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Nuclear Theory·nucl-th

Tuesday·April 11, 2023

15 papers—8 primary·7 cross-listed

All15Primary8Cross-lists7
  1. 09

    [Submitted on 7 Apr 2023] (cross-list from hep-ph)

    Prospects for GPDs extraction with Double DVCS

    K. Deja🇵🇱 · V. Martinez-Fernandez🇵🇱 · B. Pire🇵🇱 · P. Sznajder🇵🇱 · J. Wagner🇫🇷

    Double deeply virtual Compton scattering (DDVCS) is the process where an electron scatters off a nucleon and produces a lepton pair. The main advantage of this process in contrast with deeply virtual and timelike Compton scatterings (DVCS and TCS) is the possibility of directly measuring GPDs for at leading order in (LO). We present a new calculation of the DDVCS amplitude based on the methods developed by R. Kleiss and W. J. Stirling in the 1980s. These techniques produce expressions for amplitudes that are perfectly suited for implementation in numerical simulations. Via the PARTONS software, the correctness of this new formulation has been tested by comparing the DVCS and TCS limits of DDVCS with independent calculations of DVCS and TCS.

    Comments:
    5 pages, 4 figures, proceedings for the XXIX Cracow Epiphany Conference
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2304.03704 [pdf]
    Acta Phys.Polon.Supp.(2023)·5 citations
  2. 10

    [Submitted on 7 Apr 2023] (cross-list from hep-ph)

    Light-front puzzles

    Wayne Polyzou🇺🇸

    Light-front formulations of quantum field theories have many advantages for computing electroweak matrix elements of strongly interacting systems and other quantities that are used to study hadronic structure. The theory can be formulated in Hamiltonian form so non-perturbative calculations of the strongly interacting initial and final states are in principle reduced to linear algebra. These states are needed for calculating parton distribution functions and other types of distribution amplitudes that are used to understand the structure of hadrons. Light-front boosts are kinematic transformations so the strongly interacting states can be computed in any frame. This is useful for computing current matrix elements involving electroweak probes where the initial and final hadronic states are in different frames related by the momentum transferred by the probe. Finally in many calculations the vacuum is trivial so the calculations can be formulated in Fock space. The advantages of light front-field theory would not be interesting if the light-front formulation was not equivalent to the covariant or canonical formulations of quantum field theory. Many of the distinguishing properties of light-front quantum field theory are difficult to reconcile with canonical or covariant formulations of quantum field theory. This paper discusses the resolution of some of the apparent inconsistencies in canonical, covariant and light-front formulations of quantum field theory. The puzzles that will be discussed are (1) the problem of inequivalent representations (2) the problem of the trivial vacuum (3) the problem of ill-posed initial value problems (4) the problem of rotational covariance (5) the problem of zero modes and (6) the problem of spontaneously broken symmetries.

    Comments:
    29 pages, no figures - corrected reference 35
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    2304.03847 [pdf]
    J.Phys.A(2024)·4 citations
  3. 11

    [Submitted on 9 Apr 2023] (cross-list from quant-ph)

    Entanglement Structures in Quantum Field Theories II: Distortions of Vacuum Correlations Through the Lens of Local Observers

    Natalie Klco🇺🇸 · D. H. Beck🇺🇸

    When observing a quantum field via detectors with access to only the mixed states of spatially separated, local regions -- a ubiquitous experimental design -- the capacity to access the full extent of distributed entanglement can be limited, shrouded by classical correlations. By performing projective measurements of the field external to two detection patches and classically communicating the results, underlying pure states may be identified for which entanglement quantification is clear. In the Gaussian continuous-variable states of the free scalar field vacuum, this protocol uncovers a disparity between the spacelike entanglement established within the field and that which is locally detectable. This discrepancy is found to grow exponentially with the separation between observation regions. The protocol developed herein offers insight and practical guidance for clarifying the unavoidable distortion of quantum field correlations when viewed from the vantage of a pair of local observers.

    Comments:
    13 pages, 3 figures, 5 appendices
    Subjects:
    Quantum Physics (quant-ph); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2304.04143 [pdf]
    PRA(2023)·13 citations
  4. 12

    [Submitted on 9 Apr 2023] (cross-list from quant-ph)

    Quantum Mechanics Lecture Notes. Selected Chapters

    Shimon Levit

    These are extended lecture notes of the quantum mechanics course which I am teaching in the Weizmann Institute of Science graduate physics program. They cover the topics listed below. The first four chapter are posted here. Their content is detailed on the next page. The other chapters are planned to be added in the coming months. 1. Motion in External Electromagnetic Field. Gauge Fields in Quantum Mechanics. 2. Quantum Mechanics of Electromagnetic Field 3. Photon-Matter Interactions 4. Quantization of the Schrödinger Field (The Second Quantization) 5. Open Systems. Density Matrix 6. Adiabatic Theory. The Berry Phase. The Born-Oppenheimer Approximation 7. Mean Field Approaches for Many Body Systems -- Fermions and Bosons

    Subjects:
    Quantum Physics (quant-ph); cond-mat.other (cond-mat.other); Quantum Gases (cond-mat.quant-gas); Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
    arXiv:
    2304.04247 [pdf]
    0 citations
  5. 13

    [Submitted on 10 Apr 2023] (cross-list from hep-ph)

    Rotation and vibration in tetraquarks

    Amir Jalili🇵🇱 · Jorge Segovia🇪🇸 · Feng Pan🇨🇳 · Yan-An Luo🇨🇳

    A novel approach is introduced for obtaining precise solutions of the pairing Hamiltonian for tetraquarks, which utilizes an algebraic technique in infinite dimensions. The parameters involved in the transition phase are calibrated based on potential tetraquark candidates derived from phenomenology. Our investigation shows that the rotation and vibration transitional theory delivers a more accurate explanation for heavy tetraquarks compared to other methods utilizing the same formalism. To illustrate the concept, we compute the spectra of several tetraquarks, namely charm, bottom, bottom-charm and open charm and bottom systems, and contrast them with those of other particles.

    Comments:
    13 pages, 4 figures, 4 Tables. Invited contribution to a Special Issue of Few Body Systems: "Emergence and Structure of Baryons -- Selected Contributions from the International Conference Baryons 2022"
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2304.04404 [pdf]
    Few Body Syst.(2023)·3 citations
  6. 14

    [Submitted on 10 Apr 2023] (cross-list from hep-ph)

    Variation of the quadrupole hyperfine structure and nuclear radius due to an interaction with scalar and axion dark matter

    V. V. Flambaum🇦🇺 · A. J. Mansour🇦🇺

    Atomic spectroscopy is used to search for the space-time variation of fundamental constants which may be due to an interaction with scalar and pseudo-scalar (axion) dark matter. In this letter, we study the effects which are produced by the variation of the nuclear radius and electric quadrupole moment. The sensitivity of the electric quadrupole hyperfine structure to both the variation of the quark mass and the effects of dark matter exceeds that of the magnetic hyperfine structure by 1-2 orders of magnitude. Therefore, the measurement of the variation of the ratio of the electric quadrupole and magnetic dipole hyperfine constants is proposed. The sensitivity of the optical clock transitions in the Yb ion to the variation of the nuclear radius allows us to extract, from experimental data, limits on the variation of the hadron and quark masses, the QCD parameter and the interaction with axion and scalar dark matter.

    Comments:
    v2: References added
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
    arXiv:
    2304.04469 [pdf]
    PRL(2023)·10 citations
  7. 15

    [Submitted on 10 Apr 2023] (cross-list from hep-ph)

    Leptogenesis and Dark Matter-Nucleon Scattering Cross Section in the SE6SSM

    Roman Nevzorov🇷🇺

    The E6 inspired extension of the minimal supersymmetric (SUSY) standard model (MSSM) with an extra U(1)_N gauge symmetry, under which right-handed neutrinos have zero charge, involves exotic matter beyond the MSSM to ensure anomaly cancellation. We consider the variant of this extension (SE6SSM) in which the cold dark matter is composed of the lightest neutral exotic fermion and gravitino. The observed baryon asymmetry can be induced in this case via the decays of the lightest right-handed neutrino/sneutrino into exotic states even for relatively low reheating temperatures T_R < 10^{6-7} GeV. We argue that there are some regions of the SE6SSM parameter space, which are safe from all current constraints, and discuss the implications of this model for collider phenomenology.

    Comments:
    30 pages, 3 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics — Lattice (hep-lat); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    2304.04629 [pdf]
    Universe(2023)·6 citations

Affiliations

first authorsco-authorsvia INSPIRE