arXiv subjects

S. Amangeldinova

Publications and source records attributed to S. Amangeldinova.

5 recordsLinked to original sources

arXiv2026

Constraints on Neutron-Electron Quantum Dark Forces

Interactions induced by dark matter particles which couple bilinearly to standard model particles through quantum fluctuations were termed quantum dark forces by Brax, Fichet, and Pignol, who constrained the mass and couplings of dark scalar, dark vector, and dark fermion bilinear exchange between nucleons. We extend their results to derive new constraints on quantum dark forces from bilinear scalar exchange between neutrons and electrons

hep-ph↗

arXiv2026

On three-cluster resonance structure of hypernuclei $_Λ^{7}$He, $_Λ^{7}$Li and $_Λ^{7}$Be

The bound and resonance states of hypernuclei $_Λ^{7}$He, $_Λ^{7}$Li and $_Λ^{7}$Be are studied within a three-cluster model. Within this model, hypernuclei $_Λ^{7}$He, $_Λ^{7}$Li and $_{Λ}^{7}$Be are considered as three-cluster systems $^{4}$He+$^2n$+$Λ$, $^{4}$He+$d$+$Λ$, $^{4}$He+$^2p$+$Λ$, respectively. Special attention is paid to determining resonance states in the three-cluster continuum of these hypernuclei and to study their nature. One semi-realistic nucleon-nucleon potential is employed to determine the internal structure of the clusters $^{4}$He, $^2n$, $d$ and $^2p$, and their interaction. Three versions of the nucleon-hyperon potential, known as the YNG potential, are employed to determine the interaction of the listed clusters with the lambda hyperon. A set of very narrow and fairly wide resonance states is found in the three-cluster continuum of $_Λ^{7}$He, $_Λ^{7}$Li and $_Λ^{7}$Be. The narrowest resonance states were detected in $_Λ^{7}$He and $_Λ^{7}$Li and their total width does not exceed 10 keV. The dominant decay channels of these resonance states are revealed.

nucl-th↗

arXiv2025

Discrete and continuous spectrum of lightest hypernuclei

We analyze the peculiarities of the interaction of the lambda hyperon with s-shell nuclei. The spectra of bound and scattering states are studied in the hypernuclei $_Λ^{2}$H, $_Λ^{3}$H, $_Λ^{4}$H, $_Λ^{4}$He and $_Λ^{5}$He, which is considered as two-cluster configurations $p+Λ$, $d$+$Λ$, $^{3}$H+$Λ$, $^{3}$He+$Λ$, $^{4}$He+$Λ$, respectively. The explicit form of the folding potentials of such an interaction is presented in coordinate and oscillator representations, which help us to understand the structure of hypernuclei of interest. We compare energies of bound states, phase shifts of the elastic lambda hyperon, and neutron scattering from s-shell nuclei.

nucl-th↗

arXiv2025

Using the Neutron Fizeau Effect and Neutron Interferometry to Measure Energy-Dependent Contributions to the Neutron Optical Potential

We propose a method to measure the energy dependence of the neutron optical potential $dV_{opt}/dE$ in the slow neutron energy regime. Our method makes essential use of a special property of the phase shift for a nonrelativistic neutron in moving matter, known as the neutron Fizeau effect. If a neutron traverses a medium which moves along the surfaces of its own parallel boundaries, the neutron only experiences a phase shift if the neutron optical potential of matter depends on the incident neutron energy. This feature of the neutron Fizeau effect can be combined with newly-developed forms of neutron interferometry to conduct sensitive measurements of $dV_{opt}/dE$. We describe some examples of scientific applications of this idea in the fields of neutron optics, subthreshold neutron-nucleus resonances, parity violation in low-energy p-wave neutron-nucleus resonances, and neutron scattering amplitudes of the nuclei of rare earth elements.

nucl-ex↗

arXiv2025

Structure of hypernucleus $_Λ^{7}$Li within microscopic three-cluster model

The structure of bound and resonance states of the hypernucleus $_Λ^{7}$Li is studied within a three-cluster model. This nucleus is considered a three-cluster structure consisting of $^{4}$He, a deuteron, and a lambda hyperon. The chosen three-cluster configuration allows us to describe more accurately the structure of hypernucleus $_Λ^{7}$Li and the dynamics of different processes that involve interactions of lightest nuclei and hypernuclei. The main goal of the present investigations is to find resonance states in the three-cluster continuum of $_Λ^{7}$Li and determine their nature. A set of narrow resonance states is detected at the energy range 0$<E\leq$2 MeV above the three-cluster threshold $^{4}$He+$d$+$Λ$.

nucl-th↗