) → α + 12 C(g.s.) corresponding to the other three bound excited states of 16 O ( J π = 3 - , 2 + , 1 - , l = J ). ANCs C l ( l = 3 , 2 , 1 ) are found by analytic continuation in energy of the α 12 C l-wave partial scattering amplitudes, known from the phase-shift analysis of experimental data, to the pole corresponding to the 16 O bound state and lying in the unphysical region of negative energies. To determine C l , the scattering data are approximated by the sum of polynomials in energy in the physical region and then extrapolated to the pole. For a more reliable determination of the ANCs, various forms of functions expressed in terms of phase shifts were used in analytical approximation and subsequent extrapolation. [ABSTRACT FROM AUTHOR]

The even-odd staggering in fission fragments yield distributions is an important observable to address the role of intrinsic excitations in the fission process. However, its computation as a function of the fragment split is an ill-posed problem that is usually solved through certain assumptions. Arguably, the most widely used method for its computation is the log-third-difference method, which assumes an underlying local Gaussian distribution. Experimental data of the even-odd effect show sharp features and peaks that are a challenge for the log-third difference method (or any method for that matter). This paper presents a detailed study of the performance of the log-third-difference method and describes three strategies for improving the precision and accuracy around these sharp features. The best results are obtained with an iterative application of the method and with the use of a multi-Gaussian fit. A hybrid process combining both corrections is also described and applied to real data. In regions with a smooth behaviour, the direct application of the log-third-difference method remains the best option. [ABSTRACT FROM AUTHOR]

In 1981 Icko Iben Jr published a paper entitled “The carbon star mystery: why do the low mass ones become such, and where have all the high mass ones gone?”, where he discussed the discrepancy between the theoretical expectation and its observational counterpart about the luminosity function of AGB carbon stars. After more than 40 years, our understanding of this longstanding problem is greatly improved, also thanks to more refined stellar models and a growing amount of observational constraints. In this paper we review the state of the art of these studies and we briefly illustrate the future perspectives. [ABSTRACT FROM AUTHOR]

Optical model or coupled-channels calculation serves as an entrance to sophisticated calculation of nuclear data. It gives the optical quantities such as total, shape elastic scattering, absorption cross sections, direct inelastic scattering cross sections, angular distributions of elastic and inelastic scattering, and transmission coefficients for subsequent statistical model calculations. Traditionally, coupling of the elastic scattering channel to excited states of the target nucleus was ignored or treated with a simplified model such as rigid rotor or harmonic oscillator. It was a great contribution of Dr. Efrem Sh. Soukhovitsukii who has developed an excellent computation scheme which takes account of the low-lying collective nuclear structure in terms of the soft-rotator + vibrational model, and integrated it into the coupled-channels calculation. This methodology was realized as 2 computer codes, SHEMMAN and OPTMAN. In Japan, we had a fortuitous experience with him to employ this methodology in nuclear data evaluation, which started as a nuclear physics work to analyze neutron-scattering cross section of 12 C which were published as a series of 3 papers in Nuclear Physics A journal. After recognizing the usefulness of this methodology, it was applied to evaluation of nuclear data gradually and extensively, which resulted in obtaining awards of Atomic Energy Society of Japan (AESJ) by one of the authors (SK). This paper describes our collaborative works and recent findings on light-nuclei based on what he had developed. [ABSTRACT FROM AUTHOR]

The mean transverse momentum of produced particles, [ p T ] , and its event-by-event fluctuations give direct access to the initial conditions of ultra-relativistic heavy-ion collisions and help probe the colliding nuclei's structure. The [ p T ] fluctuations can be studied via multi-particle p T correlations; so far, only the lowest four orders have been studied. Higher-order fluctuations can provide stronger constraints on the initial conditions and improved sensitivity to the detailed nuclear structure; however, their direct implementation can be challenging and is still lacking. In this paper, we apply a generic recursive algorithm for the genuine multi-particle p T correlations, which enables the accurate study of higher-order [ p T ] fluctuations without heavy computational cost for the first time. With this algorithm, we will examine the power of multi-particle p T correlations through Monte Carlo model studies with different nuclear structures. The impact on the nuclear structure studies, including the nuclear deformation and triaxial structure, will be discussed. These results demonstrate the usefulness of multi-particle p T correlations for studying nuclear structure in high-energy nuclei collisions at RHIC and the LHC, which could serve as a complementary tool to existing low-energy nuclear structure studies. [ABSTRACT FROM AUTHOR]

In this paper we analyze the relativistic corrections to the leading order three-nucleon (3N) contact interactions. These boost corrections are derived first from the nonrelativistic reduction of covariant Lagrangians and later from the Poincaré algebra constraints on nonrelativistic theories. We show that in order to describe the 3N potential in reference frames other than the center-of-mass frame, the inclusion of five additional terms with fixed coefficients is required. These terms will be relevant in systems with mass number A > 3 . How they will affect EFT calculations of binding energies and scattering observables in these systems should be investigated. [ABSTRACT FROM AUTHOR]

The use of heavy actinide targets, including 243Am, 240,242,244Pu, 245,248Cm, 249Bk, and 249Cf, irradiated by intense heavy ion beams of 48Ca has resulted in a significant expansion of the periodic table since 2000, including the discovery of five new heaviest elements and more than 50 new isotopes. These actinide materials can only be produced by intense neutron irradiation in very high flux reactors followed by chemical processing and purification in specialized hot cell facilities available in only a few locations worldwide. This paper reviews the reactor production of heavy actinides, the recovery and chemical separation of actinide materials, and the preparation of actinide targets for superheavy element experiments. The focus is on 248Cm, 249Bk, mixed 249−251Cf, and 254Es, including current availabilities and new production processes. The impacts of new facilities, including the Superheavy Element Factory at Dubna, accelerator and separator upgrades at RIKEN, and proposed upgrades to the High Flux Isotope Reactor at Oak Ridge are also described. Examples of recent superheavy element research are discussed as well as future opportunities for superheavy research using actinide targets. [ABSTRACT FROM AUTHOR]

Giant Resonances are, with nuclear rotations, the most evident expression of collectivity in finite nuclei. These two categories of excitations, however, are traditionally described within different formal schemes, such that vibrational and rotational degrees of freedom are separately treated and coupling effects between those are often neglected. The present work puts forward an approach aiming at a consistent treatment of vibrations and rotations. Specifically, this paper is the last in a series of four dedicated to the investigation of the giant monopole resonance in doubly open-shell nuclei via the ab initio Projected Generator Coordinate Method (PGCM). The present focus is on the treatment and impact of angular momentum restoration within such calculations. The PGCM being based on the use of deformed mean-field states, the angular-momentum restoration is performed when solving the secular equation to extract vibrational excitations. In this context, it is shown that performing the angular momentum restoration only after solving the secular equation contaminates the monopole response with an unphysical coupling to the rotational motion, as was also shown recently for (quasi-particle) random phase approximation calculations based on a deformed reference state. Eventually, the present work based on the PGCM confirms that an a priori angular momentum restoration is necessary to handle consistently both collective motions at the same time. This further pleads in favor of implementing the full-fledged projected (quasi-particle) random phase approximation in the future. [ABSTRACT FROM AUTHOR]

The paper presents a first comprehensive measurement of the total fission gamma spectrum (TFGS) of 252Cf(s.f.) spanning an energy range from 0.2 to 14.3 MeV using stilbene scintillator spectroscopy. The measurement was performed with the 252Cf(s.f.) source placed in a flexo-rabbit ending, with a stilbene detector located at a distance of 100 cm from the source. The room effect was determined by separate measurement with a 50 cm long lead shielding cylinder placed between the source and the detector. The obtained spectrum was corrected for the effect of the 252Cf source structural parts and the flexo-rabbit ending, using correction function obtained by simulation with the MCNP6.2 code. The main benefit of this independent measurement is the wide energy range, from 0.2 up to 14.3 MeV, in a single experiment, whereas existing measurements typically cover narrower intervals. The knowledge of the TFGS is crucial for various applications involving 252Cf(s.f.) sources, including the design and analysis of nuclear systems, the validation of nuclear data, and the estimation of radiation in the nuclear medicine. The comparison of TFGS with the recently evaluated 252Cf(s.f.) prompt fission gamma spectrum (PFGS) indicates that delayed gammas may contribute above 2 MeV up to the highest energies; the current assumption was that delayed gammas contribution above 2 MeV was negligible. [ABSTRACT FROM AUTHOR]

Super Rosenbluth experiments, elastic electron-proton scattering experiments that eschew traditional electron detection and opt instead for the detection of the recoiling proton, have several experimental advantages. One claimed advantage is that radiative corrections are more favorable, i.e., smaller and with less kinematic dependence. In this paper, we explore this claim by conducting Monte Carlo simulations of both Super Rosenbluth and traditional Rosenbluth experiments with different models of radiative effects. When using a model that employs the peaking approximation, we indeed confirm the reduced kinematic dependence of the radiative corrections. However, we find that more sophisticated models that avoid the peaking approximation are unable to produce numerically stable results, due to a large enhancement to the cross section for bremsstrahlung radiation from the proton when the momentum transfer, Q 2 , approaches zero. Since this enhancement is not modelled in the peaking approximation, a more robust approach to radiative corrections in Super Rosenbluth experiments is needed. [ABSTRACT FROM AUTHOR]

Plasma Wakefield Acceleration (PWFA) is a highly promising method that can reduce the scale and cost of future electron–positron collider experiments. While significant breakthroughs have been achieved in electron acceleration both theoretically and experimentally, generating high-quality positron beams in plasma presents greater challenges. This paper reviews advanced positron acceleration schemes, including particle beam-driven wakefield acceleration, laser-driven wakefield acceleration, radiation acceleration, and hollow plasma channel acceleration. The hollow plasma channel scheme is a promising method that can provide stable and efficient acceleration of positrons, making it more advantageous for experimental implementation. [ABSTRACT FROM AUTHOR]

Structure functions of the spin-1 deuteron will be investigated experimentally from the late 2020’s at various facilities such as Thomas Jefferson National Accelerator Facility, Fermi National Accelerator Laboratory, nuclotron-based ion collider facility, and electron-ion colliders. We expect that a new high-energy spin-physics field could be created by these projects. In this paper, the current theoretical status is explained for the structure functions of spin-1 hadrons, especially on parton distribution functions, transverse-momentum dependent parton distributions, and fragmentation functions. Related multiparton distribution functions are also shown. [ABSTRACT FROM AUTHOR]

Large inconsistencies still exist in nuclear data libraries regarding the kinetic parameters of delayed neutron (DN) precursors. As an example, there is a 17% gap between ENDF-B/VIII.0 and JEFF-3.3 on the average lifetime T1/2 of DN precursors from thermal fission of 235U. This parameter is of major importance for reactivity predictions of nuclear reactors in nominal or accidental configurations. In this context, CEA is actively participating to the ALDEN project (Average number and Lifetime of DElayed Neutrons) which aims at providing the nuclear data community with new data sets of DN from thermal and fast neutron induced fission of various actinides. A dedicated experimental setup was designed and optimized for that purpose and is presented in this paper. It consists of a “long counter” detector containing 16 proportional counters filled with 3He, embedded in a high density polyethylene matrix. The detector surrounds a fissile target prepared in the form of a miniature fission chamber, containing a few hundreds of micro-grams of fissile material. This set-up is connected to fast and efficient neutron shutters that can produce step-irradiations of variable durations. The equations driving the DN counting following step-irradiations of the fissile target are established and discussed in the perspective of DN yield or group parameter measurement. A comprehensive analysis of the different steps of data reduction is detailed: dead time characterization, Region of Interest (ROI) determination, absolute and relative efficiency calibration, fission rate estimation, irradiation time and background determination, DN decay curve production and physical parameter fitting. Following a prototype experiment performed in 2018 at the PF1b cold neutron beam line of Institute Laue Langevin (ILL, Grenoble, France), we discuss here the analysis of two campaigns occurring in 2019 and 2021 in which significant improvements were achieved in terms of background minimization, counting statistics and fission rate determination. The achievements of this work are the measurement of the delayed neutron emission per fission for the thermal neutron induced fission of 235U, estimated at (1.625 ± 0.010) % and the group parameters leading to an estimated lifetime of T 1 / 2 = (8.87 ± 0.10) s. Those results are consistent with the values recommended by the IAEA/CRP work and they come with reduced uncertainties compared with previously published results. [ABSTRACT FROM AUTHOR]

Lattice studies suggest that at zero baryon chemical potential and increasing temperature there are three characteristic regimes in QCD that are connected by smooth analytical crossovers: a hadron gas regime at T < T ch ∼ 155 MeV, an intermediate regime, called stringy fluid, at T ch < T < ∼ 3 T ch , and a quark-gluon plasma regime at higher temperatures. These regimes have been interpreted to reflect different approximate symmetries and effective degrees of freedom. In the hadron gas the effective degrees of freedom are hadrons and the approximate chiral symmetry of QCD is spontaneously broken. The intermediate regime has been interpreted as lacking spontaneous chiral symmetry breaking along with the emergence of new approximate symmetry, chiral spin symmetry, that is not a symmetry of the Dirac Lagrangian, but is a symmetry of the confining part of the QCD Lagrangian. While the high temperature regime is the usual quark-gluon plasma which is often considered to reflect “deconfinement” in some way. This paper explores the behavior of these regimes of QCD as the number of colors in the theory, N c , gets large. In the large N c limit the theory is center-symmetric and notions of confinement and deconfinement are unambiguous. The energy density is O (N c 0) in the meson gas, O (N c 1) in the intermediate regime and O (N c 2) in the quark-gluon plasma regime. In the large N c limit these regimes may become distinct phases separated by first order phase transitions. The intermediate phase has the peculiar feature that glueballs should exist and have properties that are unchanged from what is seen in the vacuum (up to 1 / N c corrections), while the ordinary dilute gas of mesons with broken chiral symmetry disappears and approximate chiral spin symmetry should emerge. [ABSTRACT FROM AUTHOR]

Recently, a hadronic state, named T c s ¯ 0 (2900) + + , about 2.92 GeV with J P = 0 + was observed in LHCb experiment. It is the first observation of a doubly charged open-charm tetraquark with minimal quark constant [ c s ¯ u d ¯ ] , and hence has a peculiar importance. In this paper, we examine the diquark-antidiquark interpretation for the structure of T c s ¯ 0 (2900) + + in the configurations of [ 3 c ] s ¯ d ¯ ⊗ [ 3 ¯ c ] cu in the framework of QCD sum rules up to dimension 8 condensate in the operator product expansion. Numerical results indicated that the observed T c s ¯ 0 (2900) + + could be embedded into the [ 3 c ] s ¯ d ¯ ⊗ [ 3 ¯ c ] cu configuration. Furthermore, another doubly charged open-charm tetraquark in diquark-antidiquark configuration with mass about 3.13 GeV is also predicted, which are hopefully measurable in BESIII, BEllEII, and LHCb experiments. [ABSTRACT FROM AUTHOR]

Several refined prompt emission model codes, nowadays employed, use the partition of total excitation energy (TXE) according to the temperature ratio RT = TL/TH of fully accelerated fragments. In such codes RT is given as input, either as an unique value for all fragmentations or as a function of AH; This temperature ratio RT being obtained by fitting the experimental ν(A) data with the respective prompt emission model code. This paper proposes a method for obtaining “experimental RT(AH)” (also based on experimental ν(A)), but without resorting to prompt emission model calculations for the fit of ν(A) data. So that this is an independent method providing RT(AH) which can be employed by any prompt emission model code in which the TXE partition is done at the full acceleration according to RT given as input. A procedure which facilitates the parameterization of RT(AH) is proposed, too. A prediction of the RT(AH) shape at very high excitation energies of the fissioning nucleus is also reported. The comparison of RT(AH) ratios obtained from any TXE partition based on modeling at scission with those provided by the present method can constitute a supplementary validation of the respective modeling at scission. [ABSTRACT FROM AUTHOR]

Neutral atom technology has steadily demonstrated significant theoretical and experimental advancements, positioning itself as a front-runner platform for running quantum algorithms. One unique advantage of this technology lies in the ability to reconfigure the geometry of the qubit register, from shot to shot. This unique feature makes possible the native embedding of graph-structured problems at the hardware level, with profound consequences for the resolution of complex optimization and machine learning tasks. By driving qubits, one can generate processed quantum states which retain graph complex properties. These states can then be leveraged to offer direct solutions to problems or as resources in hybrid quantum-classical schemes. In this paper, we review the advancements in quantum algorithms for graph problems running on neutral atom Quantum Processing Units (QPUs), and discuss recently introduced embedding and problem-solving techniques. In addition, we clarify ongoing advancements in hardware, with an emphasis on enhancing the scalability, controllability and computation repetition rate of neutral atom QPUs. [ABSTRACT FROM AUTHOR]

This is a paper on the remarkable evolution in the career of Franz Käppeler that started with the measurements of neutron cross sections of various materials, followed by studies of key nuclei for the slow neutron capture process (s-process) in search of the origins of half of the heavy elements, and eventually to the measurements of the lifetimes of long-lived isomers identified in nuclei along the branching points of the s-process. This evolution of scientific interest took place over 4–5 decades and included the development of new tools and techniques that were implemented into the construction of new facilities for nuclear physics coupled with advances in both astronomical observations and theoretical approaches in modeling. Franz Käppeler led an exemplary life in his love of Rosel, good friends, great champagne, and those ever-elusive neutrons and their interactions with nuclei resulting in the various wonders of the universe. [ABSTRACT FROM AUTHOR]

Analogous to the well-known proton charge radius puzzle, a similar puzzle exists for the deuteron charge radius, r d . There are discrepancies observed in the results of r d , measured from electron-deuteron ( e - d ) scattering experiments, as well as from atomic spectroscopy. In order to help resolve the charge radius puzzle of the deuteron, the PRad collaboration at Jefferson Lab has proposed an experiment for measuring r d , named DRad. This experiment is designed to measure the unpolarized elastic e - d scattering cross section in a low- Q 2 region. To extract the cross section with a high precision, having reliable knowledge of QED radiative corrections is important. In this paper, we present complete numerical calculations of the lowest-order radiative corrections in e - d scattering for the DRad kinematics. The calculations have been performed within a covariant formalism and beyond the ultra-relativistic approximation ( m e 2 ≪ Q 2 ). Besides, we present a systematic uncertainty on r d arising from higher-order radiative corrections, estimated based on our cross-section results. [ABSTRACT FROM AUTHOR]

Usually, the transverse momentum distribution is described by a sum of an exponential decay term plus a decreasing power like contribution representing the soft non-perturbative and hard perturbative QCD collisions, respectively. In this paper, we derive an analytical function that can describe the whole transverse momentum spectrum. This is obtained using a q-Gaussian distribution to describe the string tension fluctuations. The parameter q determines the departure of the thermal distribution as well as the minimum length that can be explored at high transverse momentum. We also show that the ratio between both scales only depends on the q parameter. [ABSTRACT FROM AUTHOR]

In this paper we discuss the combined effects on nuclear matter properties of the quark confinement mechanism in nucleon and of the chiral effective potential resulting from the spontaneous breaking of the chiral symmetry in nuclear matter. One specific aim is to show that the replacement of a basic chiral potential (linear sigma model type) by the enriched Nambu–Jona-Lasinio (NJL) model potential is able to reproduce the saturation properties while strongly decreasing the tension with QCD properties. Based on this NJL prediction, it is shown that the chiral potential acquires a specific scalar field cubic dependence, which contributes to the three-body interaction. We also discuss the constraints induced by Lattice-QCD on the model parameters governing the saturation properties. We introduce the term "QCD-connected parameters" for these quantities. We demonstrate that chiral symmetry and Lattice-QCD provide coherent constraints on the in-medium nuclear interaction, suggesting a fundamental origin of the saturation mechanism. [ABSTRACT FROM AUTHOR]

Quantum entanglement offers a unique perspective into the underlying structure of strongly-correlated systems such as atomic nuclei. In this paper, we use quantum information tools to analyze the structure of light and medium-mass berillyum, oxygen, neon and calcium isotopes within the nuclear shell model. We use different entanglement metrics, including single-orbital entanglement, mutual information, and von Neumann entropies for different equipartitions of the shell-model valence space and identify mode-entanglement patterns related to the energy, angular momentum and isospin of the nuclear single-particle orbitals. We observe that the single-orbital entanglement is directly related to the number of valence nucleons and the energy structure of the shell, while the mutual information highlights signatures of proton–proton and neutron–neutron pairing, as well as nuclear deformation. Proton and neutron orbitals are weakly entangled by all measures, and in fact have the lowest von Neumann entropies among all possible equipartitions of the valence space. In contrast, orbitals with opposite angular momentum projection have relatively large entropies, especially in spherical nuclei. This analysis provides a guide for designing more efficient quantum algorithms for the noisy intermediate-scale quantum era. [ABSTRACT FROM AUTHOR]

The neon isotopic chain displays a rich phenomenology, ranging from clustering in the ground-state of the self-conjugate doubly open-shell stable 20 Ne isotope to the physics of the island of inversion around the neutron-rich 30 Ne isotope. This second (i.e. Paper II) of the present series proposes an extensive ab initio study of neon isotopes based on two complementary many-body methods, i.e. the quasi-exact in-medium no-core shell model (IM-NCSM) and the projected generator coordinate method (PGCM) that is ideally suited to capturing strong static correlations associated with shape deformation and fluctuations. Calculations employ a state-of-the-art generation of chiral effective field theory Hamiltonians and evaluate the associated systematic uncertainties. In spite of missing so-called dynamical correlations, which can be added via the multi-reference perturbation theory proposed in the first paper (i.e. Paper I) of the present series [1], the PGCM is shown to be a suitable method to tackle the low-lying spectroscopy of complex nuclei. Still, describing the physics of the island of inversion constitutes a challenge that seems to require the inclusion of dynamical correlations. This is addressed in the third paper (i.e. Paper III) of the present series [2]. [ABSTRACT FROM AUTHOR]

Perturbative and non-perturbative expansion methods already constitute a tool of choice to perform ab initio calculations over a significant part of the nuclear chart. In this context, the categories of accessible nuclei directly reflect the class of unperturbed state employed in the formulation of the expansion. The present work generalizes to the nuclear many-body context the versatile method of Burton and Thom (J Chem Theory Comput 16(4):5586, 2020) by formulating a perturbative expansion on top of a multi-reference unperturbed state mixing deformed non-orthogonal Bogoliubov vacua, i.e. a state obtained from the projected generator coordinate method (PGCM). Particular attention is paid to the part of the mixing taking care of the symmetry restoration, showing that it can be exactly contracted throughout the expansion, thus reducing significantly the dimensionality of the linear problem to be solved to extract perturbative corrections. While the novel expansion method, coined as PGCM-PT, reduces to the PGCM at lowest order, it reduces to single-reference perturbation theories in appropriate limits. Based on a PGCM unperturbed state capturing (strong) static correlations in a versatile and efficient fashion, PGCM-PT is indistinctly applicable to doubly closed-shell, singly open-shell and doubly open-shell nuclei. The remaining (weak) dynamical correlations are brought consistently through perturbative corrections. This symmetry-conserving multi-reference perturbation theory is state-specific and applies to both ground and excited PGCM unperturbed states, thus correcting each state belonging to the low-lying spectrum of the system under study. The present paper is the first in a series of three and discusses the PGCM-PT formalism in detail. The second paper displays numerical zeroth-order results, i.e. the outcome of PGCM calculations. Second-order, i.e. PGCM-PT(2), calculations performed in both closed- and open-shell nuclei are the object of the third paper. [ABSTRACT FROM AUTHOR]

The goal of the present paper is twofold. First, a novel expansion many-body method applicable to superfluid open-shell nuclei, the so-called Bogoliubov in-medium similarity renormalization group (BIMSRG) theory, is formulated. This generalization of standard single-reference IMSRG theory for closed-shell systems parallels the recent extensions of coupled cluster, self-consistent Green's function or many-body perturbation theory. Within the realm of IMSRG theories, BIMSRG provides an interesting alternative to the already existing multi-reference IMSRG (MR-IMSRG) method applicable to open-shell nuclei. The algebraic equations for low-order approximations, i.e., BIMSRG(1) and BIMSRG(2), can be derived manually without much difficulty. However, such a methodology becomes already impractical and error prone for the derivation of the BIMSRG(3) equations, which are eventually needed to reach high accuracy. Based on a diagrammatic formulation of BIMSRG theory, the second objective of the present paper is thus to describe the third version (v3.0) of the ADG code that automatically (1) generates all valid BIMSRG(n) diagrams and (2) evaluates their algebraic expressions in a matter of seconds. This is achieved in such a way that equations can easily be retrieved for both the flow equation and the Magnus expansion formulations of BIMSRG. Expanding on this work, the first future objective is to numerically implement BIMSRG(2) (eventually BIMSRG(3)) equations and perform ab initio calculations of mid-mass open-shell nuclei. [ABSTRACT FROM AUTHOR]

In this paper we analyze the associated production of a vector meson with a (pseudo)scalar bound state or a dimuon system in ultraperipheral PbPb collisions through the double scattering mechanism for the energies of the Large Hadron Collider and Future Circular Collider. Our results complement previous studies for the double vector meson production. We present our predictions for the total cross sections and rapidity distributions considering the rapidity ranges covered by the ALICE and LHCb detectors, which indicate that a future experimental analysis of the ϕ + η c , ϕ + μ + μ - and J / Ψ + μ + μ - final states is feasible. [ABSTRACT FROM AUTHOR]

The damped oscillating structures were recently revealed in the proton “effective” form factor data. For the time being they can neither be confirmed nor disproved by investigations of the individual proton form factors data because the data have not yet achieved the required level of precision. On the other hand, conjectures that the oscillating structures are direct manifestations of the quark-gluon structure of the proton indicate that they should not be specific only to the proton and neutron. This opens a possibility to find these structures also in the data of other hadrons by the same procedure as for the proton. In this paper the oscillatory structures are investigated in the electromagnetic form factor data of the charged and neutral K-mesons. If the charged and neutral K-meson data are described by the three parametric formula by means of which the oscillating structures have been revealed for the proton (although with a large value of χ 2 / n d f ) then oscillating structures appear. On the other hand, if the physically well founded Unitary and Analytic model of the K-meson electromagnetic structure is used for the description of the charged K-meson data, no damped oscillating structures are visible. However, in the case of the neutral K-meson data one cannot make a definite conclusion, and more precise data are needed. These results indicate that also the damped oscillating structures obtained from the “effective” proton form factor data are likely an artefact of the three parametric formula, which cannot describe the data with sufficient precision. [ABSTRACT FROM AUTHOR]

High-energy γ rays are emitted either in the decay of nuclear discrete states (generally located in the proximity of the particle-emission threshold) or in the electromagnetic decay of collective states. The branching ratio is rather small, therefore in alternative/coincidence with high-energy γ rays one could have neutron or charged-particle emission. The precise measurement of these branching ratios allows a more comprehensive description of the nucleus and, in particular, the selection of the nuclear models which better describes the interplay between the different acting forces and couplings. In the case of the electromagnetic decay of collective states, the precise identification of the populated low-lying states allows the measurement of their wave-function and/or of their 'bulk' properties. This information provides, also in this case, a stringent test for the nuclear models. In both cases, to compensate these small branching ratio, a large number of detectors and an accurate selection of a small region of the phase space are needed. AGATA is considered to constitute an optimal array for this kind of measurements. In fact, AGATA, because of its high granularity and its excellent energy resolution, can detect the high-energy γ rays emitted in a specific decay path or associated to specific reaction channels, shapes, deformations. In the introduction, some details on the measurement of high-energy γ rays using HPGe detector are discussed. The sections of this paper focus on the measurements of high-energy γ rays to obtain the photon strength function, the nuclear level density and to identify extreme shapes in highly excited nuclei. [ABSTRACT FROM AUTHOR]

Samples made from natural bismuth were exposed in 60 MeV end-point bremsstrahlung beam. In this paper, a simple model for determination the share of two ways of 203Pb formation: by the decay of 203Bi, produced in 209Bi(γ,6n)203Bi reaction and by 209Bi(γ,p 5n)203Pb reaction is described. The method employs the ratio of 203Pb and 203Bi nuclei numbers and activities at the end of the exposure as the input value. This ratio was estimated from gamma spectra measured after irradiation of natural Bi sample. It was found that the rate of production of 203Pb by 209Bi(γ,p 5n)203Pb reaction is about 6% of the 203Bi production rate in the 209Bi(γ,6n)203Bi reaction. Obtained result is compared with TALYS based estimation. [ABSTRACT FROM AUTHOR]

The applicability of nuclear ab initio calculations has rapidly extended over the past decades. However, starting research projects is still challenging due to the required numerical expertise in the generation of underlying nuclear interaction matrix elements and many-body calculations. To ease the first issue, in this paper we introduce the numerical code NuHamil to generate the nucleon-nucleon (NN) and three-nucleon (3N) matrix elements expressed in a spherical harmonic-oscillator basis, inputs of many-body calculations. The ground-state energies for the selected doubly closed shell nuclei are calculated with the no-core shell-model (NCSM) and in-medium similarity renormalization group (IMSRG). The code is written in modern Fortran, and OpenMP+MPI hybrid parallelization is available for the 3N matrix-element calculations. [ABSTRACT FROM AUTHOR]

This paper presents research that focuses on nonflow contribution subtraction in heavy-ion collisions, using a multiphase transport model (AMPT). Specifically, the study aims to investigate the behavior of charged particle elliptic flow ( v 2 ) in d-Au collisions at a collision energy of s NN = 200 GeV and to determine the impact of nonflow sources, such as jet correlations and resonance decays, in small collision systems. To reduce nonflow effects, the per-trigger yield distribution in peripheral d-Au collisions or pp collisions with the same collision energy is subtracted. Our results show that the nonflow effects in central and mid-central collisions are not strongly dependent on subtracting the per-trigger yield distribution in peripheral d-Au collisions or pp collisions. Furthermore, the elliptic flow of charged particles, after removing nonflow effects through two subtracting methods from this work, exhibits consistency in various collision centrality classes. We also discuss comparisons with measurements from d-Au collisions at s NN = 200 GeV. Overall, this work provides valuable insights and serves as a reference for researchers studying nonflow contribution subtraction in experiments with small collision systems. [ABSTRACT FROM AUTHOR]

This article is a new edition of the review published six years ago by the same auhors [Eur. Phys. J. A 54, (2017) 218]. It includes additionally the most recent and significant results obtained in the field of heavy-ion fusion near and below the Coulomb barrier, which have been important for the advance of our knowledge. In particular, we present a selection of recent findings concerning the fusion dynamics of light systems, which is relevant for astrophysics, and moreover recent information obtained from measurements involving heavy-ion exotic beams. With respect to the previous paper, the description of relevant set-ups and methods is done in a dedicated Section. Recent advances obtained in the field of near and sub-barrier heavy-ion fusion reactions are reported. Early data on sub-barrier fusion taught us that cross sections strongly depend on the low-energy collective modes of the colliding nuclei, and on couplings to transfer channels. The coupled-channels model has been successful in the interpretation of the experiments, and fusion barrier distributions may yield the fingerprint of the relevant coupled channels. Far below the barrier, the slope of the excitation function keeps increasing in many cases and standard calculations over-predict the cross sections. This was named a hindrance phenomenon whose physical origin is a matter of debate. Recent theoretical developments suggest that hindrance may be a consequence of the Pauli exclusion principle. Hindrance has far-reaching consequences in astrophysics where the fusion of light systems determines stellar evolution during the carbon and oxygen burning stages. [ABSTRACT FROM AUTHOR]

This document is one of a series of white papers from the USQCD Collaboration. Here, we discuss opportunities for Lattice Quantum Chromodynamics (LQCD) in the research frontier in fundamental symmetries and signals for new physics. LQCD, in synergy with effective field theories and nuclear many-body studies, provides theoretical support to ongoing and planned experimental programs in searches for electric dipole moments of the nucleon, nuclei and atoms, decay of the proton, n- n ¯ oscillations, neutrinoless double- β decay of a nucleus, conversion of muon to electron, precision measurements of weak decays of the nucleon and of nuclei, precision isotope-shift spectroscopy, as well as direct dark matter detection experiments using nuclear targets. This white paper details the objectives of the LQCD program in the area of Fundamental Symmetries within the USQCD Collaboration, identifies priorities that can be addressed within the next five years, and elaborates on the areas that will likely demand a high degree of innovation in both numerical and analytical frontiers of the LQCD research. [ABSTRACT FROM AUTHOR]

Prompt emission calculations for the photon induced fission of 238U and 232Th in the GDR energy region were performed by using (a) a systematic of input parameters for the most probable fragmentation approach (obtained on the basis of only spontaneous and neutron induced fission of actinides) and (b) photo-fission cross section ratios (expressing the fission probabilities at incident energies where multiple fission chances are involved) provided by nuclear reaction calculations performed with the EMPIRE code. The prompt neutron emission results describe well the experimental data recently measured at the laser Compton-scattering γ-ray source of the NewSUBARU facility, validating the use of this input parameter systematic for photon induced fission, too. The modelings and procedures described in this paper can constitute an useful tool for the prediction of prompt neutron emission data in photon induced reactions without any experimental information. [ABSTRACT FROM AUTHOR]

A recent study found a new, purely empirical correlation between two-neutron separation energies and neutron capture cross sections in keV neutron energy regimes. In shape/phase transition regimes, such as that near A= 150, S 2 n values show an anomaly—a flattening of the normal near linear decrease with neutron number. This paper addresses two questions: (1) Using this new correlation, is this anomaly in S 2 n values sizeable enough to produce an observable effect in capture cross sections? and (2) Can the correlation be used to quantitatively reproduce the cross sections in the transition region? It is found that the answer to both questions is in the affirmative. Possible relations to the r-process are briefly discussed. [ABSTRACT FROM AUTHOR]

The paper is the third of a series dedicated to the ab initio description of monopole giant resonances in mid-mass closed- and open-shell nuclei via the so-called projected generator coordinate method. The present focus is on the computation of the moments m k of the monopole strength distribution, which are used to quantify its centroid energy and dispersion. First, the capacity to compute low-order moments via two different methods is developed and benchmarked for the m 1 moment. Second, the impact of the angular momentum projection on the centroid energy and dispersion of the monopole strength is analysed before comparing the results to those obtained from consistent quasi-particle random phase approximation calculations. Next, the so-called energy weighted sum rule (EWSR) is investigated. First, the appropriate ESWR in the center-of-mass frame is derived analytically. Second, the intrinsic EWSR is tested in order to quantify the (unwanted) local-gauge symmetry breaking of the presently employed chiral effective field theory (χ EFT) interactions. Finally, the infinite nuclear matter incompressibility associated with the employed χ EFT interactions is extracted by extrapolating the finite-nucleus incompressibility computed from the monopole centroid energy. [ABSTRACT FROM AUTHOR]

Retraction Note: Direct measurements of the 12C + 12C reactions cross-sections towards astrophysical energies After publication, we discovered a mistake in the script used to calculate beam energy losses from tabulated stopping powers. We deeply regret any inconvenience that this retraction may cause, and we apologize to the scientific community and to the readers of EPJA for any harm that may have been caused by the publication of this paper. [Extracted from the article]

Initially, yields (or abundances) and branching ratios of β-delayed neutrons (βdn) from fission products (Pn-values) have had their main importance in nuclear reactor control. At that time, the six-group mathematical approximation of the time-dependence of βdn-data in terms of the so-called "Keepin groups" was generally accepted. Later, with the development of high-resolution neutron spectroscopy, βdn data have provided important information on nuclear-structure properties at intermediate excitation energy in nuclei far from stability, as well as in nuclear astrophysics. In this paper, I will present some examples of the βdn-studies performed by the Kernchemie Mainz group during the past three decades. This work has been recognized as an example of "broad scientific diversity" which has led to my nomination for the 2014 Hans A. Bethe prize. [ABSTRACT FROM AUTHOR]

Presently, γ -ray tracking in germanium segmented detectors is realised by applying two advanced, complex algorithms. While they have already triggered an intensive R &D, they are still subject to further improvements. Running the common code for these core algorithms in both the online/real-time and offline data pipelines posed significant challenges. These were addressed in current production software, but also require continued attention in view of significant on-going paradigm shifts in both hardware and software technology. This review paper gives an overview of the various software components produced so far by the AGATA collaboration. It provides hints of what is foreseen for the next phases of the project up to its full configuration namely with 180 capsules in the array. [ABSTRACT FROM AUTHOR]

AGATA is a modern γ -ray spectrometer for in-beam nuclear structure studies, based on γ -ray tracking. Since more than a decade, it has been operated performing experimental physics campaigns in different international laboratories (LNL, GSI, GANIL). This paper reviews the obtained results concerning the performances of γ -ray tracking in AGATA and associated algorithms. We discuss γ -ray tracking and algorithms developed for AGATA. Then, we present performance results in terms of efficiency and peak-to-total for AGATA. The importance of the high effective angular resolution of γ -ray tracking arrays is emphasised, e.g. with respect to Doppler correction. Finally, we briefly touch upon the subject of γ -ray imaging and its connection to γ -ray tracking. [ABSTRACT FROM AUTHOR]

In this paper, we present comprehensive results on intermittency using the Scaled Factorial Moment (SFM) technique in Au + Au collisions in the FAIR energy range of 2–12A GeV in pseudorapidity χ (η) , azimuthal χ (ϕ ), and pseudorapidity-azimuthal χ (η - ϕ ) spaces. The simulations are performed with a hybrid version of the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) event generator. Three alternative equations of state (EoS) are employed to investigate the intermittency within the hydrodynamic scenario, namely pure Hadron Gas (HG), Chiral + HG, and Bag Model EoS. In both one and two-dimensional spaces and at all beam energies, a weak intermittent type of emission has been seen for Chiral+HG EoS. In contrast, a strong intermittent kind of emission is observed for Bag Model EoS. The incident beam energy dependency of intermittency has also been investigated. The strength of the intermittency is seen to diminish with increasing beam energy. [ABSTRACT FROM AUTHOR]

Heavy ion storage rings are powerful tools to store and observe key nuclear properties of rare radioactive isotopes. Recent developments in ring physics and enhanced beam intensities have now opened up the possibility to carry out low-energy investigations of nuclear reactions at rings. Pure, intense, exotic beams of isotopes that are otherwise challenging to access can be impinged on pure, ultra-thin targets, allowing the study of long-standing nuclear astrophysical puzzles in a variety of stellar sites that have so far resisted traditional approaches. In this review paper, we will describe pioneering studies with decelerated beams at the ESR storage ring at GSI (Germany), as well as future exciting prospects at the ESR and CRYRING at GSI/FAIR. [ABSTRACT FROM AUTHOR]

The energy density functional (EDF) method is currently the only microscopic theoretical approach able to tackle the entire nuclear chart. Nevertheless, it suffers from limitations resulting from its empirical character and deteriorating its reliability. This paper is part of a larger program that aims at formulating the EDF approach as an effective field theory (EFT) in order to overcome these limitations. A relevant framework to achieve this is the path-integral formulation of quantum field theory. The latter indeed provides a wide variety of treatments of the many-body problem well suited to deal with non-perturbative interactions and to exploit a Lagrangian resulting from an EFT as a starting point. While developing the formalism in a general setting, we present below a comparative study of such techniques applied to a toy model, i.e. the (0 + 0)-D O(N)-symmetric φ 4 -theory. More specifically, our focus will be on the following diagrammatic techniques: loop expansion, optimized perturbation theory and self-consistent perturbation theory. With these methods, we notably address the spontaneous breakdown of the O(N) symmetry with care especially since spontaneous symmetry breakings play a paramount role in current implementations of the EDF approach. [ABSTRACT FROM AUTHOR]

In this paper, the usual momentum- and coordinate-space distance criteria for creating nuclear clusters in transport simulations are readdressed by using a dynamical, covariant description in an off-shell Boltzmann-Uehling-Uhlenbeck transport approach. The free parameter of this clustering scheme is the cluster formation time, which is fitted through the FOPI data of low energy charged cluster multiplicities in Au+Au collisions at 150 A MeV, and 400 A MeV incident energies. The coalescence model is used to estimate the yields of the 3 H Λ , 5 H Λ Λ , 6 He Λ Λ single and double strange hypernuclei in central Au+Au collisions between 2, and 20 A GeV incident energies, giving comparable results to estimations from other methods. [ABSTRACT FROM AUTHOR]

Nucleon form factors play an especially important role in studying the dynamics of nucleons and explicit structure of the wave functions at arbitrary nucleon velocity. The purpose of the paper is to explain theoretically all four nucleon form factors measured experimentally in the cross section measurements (by the Rosenbluth method), yielding almost equal normalized form factors G E p , G M p , G M n ), as well as in the polarization transfer experiments, where a strongly decreasing proton electric form factor has been discovered. It is shown, using relativistic hyperspherical formalism, that the nucleon wave functions in the lowest (hypercentral) approximation provide almost equal normalized form factors as seen in the Rosenbluth cross sections, but in the higher components they contain a large admixture of the quark orbital momenta, which strongly decreases G E p and this effect is possibly detected in the polarization transfer method (not seen in the classical cross section experiments). Moreover, the same admixture of the higher components explains the small positive form factor G E n , which is zero in the hypercentral approximation. The resulting form factors, G M p (Q) , G E p (Q) , G M n (Q) are calculated up to Q 2 ≈ 10 GeV 2 , using the the Lorentz contracted nucleon wave functions and shown to be in reasonable agreement with experimental data. [ABSTRACT FROM AUTHOR]

The Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, provides unique possibilities for a new generation of hadron-, nuclear- and atomic physics experiments. The future antiProton ANnihilations at DArmstadt (PANDA or P ¯ ANDA) experiment at FAIR will offer a broad physics programme, covering different aspects of the strong interaction. Understanding the latter in the non-perturbative regime remains one of the greatest challenges in contemporary physics. The antiproton–nucleon interaction studied with PANDA provides crucial tests in this area. Furthermore, the high-intensity, low-energy domain of PANDA allows for searches for physics beyond the Standard Model, e.g. through high precision symmetry tests. This paper takes into account a staged approach for the detector setup and for the delivered luminosity from the accelerator. The available detector setup at the time of the delivery of the first antiproton beams in the HESR storage ring is referred to as the Phase One setup. The physics programme that is achievable during Phase One is outlined in this paper. [ABSTRACT FROM AUTHOR]

In this paper we analyze the associated ϕ and J / Ψ photoproduction in ultraperipheral PbPb collisions through the double scattering mechanism for the energies of the Large Hadron Collider (LHC) and Future Circular Collider (FCC). Our results complement a previous analysis for the ρ ρ , J / Ψ J / Ψ and ρ J / Ψ production. We present our predictions for the total cross sections and rapidity distributions considering the rapidity ranges covered by the ALICE and LHCb detectors, which indicate that a future experimental analysis of ϕ J / Ψ final state is feasible. These results point out that the study of the double vector meson photoproduction in heavy ion collisions can be useful to constrain the double scattering mechanism and improve our understanding of the QCD dynamics at high energies. [ABSTRACT FROM AUTHOR]