Publications

Order by: publication date number of citations

• Study of the hyperon-nucleon interaction via final-state interactions in exclusive reactions

  Nicholas Zachariou, Daniel Watts, Yordanka Ilieva

  SciPost Phys. Proc. 3, 026 (2020) · published 25 February 2020 | Toggle abstract · pdf

  A novel approach that allows access to long-sought information on the Hyperon-Nucleon (YN) interaction was developed by producing a hyperon beam within a few-body nuclear system, and studying final-state interactions. The determination of polarisation observables, and specifically the beam spin asymmetry, in exclusive reactions allows a detailed study of the various final-state interactions and provides us with the tools needed to isolate kinematic regimes where the YN interaction dominates. High-statistics data collected using the CLAS detector housed in Hall-B of the Thomas Jefferson laboratory allows us to obtain a large set of polarisation observables and place stringent constraints on the underlying dynamics of the YN interaction.

• Exotic structures in exotic nuclei

  F. Miguel Marqués

  SciPost Phys. Proc. 3, 001 (2020) · published 24 February 2020 | Toggle abstract · pdf

  Nuclei with proton and neutron numbers away from stability are known as exotic, and provide stringent tests of nuclear models, mainly developed for the description of stable nuclei. However, only the most extreme combinations lead to literally exotic structures, with sometimes unexpected properties. In this contribution we review some selected examples around the neutron dripline of very light elements: neutron halo structures with embedded substructures in the boron chain; the emission of neutron pairs in $^{16}$Be; and the existence of multi-neutron resonances in `superheavy' hydrogen isotopes.

• Calculation of asymptotic normalization coefficients in the complex-ranged Gaussian basis

  Dinmukhamed A. Sailaubek, Olga A. Rubtsova

  SciPost Phys. Proc. 3, 043 (2020) · published 27 February 2020 | Toggle abstract · pdf

  A new technique towards finding asymptotic normalization coefficients in the complex-ranged Gaussian basis is presented. It is shown that a diagonalisation procedure for the total Hamiltonian matrix in the given basis results in approximation for a radial part of the bound state wave function from the origin up to the far asymptotic distances, which allows to extract ANCs rather accurately. The method is illustrated by calculations of single-particle ANCs for nuclei bound states in cases of non-local nucleon-nucleus interactions, in particular, phenomenological global potentials with the Perey-Buck's non-locality.

• Determination of phase space region for cross-check validation of the neutron detection in the BINA experiments

  B. Włoch, K. Bodek, I. Ciepał, M. Eslami-Kalantari, J. Golak, N. Kalantar-Nayestanaki, G. Khatri, St. Kistryn, B. Kłos, A. Kozela, J. Kuboś, P. Kulessa, A. Łobejko, A. Magiera, H. Mardanpour, J. Messchendorp, I. Mazumdar, W. Parol, A. Ramazani-Moghaddam-Arani, D. Rozpędzik, R. Skibiński, I. Skwira-Chalot, E. Stephan, A. Wilczek, H. Witała, A Wrońska, J. Zejma

  SciPost Phys. Proc. 3, 006 (2020) · published 24 February 2020 | Toggle abstract · pdf

  Deuteron breakup reactions are basic laboratories for testing nuclear force models. Recent improvements in the data analysis allow for direct identification of neutrons in the BINA detection setup. This opens up the opportunity to study new aspects of few-nucleon system dynamics like charge dependence of nuclear force or Coulomb interaction. In this paper we determine regions along the kinematical curves where differential cross section of deuteron-proton breakup reactions can be measured by the proton-neutron and proton-proton coincidences simultaneously. This is particularly useful for validation of the neutron detection technique.

• Influence of the Pauli principle on two-cluster potential energy

  Yuliya A. Lashko, Victor S. Vasilevsky, Gennady F. Filippov

  SciPost Phys. Proc. 3, 021 (2020) · published 25 February 2020 | Toggle abstract · pdf

  We study effects of the Pauli principle on the potential energy of two-cluster systems. The object of the investigation is the lightest nuclei of p-shell with a dominant $\alpha$-cluster channel. For this aim we construct matrix elements of two-cluster potential energy between cluster oscillator functions with and without full antisymmetrization. Eigenvalues and eigenfunctions of the potential energy matrix are studied in detail. Eigenfunctions of the potential energy operator are presented in oscillator, coordinate and momentum spaces. We demonstrate that the Pauli principle affects more strongly the eigenfunctions than the eigenvalues of the matrix and leads to the formation of resonance and trapped states.

• Lattice phase shifts and mixing angles for an arbitrary number of coupled channels

  Lukas Bovermann, Evgeny Epelbaum, Hermann Krebs, Dean Lee

  SciPost Phys. Proc. 3, 052 (2020) · published 27 February 2020 | Toggle abstract · pdf

  We present a lattice method for determining scattering phase shifts and mixing angles for the case of an arbitrary number of coupled channels. The proposed method combines a spherical wall boundary condition and a channel-mixing auxiliary potential to extract the full-rank S-matrix from the radial wave functions. We consider the scattering problem of two spin-1 bosons interacting with a test potential involving up to four coupled channels. For this benchmark system, the phase shifts and mixing angles are shown to agree on the lattice and in the continuum. Our method should allow to extend previous two-channel nuclear lattice EFT simulations to mixing of more than two partial waves.

• Study of light nuclei by polarization observables in electron scattering

  Simon Širca

  SciPost Phys. Proc. 3, 048 (2020) · published 27 February 2020 | Toggle abstract · pdf

  Electron-induced proton, neutron and deuteron knock-out remains the most versatile probe of the electro-magnetic properties and spin structure of light nuclei. The advent of highly polarized beams and targets and improvements in recoil polarization methods, as well as analysis and simulation techniques, have enabled us to study the static and dynamical properties of few-body systems with unprecedented precision. Recent experiments at Jefferson Lab and MAMI are presented and put into perspective of state-of-the art Faddeev calculations, with focus on the $^\mathbf{3}\mathbf{He}$ nucleus.