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Nuclear Theory·nucl-th

Thursday·February 25, 2021

7 papers—4 primary·3 cross-listed

All7Primary4Cross-lists3
  1. 05

    [Submitted on 24 Feb 2021] (cross-list from nucl-ex)

    Spontaneous double alpha decay: First experimental limit and prospects of investigation

    V.I. Tretyak

    Nuclear decays with simultaneous emission of two alpha particles are energetically possible for a number of nuclides. Prospects of searching for such kind of decay for nuclides present in the natural isotopic composition of elements are discussed here. The first experimental limit on half-life for 2alpha decay is set for 209Bi as T1/2 > 2.9e20 y at 90% C.L., using the data of work [P. de Marcillac et al., Nature 422 (2003) 876]. Theoretical T1/2 estimations for the process are also given. Using these values, which are on the level of 1e33 y or more, one can conclude that the prospects of experimental observation of 2alpha decay are very pessimistic.

    Comments:
    8 p., version published in Nuclear Physics and Atomic Energy 22 (2021) 121 + small note is added that the idea on 2a decay appeared independently
    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2102.12005 [pdf]
    Nucl.Phys.Atom.Energy(2021)·19 citations
  2. 06

    [Submitted on 24 Feb 2021] (cross-list from nucl-ex)

    Production of high purity Mn from V targets with -beams at cyclotrons

    A. Colombi · M.P. Carante · F. Barbaro · L. Canton · A. Fontana

    Radioisotope Mn is of special interest for multimodal imaging. Using state-of-art nuclear reaction codes, we study the alternative nuclear reaction route V(,x)Mn in comparison with the standard production routes based upon the use of chromium targets. The integral yields of Mn and contaminants have been evaluated. The main outcome of this investigation is that the production of the main contaminant isotope Mn is expected to be lower than with Cr. The study also reveals a large spread in the cross-section data set and points out the need of more precise measurements of the reaction V(,x)Mn as well as the need of a more accurate theoretical description.

    Comments:
    Keywords: Cyclotron radionuclide production, Mn, Mn, Mn, multi-modal imaging,{\alpha}-induced reactions, nuclear reactions modeling
    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th); physics.med-ph (physics.med-ph)
    arXiv:
    2102.12228 [pdf]
    2 citations
  3. 07

    [Submitted on 24 Feb 2021] (cross-list from quant-ph)

    Imaginary Time Propagation on a Quantum Chip

    Francesco Turro🇮🇹 · Alessandro Roggero🇮🇹 · Valentina Amitrano🇮🇹 · Piero Luchi🇮🇹 · Kyle A. Wendt🇺🇸 · Jonathan L DuBois🇺🇸 · Sofia Quaglioni🇺🇸 · Francesco Pederiva🇮🇹

    Evolution in imaginary time is a prominent technique for finding the ground state of quantum many-body systems, and the heart of a number of numerical methods that have been used with great success in quantum chemistry, condensed matter and nuclear physics. We propose an algorithm to implement imaginary time propagation on a quantum computer. Our algorithm is devised in the context of an efficient encoding into an optimized gate, drawing on the underlying characteristics of the quantum device, of a unitary operation in an extended Hilbert space. However, we proved that for simple problems it can be successfully applied to standard digital quantum machines. This work paves the way for porting quantum many-body methods based on imaginary-time propagation to near-term quantum devices, enabling the future quantum simulation of the ground states of a broad class of microscopic systems.

    Comments:
    12 pages, 8 figures, 3 tables
    Subjects:
    Quantum Physics (quant-ph); Nuclear Theory (nucl-th)
    arXiv:
    2102.12260 [pdf]
    PRA(2022)·55 citations

Affiliations

first authorsco-authorsvia INSPIRE