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In the neutron-star crust, nonuniform structure of nuclear matter\char22{}called the ``pasta'' structure\char22{}is expected. From recent studies of giant flares in magnetars, these structures might be related to some observables and physical quantities of the neutron-star crust. To investigate the above quantities, we numerically explore the pasta structure with a fully three-dimensional geometry and study the properties of low-density nuclear matter, based on the relativistic mean-field model and the Thomas-Fermi approximation. We observe typical pasta structures for fixed proton number fraction and two of them for cold catalyzed matter. We also discuss the crystalline configuration of ``pasta.''

We study the hadron-quark mixed phase in protoneutron stars, where neutrinos are trapped and lepton number becomes a conserved quantity besides the baryon number and electric charge. Considering protoneutron-star matter as a ternary system, the Gibbs conditions are applied together with the Coulomb interaction. We find that there no crystalline (``pasta'') structure appears in the regime of high lepton-number fraction; the size of pasta becomes very large and the geometrical structure becomes mechanically unstable due to the charge screening effect. Consequently the whole system is separated into two bulk regions like an amorphous state, where the surface effect is safely neglected. There, the local charge neutrality is approximately attained, so that the equation of state is effectively reduced to the one for a binary system. Hence, we conclude that there is no possibility for the density discontinuity to appear in protoneutron-star matter, which is a specific feature in a pure system. These features are important when considering astrophysical phenomena such as supernova explosions or radiation of the gravitational wave from protoneutron stars.

We propose a model based on quantum molecular dynamics (QMD) incorporated with a statistical decay model (SDM) to describe various nuclear reactions in a unified way. In this first part of the work, the basic ingredients of the model are defined and the model is applied systematically to the nucleon- (N-)induced reactions. It has been found that our model can give a remarkable agreement in the energy-angle double differential cross sections of (N,${\mathit{xN}}^{\ensuremath{'}}$) type reactions for incident energies from 100 MeV to 3 GeV with a fixed parameter set. A unified description of the three major reaction mechanisms of (N,${\mathit{xN}}^{\ensuremath{'}}$) reactions, i.e., compound, preequilibrium, and spallation processes, is given with our model.

We study the hadron-quark phase transition, taking into account the finite-size effects for neutron star matter. For the hadron phase, we adopt a realistic equation of state within the framework of the Brueckner-Hartree-Fock theory. For the quark phase, we apply the Dyson-Schwinger method. The properties of the mixed phase are clarified by considering the finite-size effects. We find that, if the surface tension is strong enough, the equation of state becomes to be close the one with the Maxwell condition, though we properly adopt the Gibbs conditions. This result is qualitatively the same with the one by the use of the simple bag model. We also find that the mass-radius relation by the EoS is consistent with the observations of massive neutron stars., Comment: 4 pages, 2 figures, the proceeding for "Nuclear Physics in Astrophysics VI"

Inside neutron stars, the hadron-quark mixed phase is expected during the first order phase transition from the hadron phase to the quark phase. The geometrical structure of the mixed phase strongly depends on the surface tension at the hadron-quark interface. We evaluate the shear modulus which is one of the specific properties of the hadron-quark mixed phase. As an application, we study shear oscillations due to the hadron-quark mixed phase in neutron stars. We find that the frequencies of shear oscillations depend strongly on the surface tension; with a fixed stellar mass, the fundamental frequencies are almost proportional to the surface tension. Thus, one can estimate the value of surface tension via the observation of stellar oscillations with the help of the information on the stellar mass., accepted for publication in NPA

We first explore the liquid-gas mixed phase in a bulk calculation, where two phases coexist without the geometrical structures. In the case of symmetric nuclear matter, the system behaves congruently, and the Maxwell construction becomes relevant. For asymmetric nuclear matter, on the other hand, the phase equilibrium is no more attained by the Maxwell construction since the liquid and gas phases are non-congruent; the particle fractions become completely different with each other. One of the origins of such non-congruence is attributed to the large symmetry energy. Subsequently we explore the charge-neutral nuclear matter with electrons by fully applying the Gibbs conditions to figure out the geometrical (pasta) structures in the liquid-gas mixed phase. We emphasize the effects of the surface tension and the Coulomb interaction on the pasta structures. We also discuss the thermal effects on the pasta structures., proceedings of PANIC 2011

The usual definition of the prior(post) interaction $V(V^\prime )$ between projectile and target (resp. ejectile and residual target) being contradictory with full antisymmetrization between nucleons, an explicit antisymmetrization projector ${\cal A}$ must be included in the definition of the transition operator, $ T\equiv V^\prime{\cal A}+V^\prime{\cal A}GV. $ We derive the suitably antisymmetrized mean field equations leading to a non perturbative estimate of $T$. The theory is illustrated by a calculation of forward $\alpha$-$\alpha$ scattering, making use of self consistent symmetries., Comment: 30 pages, no figures, plain TeX, SPHT/93/144

The quark-hadron mixed phase ("pasta" phase) with hyperons and neutrinos is studied at finite temperature. We take into account the finite-size effects to the mixed phase, imposing the Gibbs conditions. As a result, we find that the mixed phase becomes unstable at finite temperature. The presence of neutrinos makes the pasta structures more unstable. These results suggest that the quark-hadron mixed phase will appear during the evolution of protoneutron stars after supernova explosions.

The second‐order effects (SOE) including a pole contribution of the Λ(1405) (Λ*) and range terms on the structure of multi‐antikaonic nuclei are investigated in a relativistic mean‐field theory coupled with the nonlinear effective chiral Lagrangian. It is shown that, due to the attractive interaction from the Λ*‐pole contribution, the K− mesons and the protons are more attracted each other than the case without the SOE. On the other hand, the density distribution for neutron is pushed outward due to the repulsive effect from the range terms. The SOE on the formation of the bound state of K− mesons are also discussed associated with modification of relevant kaonic modes in a dense medium.

Kaon production is studied using a Boltzmann type of equation that takes into account three­ nucleon collisions. Our approach reproduces fairly well existing p-nucleus data. The importance of cooperative process in subthreshold particle production is suggested in comparison between kaon yields from p and d induced reactions. Kaon production has been proposed 1H ) to study the initial stage of a nucleus­ nucleus collision_ Indeed, due to their long mean free paths in the nuclear environ­ ment, kaons could be used as probes of the dense and highly excited system formed during the collision of two nuclei. This is not true, for example, for pions which interact strongly with the nucleus, resulting in losing memory of the initial stage of the collision due to reabsorption and/or rescattering effects. However, there are some problems when one deals with kaon production. The most serious one is that the K-elementary production cross section is not well known either experimentally or theoretically.4) The scarce existing data for the elementary process show discrep­ ancies between various groups.1),4),5) For example, the proton-proton data at 2.5 GeV differs by a factor of two between two different experimental groups! This fact, of course, makes a comparison between theory and experiment impossible at an absolute level. In fact, changes in the elementary cross section can change the theoretical production in p-nucleus and nucleus-nucleus collisions by a factor 2~4. Another source of uncertainty in the calculations is the unknown Equation Of State (EOS) of nuclear matter. In Ref. 6) it was shown that the kaon yield obtained in nucleus­ nucleus collisions changes of a factor 2 ~ 3 when the compressibility of the EOS is changed from a soft (200 Me V) to a stiff one. This is due to the different values of compression obtained in the two cases which causes a smaller number of nucleon­ nucleon (N-N) collisions for the stiff EOS. To avoid this problem one could use a p or a d projectile. For such collisions there is little change in the density. However, the EOS is strongly momentum dependent at relativistic energies. 7 ) The momentum dependence of the EOS may strongly affect the kaon yield even for the proton beams_ 2 ) T4e ambiguities in the elementary process and the nuclear EOS do not change the main result of our work since we are interested in the increase of the kaon yield in d induced reactions compared to p-nucleus collisions. In fact, we find that for the p+12C system the kaon yield is a factor 1000 or more smaller than the yield for the d +12C *) Permanent address: Laboratorio Nazionale del Sud, INFN, viale A. Doria ang. via S. Sofia, 95123

We investigate the properties of nuclear matter at the first-order phase transitions such as liquid-gas phase transition and hadron-quark phase transition. As a general feature of the first-order phase transitions of matter consisting of many species of charged particles, there appears a mixed phases with geometrical structures called ``pasta'' due to the balance of the Coulomb repulsion and the surface tension between two phases. The equation of state (EOS) of mixed phase is different from the one obtained by a bulk application of the Gibbs conditions or by the Maxwell construction due to the effects of the non-uniform structure. We show that the charge screening and strong surface tension make the EOS close to that of the Maxwell construction. The thermal effects are elucidated as well as the above finite-size effects., Presentation at NFQCD 2010 at Yukawa Inst. TO appear on Prog. Theor. Phys. Suppl

Liquid-gas phase transition is discussed in warm asymmetric nuclear matter. Some peculiar features are figured out from the viewpoint of the basic thermodynamics about the phase equilibrium. We treat the mixed phase of the binary system based on the Gibbs conditions. When the Coulomb interaction is included, the mixed phase is no more uniform and the sequence of the pasta structures appears. Comparing the results with those given by the simple bulk calculation without the Coulomb interaction, we extract specific features of the pasta structures at finite temperature.

Recently, the central source of Cassiopeia A (Cas A) has been observed, which indicates that the star has large mass and high effective temperature. We suspect that the compact object cools by the standard neutrino emission. We assume that the compact object contains quark matter with colour superconductivity and calculate cooling curves. Considering the Quark‐Hadron Mixed Phase, we obtain cooling curves which are found to be consistent with the observations.

The structure of multi‐antikaonic nuclei (MKN) is investigated in a relativistic mean‐field theory coupled with the nonlinear K− field by the use of effective chiral Lagrangian. The effects of the Λ(1405) range terms on the structure of the MKN are taken into account. It is shown that baryon number density exceeds three times the normal saturation density in the central region of the MKN that a neutron skin structure becomes remarkable as the number of the embedded K− mesons increases. The similarity difference between the MKN kaon condensation in neutron stars are discussed.

We study the hadron‐quark phase transition with finite size effects at a finite temperature. For the hadron phase, we adopt a realistic equation of state with the Brueckner‐Hartree‐Fock theory including hyperons. Properties of the mixed phase are clarified by considering the finite size effects under the Gibbs conditions. We find that the equation of state gets closer to that given by the Maxwell construction. We also find that the equation of state becomes softer than that at a zero temperature for some density region. Moreover, the number of hyperons is suppressed by the presence of quarks. These are characteristic features of the hadron‐quark mixed phase, and should be important for many astrophysical phenomena such as mergers of binary neutron stars.

Quantum Molecular Dynamics method is combined with multi-step statistical decay calculation and they are applied to the investigation of fragment mass distribution and the reaction time scale in intermediate energy heavy-ion collisions. The fragment mass distributions in 14N(35 MeV /u)+ C , and 4°Ar(44 MeV/u)+ Al collisions are well reproduced by our framework. We discuss the time evolution of fragment mass yield and contribution of statistical decay process in these two systems.

Two-nucleon collision process is incorporated into the antisymmetrized version of the molecular dynamics by utilizing the technique and the concept developed in the time-dependent cluster model. This newly formulated method of microscopic simulation of the heavy ion reaction can describe quantum mechanical features such as shell effects, since it treats the time development of the system wave function. We also propose a new prescription by which we can avoid the spurious zero-point energies of center-of-massmotion of fragment wave packets. The fragment production cross sections of the 12C+12C reaction at 28.7 MeV /nucleon are analyzed by this new method. It is shown that the basic feature of the data including the large cross section of a-particle is reproduced well by the·theory. Furthermore we show that the data are reproduced very well when we take into account the statistical cascade decays of the produced fragments, which verifies the great usefulness of the new microscopic simulation framework.

In supernova cores, nuclear "pasta" phases such as triangular lattice of rod-like nuclei and layered structure of slab-like nuclei are considered to exist. However, it is still unclear whether or not they are actually formed in collapsing supernova cores. Using {\it ab-initio} numerical simulations called the Quantum Molecular Dynamics (QMD), we here solve this problem by demonstrating that a lattice of rod-like nuclei is formed from a bcc lattice by compression. We also find that, in the transition process, the system undergoes zigzag configuration of elongated nuclei, which are formed by a fusion of two original spherical nuclei., Comment: 4 pages, 3 figures, to appear in Phys. Rev. Lett. as an Editors' Suggestion

The effects of the K−K interactions on properties of the multi‐antikaonic nuclei (MKN), in which several K− mesons are embedded to form deeply bound states, are investigated based on chiral symmetry combined with the relativistic mean‐field theory. The K−K interactions originate from two contributions: One is the contact interaction between antikaons inherent in chiral symmetry, and the other is the one generated through coupling between the K− and meson mean fields. It is shown that the former leads to saturation of not only nuclear density profiles but also the strength of the K− field at the center of the MKN and that both parts of the K−K repulsive interactions have a large contribution to the ground state energy of the K− mesons and binding energy of the MKN as the number of the embedded K− mesons increases.

We study the hadron-quark phase transition with the finite size effects at finite temperature. For the hadron phase, we adopt a realistic equation of state in the framework of the Brueckner-Hartree-Fock theory including hyperons. The properties of the mixed phase are clarified by considering the finite size effects under the Gibbs conditions. We find that the equation of state becomes softer than that at zero-temperature for some density region. We also find that the equation of state gets closer to that given by the Maxwell construction. Moreover, the number of hyperons is suppressed by the presence of quarks. These are characteristic features of the hadron-quark mixed phase, and should be important for many astrophysical phenomena such as mergers of binary neutron stars., Comment: 8 pages, 13 figures. accepted to Phys. Rev. D

We investigate the properties of nuclear matter at the first-order phase transitions (FOPT) such as liquid-gas phase transition, kaon condensation, and hadron-quark phase transition. As a general feature of the FOPT of matter consisting of many species of charged particles, there appears a mixed phases with regular structures called "pasta" due to the balance of the Coulomb repulsion and the surface tension between two phases. The equation of state (EOS) of mixed phase is different from those obtained by a bulk application of Gibbs conditions or by the Maxwell construction due to the effects of the non-uniform structure. We show that the charge screening and strong surface tension make the EOS close to that of the Maxwell construction., Proceedings for the 6th Japan-Italy symposium on Heavy Ion Physics, Tokai, Japan, 11-15th Nov. 2008. to appear on AIP Conference Proceedings

The direct and semi-direct (DSD) components of the neutron capture cross sections are calculated for a series of tin isotopes by employing a single-particle potential (SPP) that gives a good reproduction of the known single-particle energies (SPEs) over a wide mass region. The results are compared with the Hauser-Feshbach (HF) contribution in the energy region of astrophysical interest. The calculated result shows that the HF component drops off rapidly for isotope $^{132}\mathrm{Sn}$ and toward more neutron-rich ones, whereas the DSD component decreases only smoothly and eventually becomes dominant. This result is consistent with those of previous studies, but the dependence of the DSD cross section on the target mass number is a feature of the present SPP that gives a smooth variation of SPEs. As a consequence, the direct portion of the DSD component gives the largest contribution to the total ($n,\ensuremath{\gamma}$) cross section for neutron-rich isotopes below a few MeV. Therefore, the direct capture process modifies the astrophysical ($n,\ensuremath{\gamma}$) reaction rates to a great extent. The semi-direct component, however, gives a negligible contribution to the astrophysical reaction rates, but its impact is significant above several MeV. The reason for the difference in isotopic dependence between the HF and DSD components is discussed, and its implication for $r$-process nucleosynthesis is given.

Properties of multi-antikaonic nuclei (MKN), where several numbers of $K^-$ mesons are bound, are studied in the relativistic mean-field model, combined with chiral dynamics for kaonic part of the thermodynamic potential. The density profiles for nucleons and $K^-$ mesons, the single particle energy of the $K^-$ mesons, and binding energy of the MKN are obtained. The effects of the $\bar K-\bar K$ interactions on these quantities are discussed in comparison with other meson ($\sigma$, $\omega$, and $\rho$)-exchange models. It is shown that the $\bar K-\bar K$ interactions originate from two contributions: One is the contact interaction between antikaons inherent in chiral symmetry, and the other is the one generated through coupling between the $K^-$ and meson mean fields. Both effects of the $\bar K-\bar K$ repulsive interactions become large on the ground state properties of the MKN as the number of the embedded $K^-$ mesons increases. A relation between the multi-antikaonic nuclei and kaon condensation in infinite and uniform matter is mentioned., Comment: 27 pages, 13 figures

The quantum molecular dynamic method is used to study the fusion reaction in the $^{16}\mathrm{O}$${+}^{16}$O system and its fade out with the increase of the incident energy. It is shown that without two-nucleon collisions there appears the so-called fusion window, as in the time-dependent Hartree-Fock approach, while with the inclusion of two-nucleon collisions the low partial wave cutoff in fusion disappears. The fade out of the fusion process with the increase of the incident energy is found to be due to the increase of the cross sections mainly of the incomplete fusion process in the whole range of the impact parameter and partly of the deep-inelastic-collision--like process in the peripheral region. The calculated fusion cross section as a function of incident energy is shown to be in good accordance with experiments.

We investigate the properties of the hadron-quark mixed phase in compact stars using a Brueckner-Hartree-Fock framework for hadronic matter and the MIT bag model for quark matter. We find that the equation of state of the mixed phase is similar to that given by the Maxwell construction. The composition of the mixed phase, however, is very different from that of the Maxwell construction; in particular, hyperons are completely suppressed., Invited talk at "Exotic States of Matter 2007 (EXOCT2007)", Catania, June 10-19, 2007

We investigate the non-uniform structures and the equation of state (EOS) of nuclear matter in the context of the first-order phase transitions (FOPT) such as liquid-gas phase transition, kaon condensation, and hadron-quark phase transition. During FOPT the mixed phases appear, where matter exhibits non-uniform structures called ``Pasta'' structures due to the balance of the Coulomb repulsion and the surface tension between two phases. We treat these effects self-consistently, properly taking into account of the Poisson equation and the Gibbs conditions. Consequently, they make the EOS of the mixed phase closer to that of Maxwell construction due to the Debye screening. This is a general feature of the mixed phase consisting of many species of charged particles., Comment: Invited talk at "Nuclear Dynamics in Heavy-ion Reactions and Neutron Stars", Beijing, July 10-14, 2007

We discuss the properties of the hadron-quark mixed phase in compact stars using a realistic equation of state of hyperonic matter and the MIT bag model. We find that the equation of state of the mixed phase is similar to that given by the Maxwell construction, but that the mixed phase becomes mechanically unstable if the surface tension of the interface between the two pure phases is strong enough. The composition of the mixed phase is very different from that of the Maxwell construction; in particular, hyperons are completely suppressed., Comment: 11 pages, 5 figures

We study the charge screening effect in the hadron-quark mixed phase. By including the charge screening effect, rearrangement of charged particles occurs and some part becomes locally charge-neutral. As a result the equation of state for the mixed phase becomes close to that given by the Maxwell construction, which means that the Maxwell construction would effectively gain the physical meaning again even in the system with two or more chemical potentials. We also discuss the interplay of the surface tension and the Coulomb interaction. Both effects would restrict the region of the mixed phase in the core of hybrid stars., Comment: Proceeding of 29th Johns Hopkins Workshop: "Strong Matter in the Heavens", to be published in Proceedings of Science, PoS(JHW)019

We show that the hadron-quark mixed phase is restricted to narrow range of baryon chemical potential by the charge screening effect. Accordingly the mixed phase expected in hadron-quark hybrid stars should be narrow. Although the screening would not have large effect in bulk properties of the star such as mass or radius, it change the internal structure of the star very much, which may be tested by the cooling curve, glitch phenomena or gravitational waves., Comment: Proceeding of the "Origin of Matter and Evolution of Galaxies 2005 (OMEG05)"

We study the hadron-quark phase transition in a molecular dynamics (MD) of quark degrees of freedom. The hadron state at low density and temperature, and the deconfined quark state at high density and temperature are observed in our model. We investigate the equations of state and draw the phase-diagram at wide baryon density and temperature range. We also discuss the transport property, e.g. viscosity, of $q\bar{q}$ matter. It is found that the ratio of the shear viscosity to the entropy density is less than one for quark matter., Poster presentation at Quark Matter 2005

Nonuniform structures of mixed phases at the first-order phase transition to charged kaon condensation are studied using a density functional theory within the relativistic mean-field model. Including electric field effects and applying the Gibbs conditions in a proper way, we numerically determine density profiles of nucleons, electrons, and condensed kaons. Importance of charge screening effects is elucidated and thereby we show that the Maxwell construction is effectively justified. Surface effect is also studied to figure out its effect on the density profiles.

There are many common features in nuclear data for energy applications and nuclear cosmology/astrophysics, especially the neutron‐capture nucleosynthesis. Therefore it is a natural consequence to think that many of the tools that we have developed for the conventional nuclear‐data applications can be applied for a development of a database for nuclear cosmology/astrophysics. However, there are also many features that are uncommon to these fields, so new development is necessary when we think about a database for nuclear cosmology and astrophysics. Such new development will then give us a new horizon for the conventional nuclear data activities as well. In this paper we will show the present status of our activities in this direction, putting emphasis on data relevant to neutron capture nucleosynthesis, namely s‐ and r‐processes.

The Coulomb interaction effect and the surface effect are consistently taken into account in the hadron-quark mixed phase. These two finite-size effects greatly change the properties of the mixed phase and restrict its density region. In particular, the charge screening effect and the rearrangement of the charged particles are elucidated. Keeping the Gibbs conditions throughout the numerical procedure, we show the Maxwell construction effectively regain the physical meaning and the equation of state becomes similar to that given by the Maxwell construction., Comment: 16 pages, 12 figures

We study stability and structure of quark matters as a function of density in a framework of molecular dynamics (MD). Using appropriate effective interactions and the frictional cooling method, we search for the minimum energy of the system. Transition from confined to deconfined phase is observed at densities of 2 -- 3$\rho_0$, where $\rho_0$ is the nuclear matter saturation density. The $uds$ matter becomes more stable than the charge-neutral $ud$ matter at 3$\rho_0$, but the $udd$ matter is the most stable even at high density., Comment: Proceedings for NPDC18,23-29,August,2004

Calculations of equilibrium properties of dense matter predict that at subnuclear densities nuclei can be rodlike or slablike. To investigate whether transitions between phases with non-spherical nuclei can occur during the collapse of a star, we perform quantum molecular dynamic simulations of the compression of dense matter. We have succeeded in simulating the transitions between rodlike and slablike nuclei and between slablike nuclei and cylindrical bubbles. Our results strongly suggest that non-spherical nuclei can be formed in the inner cores of collapsing stars., 4 pages, 4 figures, final version published in Phys. Rev. Lett., high-res figures can be seen at http://www.nordita.dk/~gentaro/research/figs

Using the density functional theory (DFT) with the relativistic mean field (RMF) model, we study the non-uniform state of nuclear matter, ``nuclear pasta''. We self-consistently include the Coulomb interaction together with other interactions. It is found that the Coulomb screening effect is significant for each pasta structure but not for the bulk equation of state (EOS) of the nuclear pasta phase.

The Coulomb screening effect and the finite-size effect such as surface tension are figured out in the hadron-quark deconfinement phase transition. We study the mixed phase of the quark droplets immersed in hadron matter. We see that the droplet phase is mechanically unstable if the surface tension is strong enough. Once the Coulomb potential is properly taken into account, we could effectively satisfy the condition for charge chemical equilibrium in the Maxwell construction. As a result, we suggest the Maxwell construction revives the physical meaning effectively., Comment: 4 pages, 4figures, proceeding of Phase Transitions in Strongly Interacting Matter 18th International Nuclear Physics Divisional Conference of the EPS (NPDC18)Europhysics Conference

Coherent and incoherent dipolar $\ensuremath{\gamma}$-ray emission is studied in a fully dynamical approach by means of the constrained molecular dynamics model. The study is focused on the system ${}^{40}\mathrm{Ca}{+}^{48}\mathrm{Ca}$ for which recently experimental data have been collected at 25 MeV/nucleon. The approach allows us to explain the experimental results in a self-consistent way without using statistical or hybrid models. Moreover, calculations performed at higher energy show interesting correlations between the fragment formation process, the degree of collectivity, and the coherence degree of the $\ensuremath{\gamma}$-ray emission process.

Non-uniform structures of nuclear matter are studied in a wide density-range. Using the density functional theory with a relativistic mean-field model, we examine non-uniform structures at sub-nuclear densities (nuclear ``pastas'') and at high densities, where kaon condensate is expected. We try to give a unified view about the change of the matter structure as density increases, carefully taking into account the Coulomb screening effects from the viewpoint of first-order phase transition., Comment: Presented at "Tours Symposium on Nuclear Physics V"

We investigate the formation and the decay of heavy systems which are above the fission barrier. By using a microscopic simulation of constraint molecular dynamics (CoMD) on Au+Au collision, we observe composite states stay for very long time before decaying by fission.

The 112Sn+58Ni and 124Sn+64Ni systems at 35 MeV/nucleon have studied by means of the recently proposed Constrained Molecular Dynamics model (CoMD). Different aspects concerning the central and mid‐peripheral collisions are put in evidence. In particular asymmetry distributions of the produced cluster are discussed.