Publications

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• Clustering in $^{18}$O - absolute determination of branching ratios via high-resolution particle spectroscopy

  S. Pirrie, C. Wheldon, Tz. Kokalova, J. Bishop, R. Hertenberger, H.-F. Wirth, S.~Bailey, N. Curtis, D. Dell'Aquila, Th. Faestermann, D. Mengoni, R. Smith, D.Torresi, A. Turner

  SciPost Phys. Proc. 3, 009 (2020) · published 24 February 2020 | Toggle abstract · pdf

  The determination of absolute branching ratios for high-energy states in light nuclei is an important and useful tool for probing the underlying nuclear structure of individual resonances: for example, in establishing the tendency of an excited state towards $\alpha$-cluster structure. Difficulty arises in measuring these branching ratios due to similarities in available decay channels, such as ($^{18}$O,$n$) and ($^{18}$O,$2n$), as well as differences in geometric efficiencies due to population of bound excited levels in daughter nuclei. Methods are presented using Monte Carlo techniques to overcome these issues.

  3 citations

• Low-energy neutron scattering on light nuclei and $^{19}$B as a $^{17}$B-$n$-$n$ three-body system in the unitary limit

  Jaume Carbonell, Emiko Hiyama, Rimantas Lazauskas, F. Miguel Marqués

  SciPost Phys. Proc. 3, 008 (2020) · published 24 February 2020 | Toggle abstract · pdf

  We consider the evolution of the neutron-nucleus scattering length for the lightest nuclei. We show that, when increasing the number of neutrons in the target nucleus, the strong Pauli repulsion is weakened and the balance with the attractive nucleon-nucleon interaction results into a resonant virtual state in $^{18}$B. We describe $^{19}$B in terms of a $^{17}$B-$n$-$n$ three-body system where the two-body subsystems $^{17}$B-$n$ and $n$-$n$ are unbound (virtual) states close to the unitary limit. The energy of $^{19}$B ground state is well reproduced and two low-lying resonances are predicted. Their eventual link with the Efimov physics is discussed. This model can be extended to describe the recently discovered resonant states in $^{20,21}$B.

• Impact of uncertainties of unbound 10Li on the ground state of two-neutron halo 11Li

  Jagjit Singh, Wataru Horiuchi

  SciPost Phys. Proc. 3, 007 (2020) · published 24 February 2020 | Toggle abstract · pdf

  Recently, the energy spectrum of 10Li was measured upto 4.6 MeV, via one-neutron transfer reaction d(9Li, p)10Li. Considering the ambiguities on the 10Li continuum spectrum with reference to new data, we report the con guration mixing in the ground state of the two-neutron halo nucleus 11Li for two different choices of the 9Li+n potential. For the present study, we employ a three-body (core+n+n) structure model developed for describing the two-neutron halo system by explicit coupling of unbound continuum states of the subsystem (core+n), and discuss the two-neutron correlations in the ground state of 11Li.

• 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.

• Current stage of studies of the star configurations at intermediate energies with the use of the BINA detector

  A. Wilczek, A. Szadzinski, K. Bodek, I. Ciepal, M. Eslami-Kalantari, N. Kalantar-Nayestanaki, G. Khatri, St. Kistryn, B. Klos, A. Kozela, J. Kubos, P. Kulessa, A. Lobejko, A. Magiera, H. Mardanpour, J. Messchendorp, I. Mazumdar, W. Parol, A. Ramazani-Moghaddam-Aran, R. Ramazani-Sharifabadi, D. Rozpedzik, I. Skwira-Chalot, E. Stephan, B. Wloch, A. Wronska, J. Zejma

  SciPost Phys. Proc. 3, 005 (2020) · published 24 February 2020 | Toggle abstract · pdf

  The Space Star Anomaly in proton-deuteron breakup cross-section occurs at energies of about 10 MeV. Data for higher energies are sparse. Therefore, a systematic scan over star configurations in the range of intermediate energies between 50 and 100 MeV/nucleon is carried out on the basis of data collected with the large acceptance BINA detector. The preliminary cross section results for forward star configurations at 80 MeV/nucleon slightly surpass the theoretical calculations, but the systematic uncertainties are still under study. Also, a new variable describing rotation of star configurations is proposed.

• Measurement of spin correlation coefficients p-$^{3}$He scattering at 65 MeV

  M. Inoue, K. Sekiguchi, K. Miki, A. Watanabe, S. Nakai, S. Shibuya, D. Sakai, Y. Utsuki, H. Umetsu, K. Hatanaka, H. Kanda, H. J. Ong, T. Wakasa, S. Goto, S. Mitsumoto, D. Inomoto, H. Kasahara, T. Ino, H. Sakai, Y. Maeda, K. Nonaka, T. Wakui, M. Itoh

  SciPost Phys. Proc. 3, 004 (2020) · published 24 February 2020 | Toggle abstract · pdf

  We performed the experiment of p–$^{3}$He scattering at 65 MeV by using polarized proton beams and the newly constructed polarized $^{3}$He target. The proton analyzing power $A_{y}$, the 3He analyzing power $A^{T}_{y}$, and the spin correlation coefficient $C_{yy}$ were measured. In the conference, the experimental data were compared with the rigorous numerical calculations based on various nuclear potentials. Large discrepancies between the experimental data and the calculations were found in the $A^{T}_{y}$ and the $C_{yy}$ at the backward angles.

  1 citation

• Derivation of relativistic Yakubovsky equations under Poincaré invariance

  Hiroyuki Kamada

  SciPost Phys. Proc. 3, 003 (2020) · published 24 February 2020 | Toggle abstract · pdf

  Relativistic Faddeev-Yakubovsky four-nucleon scattering equations are derived including a 3-body force. We present these equations in the momentum space representation. The quadratic integral equations using the iteration method, in order to obtain boosted potentials and 3-body force, are demonstrated.

• Investigations of the few-nucleon systems within the LENPIC project

  Jacek Golak, Evgeny Epelbaum, Alessandro Grassi, Hiroyuki Kamada, Hermann Krebs, Patrick Reinert, Roman Skibiński, Volodymyr Soloviov, Kacper Topolnicki, Vitalii Urbanevych, Yuriy Volkotrub, Henryk Witała

  SciPost Phys. Proc. 3, 002 (2020) · published 24 February 2020 | Toggle abstract · pdf

  Results presented in this contribution are obtained within the Low Energy Nuclear Physics International Collaboration (LENPIC). LENPIC aims to develop chiral nucleon-nucleon and many-nucleon interactions complete through at least the fourth order in the chiral expansion. These interactions will be used together with consistently derived current operators to solve the structure and reactions of light and medium-mass nuclei including electroweak processes. In this contribution the current status of the chiral nuclear forces and current operators will be briefly discussed. A special role played by the calculations of nucleon-deuteron scattering will be explained.

  1 citation

• 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.

• Strangeness neutrality and QCD thermodynamics

  Wei-jie Fu, Jan M. Pawlowski, Fabian Rennecke

  SciPost Phys. Core 2, 002 (2020) · published 20 February 2020 | Toggle abstract · pdf

  Since the incident nuclei in heavy-ion collisions do not carry strangeness, the global net strangeness of the detected hadrons has to vanish. We investigate the impact of strangeness neutrality on the phase structure and thermodynamics of QCD at finite baryon and strangeness chemical potential. To this end, we study the low-energy sector of QCD within a Polyakov loop enhanced quark-meson effective theory with 2+1 dynamical quark flavors. Non-perturbative quantum, thermal, and density fluctuations are taken into account with the functional renormalization group. We show that the impact of strangeness neutrality on thermodynamic quantities such as the equation of state is sizable.

  23 citations