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Nuclear Theory·nucl-th

Tuesday·February 12, 2019

11 papers—7 primary·4 cross-listed

All11Primary7Cross-lists4
  1. 08

    [Submitted on 7 Feb 2019] (cross-list from quant-ph)

    Relation between exponential behavior and energy denominators -- Weak Coupling Limit

    Levering Wolfe🇺🇸 · Larry Zamick🇺🇸

    We show some interesting properties of tridiagonal and pentadiagonal matrices in the weak coupling limits. In the former case of this limit the ground state wave function amplitudes are identical to the Taylor expansion coefficients of the exponential function e. With regards to transition rates a dip in the pentadiagonal case which is not present in the tridiagonal case is explained. An intimate connection between energy denominators and exponential behavior is demonstrated.

    Comments:
    4 figures
    Subjects:
    Quantum Physics (quant-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1902.03119 [pdf]
    IJMPE(2019)·4 citations
  2. 09

    [Submitted on 10 Feb 2019] (cross-list from hep-ph)

    Coherence length of neutrino oscillations in quantum field-theoretical approach

    Vadim O. Egorov🇷🇺 · Igor P. Volobuev🇷🇺

    We consider a novel quantum field-theoretical approach to the description of processes passing at finite space-time intervals based on the Feynman diagram technique in the coordinate representation. The most known processes of this type are neutrino and neutral kaon oscillations. The experimental setting of these processes requires one to adjust the rules of passing to the momentum representation in the Feynman diagram technique in accordance with it, which leads to a modification of the Feynman propagator in the momentum representation. The approach does not make use of wave packets, both initial and final particle states are described by plane waves, which simplifies the calculations considerably. We consider neutrino oscillation processes, where the neutrinos are produced in three-particle weak decays of nuclei and detected in the charged-current interaction with nuclei or in the charged- and neutral-current interactions with electrons. Particular examples are considered and it is shown that the momentum spread of the produced neutrinos and the energy dependence of the differential cross section of the detection process result in the suppression of neutrino oscillation, which is characterized by a coherence length specific for a pair of production and detection processes. This coherence length turns out to be much less than the coherence length in the standard quantum-mechanical approach defined by the quantum uncertainty of neutrino momentum.

    Comments:
    LaTex, 18 pages, 15 figures. Multiple adjustments
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1902.03602 [pdf]
    PRD(2019)·18 citations
  3. 10

    [Submitted on 10 Feb 2019] (cross-list from hep-ph)

    Longitudinal spin asymmetries in polarized deuteron DIS with spectator tagging

    W. Cosyn🇧🇪 · C. Weiss🇺🇸

    Polarized electron-deuteron DIS with spectator proton tagging offers a way of measuring the neutron spin structure functions with maximal theoretical control of nuclear effects. We calculate the nuclear structure factors in the longitudinal double-spin asymmetries using methods of light-front nuclear structure. A unique feature of the spin-1 system is that spin asymmetries can be formed either relative to the cross section in all three spin states () or in the two maximum-spin states only (, involving tensor polarization). We find that the two-state deuteron spin asymmetry at small spectator proton momenta permits accurate extraction of the neutron structure function . Such measurements could be performed at a future electron-ion collider (EIC) with polarized deuteron beams and suitable forward detectors.

    Comments:
    7 pages, 2 figures; Proceedings of 23rd International Spin Physics Symposium (SPIN2018), 10-14 September, 2018; Ferrara, Italy
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1902.03678 [pdf]
    PoS(2019)·0 citations
  4. 11

    [Submitted on 10 Feb 2019] (cross-list from hep-ph)

    Deuteron helicity flip generalized parton distributions in a convolution model

    W. Cosyn🇧🇪 · B. Pire🇫🇷

    We discuss the general properties of generalized parton distributions with helicity flip (transversity) for spin-1 hadrons in the leading twist case. Using a basic light cone convolution model, we show the deuteron helicity amplitudes containing quark helicity flip GPDs and comment on the role deuteron angular momentum plays in these.

    Comments:
    4 pages, 2 figures; Proceedings of 8th International Conference on Quarks and Nuclear Physics (QNP2018) 13-17 Nov 2018; Tsukuba, Japan
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1902.03681 [pdf]
    JPS Conf.Proc.(2019)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE