Investigation of the freeze-out configuration in the ^{197}Au + ^{197}Au reaction at 23 A MeV

According to the model predictions, observation of toroidal objects is expected in collisions of heavy ion at low incident energies. Comparison between experimental data and model predictions which may indicate the formation of flat/toroidal nuclear systems is shown

Competition between dynamical and sequential reaction channels in ^{197}Au+^{197}Au collisions at a bombarding energy of 23A MeV

Competition between the two reaction channels: sequential breakup and neck fragmentation has been studied in peripheral and semi-peripheral collisions of the 197 Au+ 197 Au system at bombarding energy of 23A MeV. It was found that the emission of heavy (A < 50) neck-originating fragments occurs in about 22% of ternary breakup events, making this reaction channel highly competitive with the sequential breakup of the projectile- or target-like fragment (78% of events)

Fusion-fission probabilities, cross sections, and structure notes of superheavy nuclei

Fusion – fission probabilities in the synthesis of heaviest elements are discussed in the context of the latest experimental reports. Cross sections for superheavy nuclei are evaluated using the “Fusion by Diffusion” (FBD) model. Predictive power of this approach is shown for experimentally known Lv and Og isotopes and predictions given for Z = 119, 120. Ground state and saddle point properties as masses, shell corrections, pairing energies, and deformations necessary for cross-section estimations are calculated systematically within the multidimensional microscopic-macroscopic method based on the deformed Woods-Saxon single-particle potential. In the frame of the FBD approach predictions for production of elements heavier than Z = 118 are not too optimistic. For this reason, and because of high instability of superheavy nuclei, we comment on some structure effects, connected with the K-isomerism phenomenon which could lead to a significant increase in the stability of these systems

Fusion-fission probabilities, cross sections, and structure notes of superheavy nuclei

Fusion – fission probabilities in the synthesis of heaviest elements are discussed in the context of the latest experimental reports. Cross sections for superheavy nuclei are evaluated using the “Fusion by Diffusion” (FBD) model. Predictive power of this approach is shown for experimentally known Lv and Og isotopes and predictions given for Z = 119, 120. Ground state and saddle point properties as masses, shell corrections, pairing energies, and deformations necessary for cross-section estimations are calculated systematically within the multidimensional microscopic-macroscopic method based on the deformed Woods-Saxon single-particle potential. In the frame of the FBD approach predictions for production of elements heavier than Z = 118 are not too optimistic. For this reason, and because of high instability of superheavy nuclei, we comment on some structure effects, connected with the K-isomerism phenomenon which could lead to a significant increase in the stability of these systems

Isospin effects on reaction dynamics at Fermi energies

The study of nuclei properties and of collision dynamics is a very active research field whose result have implications in different domains as for example astrophysics. The present and future facilities delivering radioactive ion beams with high intensity allow to extend these studies in the region far from the stability valley. New insight has thus been found on the effects of neutron richness on reaction mechanisms as well as on nuclear structure and nuclear matter properties, as for instance, the role of symmetry energy term of the nuclear Equation of State. The presence of diverse reaction products demands for highly performing and very specialized devices, also able to disentangle among different mechanisms, from fast dynamical processes to statistical emission from equilibrated sources. Numerous studies of the effects of N/Z ratio on fusion and associated processes can be found at different energies, together with many examples of the influence of neutron richness on the reaction time scale and the competition between equilibrated and prompt processes. A survey of very recent findings obtained with the CHIMERA and FARCOS devices is presented

The Polish School of Argumentation:A Manifesto

Building on our diverse research traditions in the study of reasoning, language and communication, the Polish School of Argumentation integrates various disciplines and institutions across Poland in which scholars are dedicated to understanding the phenomenon of the force of argument. Our primary goal is to craft a methodological programme and establish organisational infrastructure: this is the first key step in facilitating and fostering our research movement, which joins people with a common research focus, complementary skills and an enthusiasm to work together. This statement—the Manifesto—lays the foundations for the research programme of the Polish School of Argumentation

Aligned ternary partitioning of the ^{197}Au+^{197}Au system at 23 A MeV beam energy

Ternary partitions of the ^{197}Au+^{197}Au system in collisions at 23 A MeV beam energy have been studied. It is observed that the mass number distribution of the lightest fragments, called intermediate mass fragments (IMF), extends up to mass numbers corresponding to partitions into three comparable fragments. The lightest IMFs of A_{IFM} 30) definitely originate from sequential (but not equilibrated) decay of the primary projectile-like fragments (PLF*) (or target-like fragments (TLF*)). The decaying system evidently keeps memory of the neck configuration and consequently the IMFs are emitted collinearly either from the neck side or from the opposite side along the separation axis (polar emission). The new intriguing process of the polar emission dominates for IMFs of A_{IMF} > 50

Isospin effects on reaction dynamics at Fermi energies

International audienceThe study of nuclei properties and of collision dynamics is a very active research field whose result have implications in different domains as for example astrophysics. The present and future facilities delivering radioactive ion beams with high intensity allow to extend these studies in the region far from the stability valley. New insight has thus been found on the effects of neutron richness on reaction mechanisms as well as on nuclear structure and nuclear matter properties, as for instance, the role of symmetry energy term of the nuclear Equation of State. The presence of diverse reaction products demands for highly performing and very specialized devices, also able to disentangle among different mechanisms, from fast dynamical processes to statistical emission from equilibrated sources. Numerous studies of the effects of N/Z ratio on fusion and associated processes can be found at different energies, together with many examples of the influence of neutron richness on the reaction time scale and the competition between equilibrated and prompt processes. A survey of very recent findings obtained with the CHIMERA and FARCOS devices is presented