The European Physical Journal A最新文献

Neutron transfer cross sections for ⁷Li+²⁰⁵Tl system were measured near Coulomb barrier energies using online (gamma )-ray detection technique. One neutron stripping, two neutron stripping, and one neutron pickup cross sections have been extracted and are compared with the Coupled Reaction Channel (CRC) calculations. The systematics of one and two neutron stripping and pickup cross sections with a ⁷Li projectile on several targets show an approximate universal behaviour. A comparison of integrated neutron transfer cross sections with complete and incomplete fusion cross sections available with ⁷Li projectile is presented to understand the systematic behaviour. The neutron transfer along with cumulative sum of complete and incomplete fusion was found to explain the estimated reaction cross section in ⁷Li+²⁰⁵Tl system.

For the even nuclei of (^{204-208})Rn, (^{214-218})Ra and (^{232-234})U, the simultaneous description of charge distribution and total kinetic energy are studied within the scission-point model. The calculated data are compared with experimental data from the literature. Correlations between these observables and other quantities of interest are analysed.

The total reaction cross sections for systems with medium–heavy-mass range targets of Sn isotopes including ¹¹⁶Sn, ¹¹⁸Sn, ¹²⁰Sn, and ¹²⁴Sn, along with different projectiles ranging from tightly bound to weakly bound and halo, were taken from the literature and compared by reducing them to eliminate trivial effects due to different sizes and different Coulomb barriers. In addition, for all the systems considered, one-channel calculations accounting only for fusion were performed to study the quantitative effect of the direct reaction channels on the total reaction cross section.

The resonant (^{14})N+(alpha ) particle scattering was studied in the (^{18})F excitation region from 6.5 to 9 MeV at Astana cyclotron using the TTIK approach. The excitation functions for the elastic (^{14})N+(alpha ) scattering were analyzed in the framework of R matrix calculations. The observed strong alpha cluster structure in (^{18})F is compared with that in (^{18})O. While the general agreement of the structure in both nuclei is confirmed, a striking difference for l = 4 resonances is found. The experimental results are compared with configuration interaction calculations.

Silicon isotopic ratios measured in meteoritic presolar grains can provide useful information about the nucleosynthesis origin of these isotopes if the rates of nuclear reactions responsible for their production are known. One of the key reactions determining the Si isotopic abundances is (^{29})Si(p,(gamma ))(^{30})P. Its reaction rate is not known with sufficient precision due in part to some ambiguous resonance strength values. In the present work, the strength of the (E_textrm{p}) = 416.9 keV resonance has been measured with high precision using the activation technique. The new strength of (omega gamma = 219 pm ) 16 meV can be used in updated reaction rate estimations and astrophysical models.

We present a computation of triply-heavy baryons on a quantum computer, employing the Cornell quark model in line with the earlier quarkonium work of Gallimore and Liao. These baryons are some of the most interesting Standard Model particles which have not yet been detected, as they bear on the short range (colour) behaviour of the nuclear force. The spectrum here obtained is compatible with predictions from earlier works, with our uncertainty dominated by traditional few-body approximations (size of the variational basis, center of mass recoil, parameter estimation...) and not by the statistical error from the quantum computer (deployed here as a small diagonalizer), which turns out to be negligible with respect to the other sources of uncertainty, at least in the present unsophisticated few-body approximation. We have also substituted one or more heavy quarks for strange quarks.

We investigate the variation of statistical properties of the fissile nucleus, especially entropy, and nuclear level density, along different fission paths. The calculations were focused on comparing axial and triaxial trajectories leading to fission of ²⁹⁶Lv. We observe that change of shell effects and their suppression rates with deformation can substantially influence fission dynamics. Furthermore, the fission process exhibits iso-entropic behavior at high excitation energies, while pronounced entropy variations are observed at lower energies. We derive a deformation-dependent level density parameter that plays a critical role in estimating the survival probability of a superheavy nucleus. The competition between different fission paths was further studied by employing a master equation approach, thereby demonstrating the critical role of entropy and thermodynamic properties in shaping fission dynamics within multidimensional deformation spaces.

Understanding the strong interactions within baryonic systems beyond the up and down quark sector is pivotal for a comprehensive description of nuclear forces. This study explores the interactions involving hyperons, particularly the (varLambda ) particle, within the framework of nuclear lattice effective field theory (NLEFT). By incorporating (varLambda ) hyperons into the NLEFT framework, we extend our investigation into the (S = -1) sector, allowing us to probe the third dimension of the nuclear chart. We calculate the (varLambda ) separation energies ((B_{varLambda })) of hypernuclei up to the medium-mass region, providing valuable insights into hyperon–nucleon (YN) and hyperon–nucleon–nucleon (YNN) interactions. Our calculations employ high-fidelity chiral interactions at N( ^3)LO for nucleons and extend it to (varLambda ) hyperons with leading-order S-wave YN interactions as well as YNN forces constrained only by the (A=4,5) systems. Our results contribute to a deeper understanding of the SU(3) symmetry breaking and establish a foundation for future improvements in hypernuclear calculations.

The research on the (n, γ) cross section of selenium isotope ⁷⁴Se, determined using the activation method, has potential applications that could pique your interest. The irradiation was conducted by a Bremsstrahlung photon beam generated by an electron medical accelerator, yielding neutrons within an energy spectrum ranging from 1 keV to 1 MeV. The production of ⁷⁵Se nuclei occurs through a combination of neutron capture and photonuclear reactions in the field of a medical linear accelerator. Both the photon- and neutron-induced contributions had to be studied. Photo- and neutron-capture cross sections of ⁷⁴Se were calculated using the TALYS 2.0 nuclear reaction code and compared with our measurement. The results show that this method could be employed to study reactions relevant to nuclear astrophysics in medical centers, opening up new avenues for research and application.

Understanding the substructure of atomic nuclei, particularly the clustering of nucleons inside them, is essential for comprehending nuclear dynamics. Various cluster configurations can emerge depending on excitation energy, the number and types of core clusters, and the presence of excess neutrons. Despite the prevalence of tightly bound cluster formations in low-lying states, understanding the correlation between clusters and their formation mechanisms remains incomplete. This exploring study investigates nuclear clustering at the electron–ion collider (EIC) using simulations based on the modified BeAGLE model. By simulating collisions involving (e+^{9})Be, (e+^{12})C, and (e+^{16})O nuclei, we find that the average energy of particles (langle E rangle ) and the system size ratios of particles at forward rapidity exhibit sensitivity to alpha clustering and its various configurations. These findings offer valuable insights into the dynamics of nuclear clustering and its implications for future studies at the EIC.