Within the transport model evaluation project (TMEP collaboration) of simulations for heavy-ion collisions, the mean-field dynamics of local density fluctuations is examined in several transport models widely employed to describe nuclear reactions.
The results of transport codes belonging to two families (BUU-like and QMD-like) are compared among each other and to exact calculations. For...
The antisymmetrized molecular dynamics (AMD)[1] is one of the most successful transport models, applied in intermediate heavy ion collisions. AMD usus a frozen (crystal) concept for the initial nuclei and the Fermi motion is taken into account as an average Fermi energy, T0 ~ 9 MeV/nucleon, in the energy calculation. This brings the stability of the initial nuclei in the time evolution, but...
Abstract: In this study, we analyze the experimental data from heavy-ion collision (HIC) using 40Ca and 48Ca beams at 140 MeV/u impinging on 58Ni and 64Ni targets. The experimental set up includes a charged particle array HiRA10 and the neutron wall array, LANA. From the charged particles, we construct coalescence invariant ratios of pseudo-neutrons and protons as a function of transverse...
The complete microscopic description of the fission process is still a challenge for nuclear theory. Density functional theory (DFT) and Time-Dependent DFT are tools of choice to describe fission. However, it can be difficult to extract information about the fragments that are needed for comparison with experience or as input for the r-process model.
In this presentation, I will discuss...
J. Benlliure 1 , J. Díaz 1 , H. Alvarez-Pol 1 , T. Aumann 2 , C.A. Bertulani 3 , B. Blank 4 , E. Casarejos 1 , D. Cortina 1 , D. Dragosavac 1 , V. Fohr 5 , A. Gargano 6 , M. Gascón 1 , W. Gawlikowicz 7 , A. Heinz 5 , K. Helariutta 8 , A. Kelic 5 , F. Montes 5 , L. Pienkowski 7 , J.L. Rodríguez-Sánchez 1 , K.-H. Schmidt 5 , M. Staniou 5 , K. Subotic 9 , K. Summerer 5 , J. Taieb 10 , A....
Density determinations for neck fragmentation (ternary reactions) has been shown [1] for the reaction 124Sn + 64Ni at 35 AMeV, as investigated by using the CHIMERA multi-detector [2]. The analysis is now applied to the system 112Sn + 58Ni and the reactions induced by 124Xe on 64Zn and 64Ni targets at the same incident energy. In these last cases the two systems differ only for the target...
The nuclear caloric curve is an emergent property of the nuclear equation of state. Some models predict the caloric curve depends on the neutron excess, but the magnitude and even sign of this dependence varies between models. We aim to characterize the asymmetry dependence of the nuclear caloric curve experimentally. Since the caloric curve emerges from the microscopic interaction, knowledge...
B. Borderie et al. - INDRA Collaboration
By using freeze-out properties of multifragmenting hot nuclei produced in quasi-fusion central 129 Xe+ nat Sn collisions at different bombarding energies (32, 39, 45 and 50 AMeV) which were estimated by means of a simulation based on experimental data collected by the 4π INDRA multidetector, heat capacity in the thermal excitation energy range 4 -...
In the transition from nuclear matter to finite nuclei, complex finite-size effects which characterise open systems arise, in relation with either the nuclear surface or the bulk. In addition, the non-equilibrium character of the process, typical of violent heavy-ion collisions (from Fermi energy to the intermediate-energy domain) adds up as well. The resulting dynamics is the combination of...
Depending on the energy regime, the dynamics of heavy-ion collisions reveals a variety of different mechanisms which are attributed to the combination of collective and dissipative effects.
Whereas at low and high energies only one of the two contributions tends to prevail, the description of Fermi-to-intermediate energy regimes imposes to address the interplay between collective and chaotic...
Isospin transport ratio is a powerful method to estimate the neutron-proton (n-p) equilibration in heavy-ion collisions, and extensively used to obtain information on the asy-stiffness of the nuclear Equation of State. In fact such a ratio is expected to bypass any perturbations introducing a linear
transformation of the chosen observable. In particular, it is supposed to overcome...
B. Gnoffo1,2, S. Pirrone2, G. Politi1,2, L. Acosta2,3, G. Cardella2, E. De Filippo2, E. Geraci1,2, L. Lo Monaco1, C. Maiolino4, N.S. Martorana1,4, A. Pagano2, E.V. Pagano4, M. Papa2, F. Risitano2,5, F. Rizzo1,4, P. Russotto4 and M. Trimarchi2,5
1) Dipartimento di Fisica e Astronomia E. Majorana, Università di Catania, Italy
2) INFN-Sezione di Catania, Italy
3) Instituto de Fisica,...
We investigated the possibility to probe the symmetry energy term of the nuclear equation of state with isoscaling observables from 40,48 Ca+ 40,48 Ca reactions at 35 AMeV . Data were obtained using the unique coupling of the VAMOS high acceptance spectrometer and the 4π INDRA detector. This required a precise study of the trajectory reconstruction in the spectrometer focal plane along with...
J. Quicray
On behalf of the INDRA and FAZIA collaborations
Normandie Univ, ENSICAEN, UNICAEN, CNRS/IN2P3, LPC Caen, 14000 Caen, France
The study of fragmentation reactions produced in heavy-ion collisions has permitted major advances in the understanding of the dynamics and thermodynamics of nuclear matter [1, 2] and is still one of the most promising tools to constrain its equation of...
Isoscaling effect with
J. W. Lee for S
Korea University, Seoul, Korea
The mechanism of the fragmentation in heavy ion collision is studied with particle yields of light nuclei. In the thermal equilibrium view, the primary fragment yield can be predicted using the partition function of each fragment. However, the fragments...
The isospin dependence of in-medium nuclear effective interactions is a fundamental issue in nuclear physics and has broad ramifications in astrophysics. Its uncertainties, especially the difference of neutron-proton interactions in the isosinglet and isotriplet channels, affect significantly the density and momentum dependence of the isovector single-nucleon potential and nucleon-nucleon...
The CHIFAR experiment [1] was carried out at LNS in November 2019. Reactions between beams of 124Sn,124Xe and 112Sn, accelerated at 20 AMeV by the CS, and targets of 64Ni, 64Zn and 58Ni were studied by using the CHIMERA multi-detector [2] coupled to 10 telescopes of the FARCOS array [3]. The ten FARCOS telescopes, grouped in 5 couples, were arranged in a ring-like configuration covering about...
Pion spectral ratios and double ratios are measured for neutron rich 132Sn+124Sn and neutron deficient 108Sn+112Sn collisions. Both pi-/Pi+ single spectral ratios for the two systems and double ratios obtained by combining both systems can be described by a dcQMD calculations. These comparisons provide a correlated constraint on L and on the neutron-proton effect mass difference. This...
Clusters are the dominant products in heavy-ion collisions (HICs) in a wide energy range from the Fermi energy domain to higher energies of several hundred MeV/nucleon. Correlations in such highly excited nuclear many-body systems are of particular interest, and strong correlations can affect the global dynamical evolution of HICs. Also studies of EOS of symmetric and asymmetric nuclear matter...
Population and decay of states of 12C
G. Cardella(1), A. Bonasera(2)(3), N.S. Martorana(2)(4), L. Acosta(1)(5), E. De Filippo(1), E. Geraci(1)(4), B. Gnoffo(1)(4), C. Guazzoni(6), L.Lo Monaco(4), C. Maiolino(2), A. Pagano(1), E.V. Pagano(2), M. Papa(1), S. Pirrone(1), G. Politi(1)(4), F. Rizzo(2)(4), P. Russotto(2), D. V. Sicari(6), and M. Trimarchi(1)(7)
1 INFN sezione di Catania,...
The second 0
In this talk, I will review some recent achievements in the study of clustering in light and medium mass nuclei. In particular, I will discuss some results in the rush to the discovery of possible direct decays of the Hoyle state in 12C, that has been performed both by using nuclear reactions at low and medium energies. I will also discuss some results obtained in the analysis of 13C and 20Ne...
The use of Energy Density Functional (EDF) method within a relativistic framework showed, this last decades, that it can both describe the bulk properties of nuclei (radii, ground state energy, binding energy, ...) [1] as well as clusters formation[2]. The study of cluster structures allow for many applications ranging from
F. Risitano 1,2,* , L. Acosta 1,3 , G. Cardella 1 , E. De Filippo 1 , D. Dell’Aquila 4,5 , F. Favela 1,3 , E. Geraci 1,6 , B. Gnoffo 1,6 , I. Lombardo 1 , C. Maiolino 5 , N.S. Martorana 5,6 , A. Pagano 1 , E.V. Pagano 5 , M. Papa 1 , S. Pirrone 1 , G. Politi 1,6 , F. Rizzo 5,6 , P. Russotto 5 , A. Trifirò 1,2 , M. Trimarch i1,2
1) INFN-Sezione di Catania, Italy
2) Dipartimento MIFT,...
The formation of nuclear clusters constitutes an essential feature for the construction of global equation-of-state (EoS) tables. They emerge as many-body correlations, which can be
attributed to the nucleon-nucleon (NN) interaction, and exist at sub-saturation densities in nuclear matter. Phenomenological models that make use of energy density functionals (EDFs) offer a convenient approach...
Interpreting high-energy, astrophysical phenomena, such as supernova explosions or neutron-star collisions, requires a robust understanding of matter at supranuclear densities. However, our knowledge about dense matter explored in the cores of neutron stars remains limited. Fortunately, dense matter is not only probed in astrophysical observations, but also in terrestrial heavy-ion collision...
In this review, we seek to synthesize the current literature in terms of works that harness machine learning for the understanding of the nuclear EoS in astrophysics. Furthermore, we propose future areas of work at this exciting interdisciplinary nexus. Model types and approaches include regression, clustering, decision trees, ensemble models, and neural networks (computer vision). There are,...
I will argue that if black holes represent one the most fascinating implications of Einstein's theory of gravity, neutron stars in binary system are arguably its richest laboratory, where gravity blends with astrophysics and particle physics. I will discuss the rapid recent progress made in modelling these systems and show how the gravitational signal can provide tight constraints on the...
The exceptional progress of multi-messenger astronomy on different astrophysical sources of dense matter has very recently led to quantitative measurements of various properties of neutron stars, such as the correlation between mass and radius from X-ray timing with NICER and the tidal polarizability from gravitational wave LIGO/Virgo data. These observations, together with the plethora of...
Nuclear pasta, which is an inhomogeneous distribution of nuclear matter characterized by non-spherical clustered structures, is expected to occur in a narrow spatial region at the bottom of the inner crust of neutron stars, but the width of the pasta layer is strongly model dependent. In the framework of a compressible liquid-drop model, we use Bayesian inference to analyze the constraints on...
N.S. Martorana
Determination of impact parameter is a challenge for experimentalists because it cannot be measured directly. Using transport model simulations, it has been demonstrated that machine learning algorithms can infer impact parameter from experimental observables. However, unlike simulations, detection limitations such as geometric efficiencies and energy thresholds of the detector may affect the...
With the advent of new facilities for radioactive ion beams mainly rich in neutrons, like SPES @ LNL, FRAISE @ LNS and FAIR @ GSI just to give some examples, the detection of neutrons, in conjunction with charged particles, in Heavy on collisions with radioactive beams becomes mandatory. Neutron detection requires both high angular and energy resolutions. Consequently, the construction of new...
The radioactive ion (RI) beam accelerator facility called RAON is under construction in Korea. It will produce RI beams by both the ISOL and In-flight methods. One of the experimental facilities called KoBRA is expected to carry out nuclear astrophysics and nuclear structure experiments in the early phase of RAON. Several experiments using both stable and RI beams of tens of MeV/u are...
Proton induced quasi-free scattering is a tool of choice to probe the nuclear single particle structure. When dealing with radioactive beams in inverse kinematics, the use of liquid hydrogen targets is a very natural choice. In this talk I will describe two devices, MINOS and COCOTIER, which are used at RIBF RIKEN and GSI, respectively, to pursue the study of the structure of radioactive nuclei
NUPECC prizes given by M. Lewitowitz, chair of NUPECC