Autor: Guazzoni, P. - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Probing the symmetry energy at low density using observable from neck fragmentation
Autorzy:: Pirrone, S.
Grassi, L.
Baran, V.
Russotto, P.
Cardella, G.
Papa, M.
Auditore, L.
Grzeszczuk, A.
Trifirò, A.
Porto, F.
Piasecki, E.
Vigilante, M.
Colonna, M.
Acosta, L.
Zetta, L.
Trimarchi, M.
Minniti, T.
Guazzoni, P.
Płaneta, Roman
Skwira-Chalot, I.
Maiolino, C.
Siwek-Wilczyńska, K.
Rosato, E.
Wilczyński, J.
Lombardo, I.
Pop, A.
Agodi, C.
Geraci, E.
De Filippo, E.
Berceanu, I.
Gianì, R.
Rizzo, F.
Amorini, F.
Pagano, E. V.
Cap, T.
Verde, G.
Pagano, A.
Francalanza, L.
Politi, G.
La Guidara, E.
Han, J.
Lanzalone, G.
Quattrocchi, L.
Opis:: Semi-peripheral collisions of ^{64}Ni + ^{124}Sn in direct and inverse kinematics, at 35 A MeV incident energy, are studied to characterize the dynamical origin and align-ments properties of fragments emission at midrapidity. This emission is partly due to the fragmentation of a transient neck joining the projectile and target in the early stages of the reaction. Recently we exploited observable from neck fragmentation to constraint the density dependence of the symmetry energy. In this contribution we focus on the density evolution of the mid-rapidity source. An experimental survey is suggested to check if data are consistent with the formation of neck fragments in a dilute density region in contact with the projectile-like and target-like spectators at normal saturation density.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

Inne

na półce

Skocz do pozycji: 2.

Tytuł:: Correlations between emission timescale of fragments and isospin dynamics in ^{124}Sn+^{64}Ni and ^{112}Sn+^{58}Ni reactions at 35A MeV
Autorzy:: Lombardo, I.
Le Neindre, N.
D'Agostino, M.
Anzalone, A.
Wieleczko, J. P.
De Filippo, E.
Verde, G.
Gawlikowicz, W.
Vigilante, M.
Pop, A.
Lanzalone, G.
Bougault, R.
Skwira-Chalot, I.
Trimarchi, M.
Lanzanò, G.
Cavallaro, S.
Amorini, F.
Bruno, M.
Pagano, A.
Chatterjee, M. B.
Di Toro, M.
Frankland, J.
Pirrone, S.
Rizzo, F.
Geraci, E.
Wilczyński, J.
Płaneta, Roman
Auditore, L.
Galichet, E.
Porto, F.
Zipper, W.
Politi, G.
Cap, T.
La Guidara, E.
Russotto, P.
Berceanu, I.
Rosato, E.
Maiolino, C.
Rivet, M. F.
Chbihi, A.
Cardella, G.
Papa, M.
Schmidt, K.
Kowalski, S.
Zetta, L.
Siwek-Wilczyńska, K.
Trifirò, A.
Dayras, R.
Colonna, M.
Piasecki, E.
Borderie, B.
Guazzoni, P.
Baran, V.
Grzeszczuk, A.
Opis:: We present a new experimental method to correlate the isotopic composition of intermediate mass fragments (IMF) emitted at midrapidity in semiperipheral collisions with the emission timescale: IMFs emitted in the early stage of the reaction show larger values of ⟨N/Z⟩ isospin asymmetry, stronger angular anisotropies, and reduced odd-even staggering effects in neutron to proton ratio ⟨N/Z⟩ distributions than those produced in sequential statistical emission. All these effects support the concept of isospin “migration”, that is sensitive to the density gradient between participant and quasispectator nuclear matter, in the so called neck fragmentation mechanism. By comparing the data to a stochastic mean field (SMF) simulation we show that this method gives valuable constraints on the symmetry energy term of nuclear equation of state at subsaturation densities. An indication emerges for a linear density dependence of the symmetry energy.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

Artykuł

na półce

Skocz do pozycji: 3.

Tytuł:: Production cross sections for intermediate mass fragments from dynamical and statistical decay of projectile-like fragments in ^{124}Sn + ^{64}Ni and ^{112}Sn + ^{58}Ni collisions at 35A MeV
Autorzy:: Lanzanò, G.
Grzeszczuk, A.
Kowalski, S.
Berceanu, I.
Lanzalone, G.
Siwek-Wilczyńska, K.
Acosta, L.
Wieleczko, J. P.
Bruno, M.
Gawlikowicz, W.
Minniti, T.
Guazzoni, P.
Le Neindre, N.
Baran, V.
Piasecki, E.
Płaneta, Roman
D'Agostino, M.
Auditore, L.
Papa, M.
Maiolino, C.
Di Toro, M.
Cavallaro, S.
Borderie, B.
Rivet, M. F.
Schmidt, K.
Chatterjee, M. B.
Skwira-Chalot, I.
Trimarchi, M.
Cap, T.
Politi, G.
Rosato, E.
Verde, G.
Wilczyński, J.
Chbihi, A.
Zipper, W.
Cardella, G.
Pagano, E. V.
Rizzo, F.
Pagano, A.
Lombardo, I.
Colonna, M.
Gnoffo, B.
Porto, F.
De Filippo, E.
Pirrone, S.
Galichet, E.
Frankland, J.
Zetta, L.
Russotto, P.
Geraci, E.
Bougault, R.
Trifirò, A.
Vigilante, M.
Francalanza, L.
Quattrocchi, L.
Opis:: Background: In heavy-ion collisions at intermediate energies the production of light charged particles and intermediate mass fragments (IMFs) is due to different reaction mechanisms and different time scales, ranging from fast dynamical processes to statistical emission from the equilibrated system. Purpose: We compare the IMF statistical and dynamical emission probabilities in collisions of a neutron-rich ^{124}Sn + ^{64}Ni system and a neutron-poor ^{112}Sn + ^{58}Ni system at the laboratory energy of 35 A MeV. Method: The IMFs production mechanism in semiperipheral reactions has been investigated in our previous works. In this paper, the analysis is expanded for the same set of data and production cross sections have been evaluated for dynamical and statistical emission in a coherent way for light and heavy fragments. Results: The data analysis has evidenced a strong competition between dynamical and statistical emission mechanisms. Probability of the dynamical emission of IMFs is strongly influenced by the (N/Z) ratio of the colliding system. Conclusions: It is demonstrated that the statistical emission is equally probable for the two systems, while the dynamical emission is enhanced for the neutron-rich system, especially for heavy fragments (Z≥6). The observed effect points at a high sensitivity of the prompt-dynamical emission to the (N/Z) ratio of a given system.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego