Wed·Dec 7, 2016Wednesday·December 7, 2016

1. 01*

   Nuclear Reactions: Mechanism and Spectroscopy. Volume I

   Ron W Nielsen

   Volume I of two. This document could be of interest to anyone who wants to have a comprehensive inside information about the research in nuclear physics from its early beginnings to later years. It describes highlights of my research work from the late 1950s to the late 1980s. It presents a panorama of experimental and theoretical methods used in the study of nuclear reactions (their mechanism and their application to the study of nuclear structure), the panorama ranging from simple detection techniques used in the early research to more complicated in later years, from simple theoretical interpretations to more complicated descriptions. This document describes my research work in Poland, Australia, Switzerland and Germany using various particle accelerators and a wide range of experimental and theoretical techniques. It presents a typical cross section of experimental and theoretical work in the early and later stages of nuclear research in the field of nuclear reactions

   nucl-ex0 citations
2. 02*

   Nuclear Reactions: Mechanism and Spectroscopy. Volume II

   Ron W. Nielsen

   Volume II of two. This document could be of interest to anyone who wants to have a comprehensive inside information about the research in nuclear physics from its early beginnings to later years. It describes highlights of my research work from the late 1950s to the late 1980s. It presents a panorama of experimental and theoretical methods used in the study of nuclear reactions (their mechanism and their application to the study of nuclear structure), the panorama ranging from simple detection techniques used in the early research to more complicated in later years, from simple theoretical interpretations to more complicated descriptions. This document describes my research work in Poland, Australia, Switzerland and Germany using various particle accelerators and a wide range of experimental and theoretical techniques. It presents a typical cross section of experimental and theoretical work in the early and later stages of nuclear research in the field of nuclear reactions.

   nucl-ex0 citations
3. 03*

   Is a Trineutron Resonance Lower in Energy than a Tetraneutron Resonance?

   S. Gandolfi🇺🇸 · H.-W. Hammer🇩🇪 · P. Klos🇩🇪 · J. E. Lynn🇩🇪 · A. Schwenk🇩🇪

   We present quantum Monte Carlo calculations of few-neutron systems confined in external potentials based on local chiral interactions at next-to-next-to-leading order in chiral effective field theory. The energy and radial densities for these systems are calculated in different external Woods-Saxon potentials. We assume that their extrapolation to zero external-potential depth provides a quantitative estimate of three- and four-neutron resonances. The validity of this assumption is demonstrated by benchmarking with an exact diagonalization in the two-body case. We find that the extrapolated trineutron resonance, as well as the energy for shallow well depths, is lower than the tetraneutron resonance energy. This suggests that a three-neutron resonance exists below a four-neutron resonance in nature and is potentially measurable. To confirm that the relative ordering of three- and four-neutron resonances is not an artifact of the external confinement, we test that the odd-even staggering in the helium isotopic chain is reproduced within this approach. Finally, we discuss similarities between our results and ultracold Fermi gases.

   ↳ nucl-thnucl-exPRL(2017)·80 citations
4. 04*

   SQM2016: Theory Summary

   V. Greco🇮🇹

   This is an overview of the main theoretical developments presented at SQM2016 held in Berkeley, California (USA) in June 2015.

   ↳ nucl-thhep-phnucl-exJ.Phys.Conf.Ser.(2017)·3 citations
5. 05*

   Charged-particle detection efficiencies of close-packed CsI arrays

   P. Morfouace🇺🇸 · W. G. Lynch🇺🇸 · M. B. Tsang🇺🇸

   Detector efficiency determination is essential to correct the measured yields and extract reliable cross sections of particles emitted in nuclear reactions. We investigate the efficiencies for measuring the full energies of light charged particle in arrays of CsI crystals employed in particle detection arrays such as HiRA, LASSA and MUST2. We perform these simulations with a GEANT4 Monte Carlo transport code implemented in the NPTool framework. Both Coulomb multiple scattering and nuclear reactions within the crystal can significantly reduce the efficiency of detecting the full energy of high energy particles. The calculated efficiencies decrease exponentially as a function of the range of the particle and are quite similar for both the hydrogen ($p,d,t$) and helium (${}^3$He, $\alpha$) isotopes. The use of a close-packed array introduces significant position dependent efficiency losses at the interior boundaries between crystals that need to be considered in the design of an array and in the efficiency corrections of measured energy spectra.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2017)·9 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.