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Nuclear Theory·nucl-th

Thursday·September 23, 2021

7 papers—1 primary·6 cross-listed

All7Primary1Cross-lists6
  1. 02

    [Submitted on 21 Sept 2021] (cross-list from hep-ph)

    Hunting for tetraquarks in ultra-pheripheral heavy ion collisions

    Angelo Esposito🇨🇭 · Claudio Andrea Manzari🇨🇭 · Alessandro Pilloni🇮🇹 · Antonio Davide Polosa🇮🇹

    Ultra-peripheral heavy ion collisions constitute an ideal setup to look for exotic hadrons because of their low event multiplicity and the possibility of an efficient background rejection. We propose to look for four-quark states produced by photon-photon fusion in these collisions at center-of-mass energy per nucleon pair . In particular, we focus on those states that would represent a definite smoking gun for the compact tetraquark model. We show that the , a likely compact state, is a perfect candidate for this search, and estimate a production cross section ranging from around nb to nb, depending on its quantum numbers. Furthermore, we discuss the importance of ultra-peripheral collisions to the search for the scalar and tensor partners of the predicted by the diquarkonium model, and not yet observed. The completion of such a flavor-spin multiplet would strongly speak in favor of the compact tetraquark model.

    Comments:
    6 pages, 2 figures, 3 tables; journal version
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
    arXiv:
    2109.10359 [pdf]
    PRD(2021)·33 citations
  2. 03

    [Submitted on 21 Sept 2021] (cross-list from hep-ph)

    The role of the chiral anomaly in polarized deeply inelastic scattering II: Topological screening and transitions from emergent axion-like dynamics

    Andrey Tarasov🇺🇸 · Raju Venugopalan🇺🇸

    In [1], we demonstrated that the structure function measured in polarized deeply inelastic scattering (DIS) is dominated by the triangle anomaly in both the Bjorken limit of large and the Regge limit of small . In the worldline formulation of quantum field theory, the triangle anomaly arises from the imaginary part of the worldline effective action. We show explicitly how a Wess-Zumino-Witten term coupling the topological charge density to a primordial isosinglet arises in this framework. We demonstrate the fundamental role played by this contribution both in topological mass generation of the and in the cancellation of the off-forward pole arising from the triangle anomaly in the proton's helicity . We recover the striking result by Shore and Veneziano that , where is the slope of the QCD topological susceptibility in the forward limit. We construct an axion-like effective action for at small that describes the interplay between gluon saturation and the topology of the QCD vacuum. In particular, we outline the role of "over-the-barrier" sphaleron-like transitions in spin diffusion at small . Such topological transitions can be measured in polarized DIS at a future Electron-Ion Collider.

    Comments:
    38 pages, 12 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    2109.10370 [pdf]
    PRD(2022)·48 citations
  3. 04

    [Submitted on 21 Sept 2021] (cross-list from hep-ph)

    Higher-Order Kinematical Effects in Deeply Virtual Compton Scattering

    Yuxun Guo🇺🇸 · Xiangdong Ji🇺🇸 · Kyle Shiells🇺🇸

    We study the deeply virtual Compton scattering cross-section in twist-two generalized parton distribution (GPD) approximation, and show that different choices of light-cone vectors and gauges for the final photon polarization will lead to different higher-order kinematical corrections to the cross-section formula. The choice of light-cone vectors affects kinematic corrections at the twist-three level, accounting for the differences between the cross-section formulas in the literature. On the other hand, kinematical corrections from higher-twist GPDs should eliminate the light-cone dependence at twist three. Those light-cone dependencies are studied systematically at JLab 12 GeV and future EIC kinematics. They serve as the intrinsic systematic uncertainties in extracting the Compton form factors through the cross-section formula. More importantly, they are also necessary for understanding cross-section measurements with higher-twist precision and to reconstruct higher-order Compton form factors.

    Comments:
    49 pages, 14 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2109.10373 [pdf]
    JHEP(2021)·26 citations
  4. 05

    [Submitted on 22 Sept 2021] (cross-list from physics.atom-ph)

    Nuclear charge radii of Na isotopes: A tale of two theories

    B. Ohayon · R.F. Garcia Ruiz · Z. H. Sun · G. Hagen · T. Papenbrock · B. K. Sahoo

    The accuracy of atomic theory calculations limits the extraction of nuclear charge radii from isotope shift measurements of odd-proton nuclei. For Na isotopes, though precise spectroscopic measurements have existed since more than half a century, calculations by different methods offer a wide range of values. Here, we present accurate atomic calculations to reliably extract the Na charge radii. By combining experimental matter radii with nuclear coupled-cluster calculations based on nucleon-nucleon and three-nucleon forces, we constrain the parameters obtained from the atomic calculations. Therefore, this study guides atomic theory and highlights the importance of using accurate atomic and nuclear computations in our understanding of the size of light nuclei.

    Subjects:
    Atomic Physics (physics.atom-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2109.10539 [pdf]
    PRC(2022)·26 citations
  5. 06

    [Submitted on 22 Sept 2021] (cross-list from nucl-ex)

    Mass measurements of 99-101In challenge ab initio nuclear theory of the nuclide 100Sn

    M. Mougeot🇩🇪 · D. Atanasov🇨🇭 · J. Karthein🇩🇪 · R. N. Wolf🇦🇺 · P. Ascher🇫🇷 · K. Blaum🇩🇪 · K. Chrysalidis🇨🇭 · G. Hagen🇺🇸 · J.D. Holt🇨🇦 · W.J. Huang🇩🇪 · G.R. Jasen🇺🇸 · I. Kulikov🇩🇪 and 14 other authors

    100Sn is of singular interest for nuclear structure. Its closed-shell proton and neutron configuration exhibit exceptional binding and 100Sn is the heaviest nucleus comprising protons and neutrons in equal number, a feature that enhances the contribution of the short-range, proton-neutron pairing interaction and strongly influences its decay via the weak interaction. Decays studies in the region of 100Sn have attempted to prove its doubly magic character but few have studied it from the ab initio theoretical perspective and none have addressed the odd-proton nuclear forces. Here we present, the first direct measurement of the exotic odd-proton nuclide 100In - the beta-decay daughter of 100Sn - and 99In, only one proton below 100Sn. The most advanced mass spectrometry techniques were used to measure 99In, produced at a rate of only a few ions per second, and to resolve the ground and isomeric states in 101In. The experimental results are confronted with new ab initio many-body approaches. The 100-fold improvement in precision of the 100In mass value exarcebates a striking discrepancy in the atomic mass values of 100Sn deduced from recent beta-decay results.

    Comments:
    12 pages, 4 figures, 1 Table
    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2109.10673 [pdf]
    Nat.Phys.(2021)·60 citations
  6. 07

    [Submitted on 22 Sept 2021] (cross-list from hep-ph)

    Chiral theory of -meson gravitational form factors

    E. Epelbaum🇩🇪 · J. Gegelia🇩🇪 · U.-G. Meißner🇩🇪 · M. V. Polyakov🇩🇪

    The low-energy chiral effective field theory of vector mesons and Goldstone bosons in external gravitational field is considered. The energy-momentum tensor is obtained and the gravitational form factors of the -meson are calculated up to next-to-leading order in the chiral expansion. This amounts to considering tree-level and one-loop order diagrams. The chiral expansion of the form factors at zero momentum transfer as well as of the slope parameters is worked out. Also, the long-range behaviour of the energy and internal force distributions is obtained and analysed.

    Comments:
    11 pages, 1 figure
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    2109.10826 [pdf]
    PRD(2022)·21 citations

Affiliations

first authorsco-authorsvia INSPIRE