bluuebunny/crossref_metadata_2025_split huggingface dataset:
The quantification of pairing interaction in a two-neutron transfer through the intermediary continuum
Authors: Singh G. , Fortunato L. , Vitturi A. 
Published: September 2023

Abstract
An unbound intermediate system (A+1) with the presence of a resonance, can aid in the pairing enhancement in a two-neutron transfer reaction from a bound system A to another bound system (A+2). This enhancement is a consequence of the constructive interference via the several reaction channels available in the (A+1) system. We test this feature through our study in 6He, modeled as two neutrons in the orbitals of an intermediate 5He nucleus. Weighing up the natural case of an unbound 5He with a hypothetically bound 5He, we find that the inclusion of a properly modeled continuum favours the pairing correlations leading to enhanced two-neutron transfer cross-sections.
Deblurring decay-energy distribution from an invariant-mass measurement
Authors: Nzabahimana Pierre , Redpath Thomas , Baumann Thomas , Danielewicz Pawel , Giuliani Pablo , Guèye Paul 
Published: September 2023

Abstract
Measured decay-energy spectra from invariant mass spectroscopy can give insights into the shell structure of particle-unbound systems. However, it is challenging to extract the underlying physics from a measured spectrum due to detector resolution and acceptance effects. In this work, we introduce a deblurring method used to restore the decay energy spectrum measured for the three-body decay of 26O. The method utilizes the Richardson-Lucy algorithm, which has proven to be successful in optics, and does not require any prior knowledge about the resonance states in the observed spectrum. It also circumvents the singularity issue by iteratively adjusting a positive definite distribution. The only inputs are the observed energy spectrum and the detector’s response matrix also referred to as the Transfer Matrix (TM). We test the method’s performance on a simulated spectrum using the MoNA-LISA-Sweeper setup and the associated TM. Finally, the approach is applied to the decay energy spectrum of the 26O system measured in an experiment conducted at the National Superconducting Cyclotron Laboratory (NSCL) by the Modular Neutron Array (MoNA) Collaboration. The deblurring approach suggests three peaks in the decay energy spectrum of 26O at 0.15, 1.5 MeV, and a broad peak between 4 and 6 MeV.
The model for describing the width of double-gamma decay of the quadrupole state of spherical nuclei
Authors: Severyukhin A. P. , Arsenyev N. N. 
Published: September 2023

Abstract
We study the competitive γγ-decay of the

2
1
+

state of an even-even spherical nucleus. An influence of the phonon-phonon coupling on the double γ-decay width is analysed within the microscopic model based on the Skyrme energy density functional. It is shown that the γγ-decay width is sensitive to the interaction of the one- and two-phonon configurations of the giant dipole resonance.
Production of nuclei and hypernuclei in relativistic ion reactions
Authors: Botvina A S , Bleicher M , Buyukcizmeci N 
Published: September 2023

Abstract
We study the production of small nuclei, nuclei of intermediate mass, and hypernuclei in relativistic nuclear reactions by using dynamical and statistical models. We propose a novel mechanism responsible for the formation of complex nuclei from nucleons and hyperons produced in collisions: In this reaction the excited clusters consisting of baryons can stochastically be formed at a low sub-nuclear density after the dynamical expansion of the nuclear matter. One can describe the nucleation process within such clusters with the statistical models. We suggest the hybrid approach allowing for the consistent description of the experimental data measured in central collisions, which was not possible with other theoretical methods. The important consequence of this novel mechanism is the correlations of the produced nuclear species. The energy limits for describing the fragmentation and nucleation processes in excited finite nuclear systems with statistical models are also obtained.
Isoscalar giant monopole resonance in 40,48Ca
Authors: Arsenyev N. N. , Severyukhin A. P. 
Published: September 2023

Abstract
Starting from the Skyrme energy-density functional, the microscopic model is developed for the monopole excitations. We take into account the coupling between one-, two-, and three-phonon terms in the wave functions of excited 0+ states. As an example, the properties of the isoscalar giant monopole resonance (ISGMR) for the doubly magic nuclei 40,48Ca are discussed. The inclusion of complex configurations leads to a fragmentation of the ISGMR strength to lower energy 0+ states and also higher energy tail.
Towards microscopic optical potentials in deformed nuclei
Authors: Idini A , Rotureau J , Boström J , Ljungberg J , Carlsson B G 
Published: September 2023

Abstract
A microscopic and consistent description of both nuclear structure and reactions is instrumental to extend the predictivity of models calculating scattering observables. In particular, this is crucial in the case of exotic nuclei not yet discovered.
In this manuscript, we will present the plan of the Lund effort for a symmetry breaking description of bound and scattering observables using a generator coordinate method model based on an effective Hamiltonian constrained with a (Skyrme) functional. Following this, we will illustrate the steps to construct an optical potential for deformed nuclei from microscopic wavefunctions obtained with projected generator coordinate method from Hartree-Fock-Bogoliubov basis.
Fusion barrier distribution from measurement of quasielastic scattering at θ
c.m. = 180°
Authors: Biswas Rohan , Nath S , Gehlot J , Gonika  , Kumar Chandra , Parihari A , Madhavan N , Vinayak A , Mahato Amritraj , Noor Shoaib , Sherpa Phurba 
Published: September 2023

Abstract
Distribution of fusion barriers reveals the effect of structure of the collision partners on the dynamics of fusion between two heavy ions. Experimental barrier distribution can be extracted from precisely measured fusion excitation function. Quasielastic excitation function is related to fusion excitation function by conservation of incident flux. Hence, barrier distribution can also be extracted from quasielastic excitation function, which is usually measured at large angles, by detecting the back-scattered projectile-like ions. However, the reflectance coefficient is exactly complementary to the transmittance coefficient at θ
c.m. = 180°, which corresponds to orbital angular momentum, ℓ = 0. We report here extraction of fusion barrier distribution for 16O+142 Ce from measurement of quasielastic scattering at θ
c.m. = 180°, by detecting the target-like ions in the forward angles using a recoil mass spectrometer. Quasielastic excitation functions were also measured by detecting the projectile-like ions at two large angles. Barrier distributions extracted from both fusion and quasielastic measurements were found to be nearly identical. This work, thus, provided the first experimental verification of validity of the scaling property and the iso-centrifugal approximation in extracting barrier distribution from quasielastic excitation functions measured at large angles.
Two proton emission and other exotic decays in the 48Ni region with ACTAR TPC
Authors: Ortega Moral A. ,   E791 Experiment Collaboration
Published: September 2023

Abstract
Since the first indirect measurements of the two proton radioactivity in 2002 [1], some theoretical descriptions have been able to reproduce experimental results until the 2-proton radioactivity was established for 67Kr at RIKEN [2], with a lifetime about 20 times lower than expected. New theory inputs have recently been developed [3][4], predicting angular distributions of the emitted protons for some of the two proton emitters, that need to be confirmed experimentally. An experiment at GANIL/LISE3 facility was performed in May 2021 aiming to produce one of the 2 proton emitters (48Ni) and measure the angular distribution of the emitted protons. We used the ACTAR TPC detector to implant the ions and perform the tracking of their proton decays. In addition, other exotic nuclei in the 48Ni region were produced. For several of them we have found a first evidence of exotic decays such as β delayed 3- and 2-proton emission or low energy proton branches for β delayed single proton emission. The analysis of this decays will provide helpful experimental information about the structure and the partial decay schemes of these unstable nuclei.
Precise mass measurement of the 32S member of the (A=32, T=2) quintet of analogue states
Authors: Blank B , Thomas J.-C , Gerbaux M , Ascher P , Atanasov D , Cresto F , Délignac Q , de Roubin A , Flayol M , Gendre Q , Giovinazzo J , Grévy S , Husson A , Jurado B , Kurtukian Nieto T , Marini P , Mathieu L , Michaud J , Ortega Moral A , Sguazzin M , Swartz J A , Versteegen M 
Published: September 2023

Abstract
This contribution presents a precise measurement of the excitation energy of the lowest (0+, T=2) state in 32S. Combined with the mass excesses of the 32S ground state and of the four other members of the (A=32,T=2) quintet of analogue states, it allows to test the validity of the Isobaric Multiplet Mass Equation to the third order in Tz, which renders it highly sensitive to the mechanisms inducing isospin mixing in the involved sd-shell nuclei. The (0+, T=2) isobaric analogue state in 32S was resonantly populated in the 31P(p, γ) reaction at ~3.3 MeV incident energy. The measurement procedure, involving high-purity germanium detectors, is described and the preliminary result obtained with a digital data acquisition system is presented.
Shell effects in fission and quasi-fission reactions
Authors: Simenel C. , Godbey K. , Lee H. , McGlynn P. , Umar A.S. 
Published: September 2023

Abstract
Quantum shell effects are responsible for asymmetric fission. They are also expected to affect the formation of fission fragments in quasi-fission reactions occurring in heavy-ion collisions. Systematic time-dependent Hartree-Fock simulations of 40–56Ca+176Yb collisions show that quasi-fission fragment properties share strong similarities with fragments formed in fission of the compound nuclei. This is an indication that similar shell effects are responsible for the final asymmtery in both mechanisms.
Investigating the pygmy dipole resonance in 96Mo using the (p,d) reaction
Authors: Khumalo T C , Pellegri L , Wiedeking M , Cappuzzello F , Cavallaro M , Carbone D , Spatafora A , Adsley P , Agodi C , Brischetto G , Calabrese S , Ciraldo I , Isaak J , Jivan H , Jongile S , La Fauci L , Lanza E G , Malatji K L , Netshiya A A , Neveling R , Sgouros O , Sideras-Haddad E , Soukeras V , Torresi D 
Published: September 2023

Abstract
The pygmy dipole resonance (PDR) thus far has been described microscopically as a cluster of 1− states around the neutron separation energy (S
n
). This study is an attempt to probe the nature of the PDR, specifically the single-particle or collective character of these states. One-step transfer reactions represents a good probe for this study due to their selectivity in exciting single-particle states. The 97Mo(p,d) 96Mo and 95Mo(d,p)96Mo reactions, were used to populate the nucleus of interest. The experiment was conducted at the INFN-LNS facility in Catania, Italy. The ejectiles were momentum-analysed by the MAGNEX spectrometer and detected by its focal-plane detector. In this paper, preliminary results for the 97Mo(p, d) 96Mo reaction will be presented.
β-decay studies in the 220 <A< 230 Po-Fr region
Authors: Polettini M , Benzoni G , Pellumaj J , Valiente-Dobón J J , Zhang G , Mengoni D , Perez Vidal R M , Huang Z. , Bracco A ,   HISPEC-DESPEC collaboration for S460 experiment
Published: September 2023

Abstract
The experimental study presented in this work aims at providing new inputs to the knowledge of β decay in the 220<A<230 n-rich region.
A systematic description of β decay in this region would be useful to probe the predictions of global nuclear models in exotic nuclei beyond N= 126, as an input to models describing r-process nucleosynthesis. The region mentioned is also one of the regions in the nuclear chart where the strongest octupole deformations are supposed to be found, and were measured experimentally in recent years in few selected cases.
This work focuses on preliminary results on an experiment performed by the HISPEC-DESPEC collaboration as a part of the FAIR-0 campaing in April 2021. β-decay half lives and γ-ray spectra studies are presented.
Evolution of fragment production at the onset of Multifragmentation
Authors: Geraci E , Cardella G , Colonna M , De Filippo E , Gnoffo B , Maiolino C , Martorana NS , Pagano A , Pagano EV , Pirrone S , Politi G , Russotto P , Rizzo F , Trifiró A , Trimarchi M , Barlini S , Bougault R , Casini G , D’Agostino M , Gramegna F , Le Neindre N , Piantelli S 
Published: September 2023

Abstract
The onset of Multifragmentation phenomenon is investigated at low excitation energies. A detailed study on the origin of Intermediate Mass Fragment (IMF, Z>=3) produced in central collisions in the 58Ni+40Ca reaction at 25 AMeV is presented. The experimental campaign was performed with CHIMERA multi-detector at INFN Laboratori Nazionali del Sud in Catania (Italy). The multiple identification techniques of the 4p apparatus, together with low detection thresholds, enable the performance of a careful selection of Fusion-evaporation residues, Multifragmentation sources and their decay products. Comparisons with dynamical approach based on Boltzmann-Langevin-One-Body (BLOB) model predictions coupled with sequential emission code, were used as useful tools to depict and understand the characteristics of fragments emitted from an equilibrated compound nucleus or formed simultaneously in the multifragmenting source. A comparison with the preliminary results obtained for fragment production in central collisions of the same system, 58Ni+40Ca, at higher incident energies Ebeam=35AMeV, allows to study and characterize the evolution of multifragmentation phenomenon at the lower end of Fermi energies.
The 46Ar(3He, d)47K direct reaction as a probe of the 46Ar proton wavefunction
Authors: Brugnara D , Gottardo A , Assié M , Mengoni D , Lemasson A , Clement E , Flavigny F , Ramos D , Galtarossa F , Matta A , Girard-Alcindor V , Babo M , Bazzacco D , Beaumel D , Blumenfeld Y , Bottoni S , Datta U , de Angelis G , de France G , Dudouet J , Duenas J , Goasduff A , Gregor E T , Hammache F , Illana A , Lalanne L , Leblond S , Lombardo I , Marchini N , Million B , Recchia F , Rezynkina K , Rocchini M , Rojo J S , Siciliano M , Valiente-Dobón J J , Zanon I , Zielinska M 
Published: September 2023

Abstract
The discrepancy between shell-model calculations and intermediate-energy Coulomb excitation measurements in 46Ar still stands as an unsolved puzzle in understanding the N = 28 shell evolution. This phenomenon has significant relevance considering the remarkable achievements of the shell model and the SDPF-U interaction in the region which is able to predict the fading of the N = 28 shell gap in neutron-rich 44S. Recent measurements narrowed down this discrepancy to an overestimation of the proton amplitude to the quadrupole transition matrix element. The current work aims to propose a different perspective on the puzzle, by studying a direct proton-transfer reaction on 46Ar as a means to directly probe the proton wavefunction of the ground state this isotope. By measuring the amount of l = 0 transfer to the ground state (1/2+) of 47K with respect to the l = 2 to the first excited state (3/2+), we aim to gain insight into the ground state proton wavefunction of 46Ar. We will present a brief description of the experiment performed at the SPIRAL1 facility in GANIL (France). The experimental apparatus allowed a full reconstruction of the two-body reaction thanks to the combination of AGATA, VAMOS, MUGAST, CATS2, and HECTOR.
Differential Cross Section for Proton Induced Deuteron Breakup at 108 MeV
Authors: Łobejko A. , Kalantar–Nayestanaki N. , Kistryn S. , Kłos B. , Kozela A. , Kulessa P. , Parol W. , Skwira-Chalot I. , Stephan E. , Szadziński A. , Wilczek A. , Włoch B. , Zejma J. 
Published: September 2023

Abstract
The differential cross sections for the proton-deuteron breakup reaction have been measured for more than 200 angular configurations of outgoing protons in the range of polar angles from 13 to 27 degrees with a proton beam at 108 MeV. The paper presents the experimental results of the selected configurations, which are compared to state-of-the-art theoretical calculations. In some regions of the phase space, a strong influence of the Coulomb interaction is observed.
Proton halo effects in the 8B+64Zn collision around the Coulomb barrier
Authors: Di Pietro A , Spartá R , Figuera P , Tengblad O , Moro A , Lei J , Fernandez Garcia JP , Acosta L , Jonson B , Borge MJ , Cederkäll J , Davinson T , Ovejas JD , Fraile L , Galaviz D , Halkjaer Jensen J , La Cognata M , Martel I , Perea A , Sanchez Benitez A , Soić N , Vignales S 
Published: September 2023

Abstract
The 8B+64Zn reaction at 38.5 MeV has been studied at HIE-ISOLDE CERN to investigate proton halo effect on the reaction dynamics. For the first time it was used the only existing post-accelerated 8B beam. The measured elastic scattering angular distribution showed a small suppression of the Coulomb-nuclear interference peak, opposite to what observed for the one-neutron halo nucleus 11Be on the same target where a large suppression was observed instead. Inclusive angular and energy distributions of breakup fragments were also measured showing that, both, elastic and non-elastic breakup contribute. The presence of the additional Coulomb interactions halo-core and halo-target in 8B makes the reaction dynamics in this proton-halo nucleus different than the neutron-halo case.
Spectroscopic factors with generator coordinate method and application to 25Mg states
Authors: Boström J , Rotureau J , Ljungberg J , Carlsson B G , Idini A 
Published: September 2023

Abstract
Nuclei can be studied through the analysis of their shell structure, that provides important information on the wavefunctions useful for interpreting many phenomena, from excitations to transfer reactions. Spectroscopic factors provide the degree of single particle behaviour of a nuclear state and are used to represent the shell structure of a nucleus.
In this manuscript, we expand our recently developed model, which uses the generator coordinate method with an effective Hamiltonian, to calculate spectroscopic factors of states of odd deformed nuclei. Here we provide the results for 25Mg.
New results on the decay spectroscopy of 254No with GABRIELA@SHELS
Authors: Forge M. , Dorvaux O. , Lopez-Martens A. , Kessaci K. , Gall B.J.P. , Hauschild K. , Asfari Z. , Chakma R. , Yeremin A.V. , Chelnokov M.L. , Chepigin V.I. , Isaev A.V. , Izosimov I.N. , Katrasev D. , Kuznetsova A.A. , Malyshev O.N. , Mukhin R. , Popeko A.G. , Popov Yu.A. , Svirikhin A.I. , Sokol E.A. , Tezekbayeva M.S. , Piot J. 
Published: September 2023

Abstract
The structure of the

102

254

No

152

nucleus has been studied for more than 20 years: the last publications on its decay spectroscopy are from LBNL [1], GSI [2], JYFL [3] and ANL [4]. Four decay schemes featuring two isomers have been published and are interpreted differently in terms of excitation energy and decay scheme of the 2
nd
isomer and configuration assignments of both K-isomers. These discrepancies have triggered new experiments including this one, performed with the GABRIELA [5, 6] array, at the focal plane of the SHELS [7] separator at the FLNR, Dubna. The first part of this proceeding will present the experimental setup and the analysis techniques used to reveal the electromagnetic decay of the known isomers in 254No. The second part will focus on the new results obtained with more than 1 million 254No nuclei implanted in the focal plane detector. In particular, the internal conversion electron spectrum observed in the decay of the 8− K-isomer has revealed the presence of a strong transition, most likely E0, suggesting low-lying shape coexistence in this nucleus as predicted in [8, 9]. The γ-ray spectrum obtained from the decay of the short-lived 170 μs isomer has revealed new γ-ray lines putting in doubt the previous interpretations about this isomer decay.
Pygmy Dipole Response in Samarium isotopes
Authors: Jivan H , Pellegri L , Adsley P. , Bahini A. , Brummer J.W. , Donaldson L.M. , Färber M. , Görgen A. , Jones P. , Jongile S. , Khumalo T. , Li K.C.W. , Marin-Lambarri D.J. , Lanza E.G. , Negret A. , von Neumann-Cosel P. , Neveling R , Olacel A. , Papka P. , Pesudo V , Savran D. , Sideras-Haddad E. , Siem S. , Smit F.D. , Steyn G.F. , Usman I. , Van Zyl J.J , Wiedeking M. , Weinert M. 
Published: September 2023

Abstract
The influence of nuclear shape deformation on the Pygmy Dipole Response (PDR) was investigated using (α,α′γ) scattering on 144Sm and 154Sm. Experiments were conducted at iThemba LABS, coupling for the first time the K600 magnetic spectrometer with the BaGeL (Ball of Germanium and LaBr detectors) array. Preliminary results showcasing the efficacy of the facility and set-up for performing these 0° scattering experiments to investigate the PDR region are presented.
Exploring shape coexistence in A < 190 nuclei through EM transition rate measurements
Authors: Chamoli S.K. , Bhushan Ravi , Pandey Anand 
Published: September 2023

Abstract
The nuclei having mass A ~ 190 exhibit some interesting structural phenomenon like shape coexistence and shape transition. The present work reports on some of the experimental evidence of shape coexistence in this mass region for some of the nuclei. To establish experimentally the shape of a nucleus and hence the presence of shape coexistence demands use of experimental tools such as coulomb excitation or lifetime measurements. Various possible measurable quantities and associated phenomena are discussed, together with details on experiments performed. Experiments performed to populate different isotopes in Tl, Pt and Hg nuclei. Several theoretical and experimental calculations suggest the presence of shape coexistence in different isotopes of Tl, Pt and Hg nuclei.