Quantal diffusion description of multinucleon transfers in heavy-ion collisions

Ayik, S.
Yilmaz, B.
Yılmaz, Osman
Umar, A. S.
Employing the stochastic mean-field (SMF) approach, we develop a quantal diffusion description of the multi-nucleon transfer in heavy-ion collisions at finite impact parameters. The quantal transport coefficients are determined by the occupied single-particle wave functions of the time-dependent Hartree-Fock equations. As a result, the primary fragment mass and charge distribution functions are determined entirely in terms of the mean-field properties. This powerful description does not involve any adjustable parameter, includes the effects of shell structure, and is consistent with the fluctuation-dissipation theorem of the nonequilibrium statistical mechanics. As a first application of the approach, we analyze the fragment mass distribution in Ca-48 + U-238 collisions at the center-of-mass energy E-c.m. = 193 MeV and compare the calculations with the experimental data.


Quantal diffusion approach for multinucleon transfers in Xe plus Pb collisions
Ayik, S.; Yilmaz, B.; Yılmaz, Osman; Umar, A. S. (2019-07-01)
Employing a quantal diffusion description based on the stochastic mean-field approach, we analyze the mass distribution of the primary fragments in the collisions of the Xe-136 + Pb-208 system at the bombarding energy E-c.m. = 526 MeV. This quantal approach provides a good description of the primary fragment distribution without any adjustable parameter, including the effects of shell structure
Quantal description of nucleon exchange in a stochastic mean-field approach
Ayik, S.; YILMAZ TÜZÜN, ÖZGÜL; YILMAZ, BÜLENT; Umar, A. S.; GÖKALP, AHMET; Turan, Gürsevil; Lacroix, D. (2015-05-04)
The nucleon exchange mechanism is investigated in central collisions of symmetric heavy ions in the basis of the stochastic mean-field approach. Quantal diffusion coefficients for nucleon exchange are calculated by including non-Markovian effects and shell structure. Variances of fragment mass distributions are calculated in central collisions of Ca-40 + Ca-40, Ca-48 + Ca-48, and N-56 i+ Ni-56 systems.
Multinucleon transfer in Ni-58+Ni-60 and Ni-60+Ni-60 in a stochastic mean-field approach
Yilmaz, B.; Ayik, S.; Yılmaz, Osman; Umar, A. S. (2018-09-07)
The multinucleon exchange mechanism in Ni-58 + Ni-60 and Ni-60 + Ni-60 collisions is analyzed in the framework of the stochastic mean-field approach. The results of calculations are compared with the time-dependent random-phase approximation (TDRPA) calculations and the recent data of Ni-58 + Ni-60. A good description of the data and a relatively good agreement with the TDRPA calculations are found.
Multinucleon transfer in central collisions of U-238+U-238
Ayik, S.; YILMAZ, BÜLENT; YILMAZ TÜZÜN, ÖZGÜL; Umar, A. S.; Turan, Gürsevil (2017-08-14)
Quantal diffusion mechanism of nucleon exchange is studied in the central collisions of U-238 + U-238 in the framework of the stochastic mean-field (SMF) approach. For bombarding energies considered in this work, the dinuclear structure is maintained during the collision. Hence, it is possible to describe nucleon exchange as a diffusion process for mass and charge asymmetry. Quantal neutron and proton diffusion coefficients, including memory effects, are extracted from the SMF approach and the primary fragm...
Quantal description of spinodal instabilities in a symmetric nuclear matter
Acar Çakırca, Fatma; Yılmaz, Osman; Ayık, Şakir; Department of Physics (2017)
Spinodal instability mechanism and early development of density fluctuations for asymmetric hot nuclear matter produced in heavy-ion collisions are investigated in non-relativistic and relativistic stochastic mean-field approaches. In relativistic approach, a stochastic extension of the relativistic mean-field approximation based on non-linear Walecka model employed in a quantal framework. The mediator rho meson is added to the Walecka model in order to investigate the isospin dependence of the system. The gro...
Citation Formats
S. Ayik, B. Yilmaz, O. Yılmaz, and A. S. Umar, “Quantal diffusion description of multinucleon transfers in heavy-ion collisions,” PHYSICAL REVIEW C, pp. 0–0, 2018, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/32802.