Impact of tensor forces on quasifission product yield distributions

TL;DR

This study uses microscopic TDHF theory to analyze how tensor forces affect quasifission product yields in heavy-ion collisions, revealing that tensor interactions influence shell effects and fragment distributions depending on the interaction parametrization.

Contribution

It provides new insights into the role of tensor forces in quasifission processes and compares different effective interaction parametrizations to understand their impact on fragment distributions.

Findings

Tensor forces affect shell effects in quasifission yields.

Different interaction parametrizations show varying shell effect prominence.

Shell effects are sensitive to specific regions of the tensor coupling constant space.

Abstract

We employ the microscopic time-dependent Hartree-Fock (TDHF) theory to study the 48Ca+249Bk and 48Ti+238U systems, taking into account the dependence on orientation for deformed nuclei and full range of impact parameters. By analyzing fragment distributions of neutron and proton numbers, we assess the influence of different isoscalar and isovector tensor coupling constants of the effective nucleon-nucleon interaction. The quasifission yield distributions of 48Ca + 249Bk collision system utilizing SLy5t and T31 parametrizations exhibit more pronounced spherical shell effects compared to those using SLy5, T44 and T62 sets. Furthermore, within each parametrization group, the distributions for SLy5t and T31 are closely aligned, as are those for SLy5, T44, and T62. Similarly, the yield distributions for the 48Ti + 238U system using SLy5t and T31 also reflect the more pronounced spherical shell effects relative to SLy5 and T62, while the charge distribution shows much better agreement with experimental results for the SLy5t and T62 parametrizations compared to SLy5 and T31. The yield distributions for the 48Ca+249Bk and 48Ti+238U systems, when compared across the SLy5, SLy5t, T31, T44, and T62 parametrizations, indicate that the influence of tensor forces on quasifission fragments is reflected in the prominence of shell effects. This influence appears to be sensitive only in specific regions within the isoscalar and isovector coupling constant parameter space. In the 48Ti + 238U system, the prominence of shell effects is manifested not only through shifts in peak positions but also through narrower yield distributions.