Nuclear Theory·nucl-th

Friday·November 22, 2024

3 papers—2 primary·1 cross-listed

01
Probing small neutron skin variations in isotope pairs by hyperon-antihyperon production in antiproton--nucleus interactions
Falk Schupp🇩🇪 · Josef Pochodzalla🇩🇪 · Michael Bölting🇩🇪 · Martin Christiansen🇩🇪 · Theodoros Gaitanos🇬🇷 · Horst Lenske🇩🇪 · Marcell Steinen🇩🇪
We propose a new method to study the evolution of the neutron periphery between different isotopes by considering antiproton--nucleus interactions close to the production threshold of $Λ Λ$ and $Σ^{-} Λ$ pairs. At low energies, $Λ Λ$ pairs are produced in $p + p$ collisions, while $Σ^{-} Λ$ pairs can only be produced in $p + n$ interactions. Within a simple geometrical picture we show that the double ratio for the production of $Σ^{-} Λ$ and $Λ Λ$ pairs for two different isotopes are related to the variation of the neutron skin thickness between the two nuclei. Performing high statistics calculations with the Gießen Boltzmann--Uehling--Uhlenbeck (GiBUU) transport model for several isotope pairs covering a wide range of elements we verify a strong correlation between the double ratio from the full transport simulations and the schematic model. This correlation enables us to quantify the potential of the proposed method for precise studies of neutron skin variations in isotope chains.
nucl-thnucl-exPRC(2025)·2 citations
02
Proton-neutron pair correlations in neutron-rich nuclei
Kenichi Yoshida
[Background] Nuclear pairing is a well-established many-body correlation, particularly among like particles in a spin-singlet state. However, the strength of spin-triplet proton-neutron (pn) pairing in nuclei has remained a long-standing and unresolved issue. [Purpose] The relative strength of spin-triplet pn pairing compared to spin-singlet one is investigated by introducing and analyzing the polarizability of the response to pn pair transfers. [Method] The nuclear energy-density functional method is employed. The ground state of the target nucleus is described using the Hartree-Fock-Bogoliubov approximation, which accounts for the conventional superfluidity of like-particle pairs. The response to pn pair transfers is then analyzed using the pn quasiparticle random-phase approximation. [Results] The spin-singlet pn-pair correlation is strongest at $N = Z$ and decreases monotonically with the increasing number of excess neutrons, whereas the spin-triplet pn-pair correlation is shown to depend non-monotonically on the neutron number and can be enhanced in cases where the pn-pair transfers involving the $π j_{>} \otimes ν j_{<}$ configuration occur at low energy. [Conclusions] The shell effect, which uniquely appears in spin-triplet pn-pair correlation, serves as a key indicator of the strength of pn-pair correlations.
nucl-thnucl-ex1 citation
03
Transverse spin effects and light-quark dipole moments at lepton colliders
Xin-Kai Wen🇨🇳 · Bin Yan🇨🇳 · Zhite Yu🇺🇸 · C.-P. Yuan🇺🇸
We propose to probe light-quark dipole interactions at lepton colliders using the azimuthal asymmetry of a collinear dihadron pair $(h_{1} h_{2})$ produced in association with another hadron $h^{'}$ . This asymmetry, arising from quantum interference in the quark spin space, is exclusively sensitive to dipole interactions at the leading power of the new physics scale and simultaneously probes both the real and imaginary components of the dipole couplings. By combining all possible channels of $h^{'}$ , this method allows for disentangling the up and down quark dipole moments and has the potential to significantly strengthen current constraints by one to two orders of magnitude.
↳ hep-phhep-exnucl-exnucl-thPRD(2025)·16 citations

Affiliations

first authorsco-authorsvia INSPIRE

Probing small neutron skin variations in isotope pairs by hyperon-antihyperon production in antiproton--nucleus interactions

Proton-neutron pair correlations in neutron-rich nuclei

Transverse spin effects and light-quark dipole moments at lepton colliders

Affiliations