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Nuclear Theory·nucl-th

Thursday·January 25, 2024

9 papers—4 primary·5 cross-listed

All9Primary4Cross-lists5
  1. 01

    [Submitted on 24 Jan 2024]

    Revisiting the helium isotope-shift puzzle with improved uncertainties from nuclear structure corrections

    Simone Salvatore Li Muli · Thomas R. Richardson · Sonia Bacca

    Measurements of the difference between the squared charge radii of the helion (He nucleus) and the -particle (He nucleus) have been characterized by longstanding tensions, recently spotlighted in the 3.6 discrepancy of the extractions from ordinary atoms versus those from muonic atoms. Here, we present a novel analysis of uncertainties in nuclear structure corrections that must be supplied by theory to enable the extraction of the difference in radii from spectroscopic experiments. We use modern Bayesian inference techniques to quantify uncertainties stemming from the truncation of the chiral effective field theory expansion of the nuclear force for both muonic and ordinary atoms. With the new nuclear structure input, the helium isotope-shift puzzle cannot be explained, rather it is reinforced to a 4 discrepancy.

    Comments:
    5 pages, 3 figures, 2 tables
    Subjects:
    Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
    arXiv:
    2401.13424 [pdf]
    PRL(2025)·13 citations
  2. 02

    [Submitted on 24 Jan 2024]

    Neutron star matter as a dilute solution of protons in neutrons

    J. Keller · K. Hebeler · C. J. Pethick · A. Schwenk

    Neutron stars contain neutron-rich matter with around 5% protons at nuclear saturation density. In this Letter, we consider equilibrium between bulk phases of matter based on asymmetric nuclear matter calculations using chiral effective field theory interactions rather than, as has been done in the past, by interpolation between the properties of symmetric nuclear matter and pure neutron matter. Neutron drip (coexistence of nuclear matter with pure neutrons) is well established, but from earlier work it is unclear whether proton drip (equilibrium between two phases, both of which contain protons and neutrons) is possible. We find that proton drip is a robust prediction of any physically reasonable equation of state, but that it occurs over a limited region of densities and proton fractions. An analytical model based on expanding the energy in powers of the proton density, rather than the neutron excess, is able to account for these features of the phase diagram.

    Comments:
    6 pages, 4 figures, published version
    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Experiment (nucl-ex)
    arXiv:
    2401.13461 [pdf]
    PRL(2024)·11 citations
  3. 03

    [Submitted on 24 Jan 2024]

    Effects of dilute neutron matter on the neutron star crust equation of state

    Guilherme Grams🇧🇪 · Jerome Margueron🇫🇷

    We develop a compressible liquid-drop model to describe the crust of neutron stars for which the role of the nuclear clusters, the neutron gas, and the electrons are clearly identified. The novelty relies on the contribution of the neutron gas, which is qualitatively adjusted to reproduce 'ab initio' predictions in dilute neutron matter. We relate the properties of dilute neutron matter to the ones of neutron stars crust and we compare the mean-field approximation to an improved approach that better describes dilute neutron matter. The latter is quite sensitive to the unitary limit, a universal feature of Fermi systems having a large value of the scattering length and a small interaction range. While the impact of the accurate description of dilute neutron matter is important in uniform matter (up to 30\% corrections with respect to a mean-field calculations), we find a reduction of this impact in the context of the crust of neutron stars due to the additional matter components (nuclear clusters and electrons). In agreement with our previous works, dilute neutron matter is however a necessary ingredient for accurate predictions of the properties of the crust of neutron stars.

    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
    arXiv:
    2401.13590 [pdf]
    EPJA(2024)·4 citations
  4. 04

    [Submitted on 24 Jan 2024]

    Relativistic meson-exchange currents in semi-inclusive lepton scattering

    Valerio Belocchi🇮🇹 · Maria Benedetta Barbaro🇮🇹 · Arturo De Pace🇮🇹 · Marco Martini🇫🇷

    We assess the impact of two-particle--two-hole excitations on the semi-inclusive electron scattering process (e,e'p) using a fully relativistic nuclear model calculation that precisely incorporates antisymmetrization. The calculation encompasses all contributions involving the exchange of a single pion and the excitation of a Delta resonance. Our results are compared with (e,e'p) data on carbon at kinematics where two-nucleon emission dominates. This work represents an essential step towards the microscopic computation of the two-particle--two-hole contribution to semi-inclusive neutrino reactions, crucial in the analysis of neutrino oscillation experiments.

    Comments:
    14 pages, 10 figures
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2401.13640 [pdf]
    PRC(2024)·9 citations
  5. 05

    [Submitted on 23 Jan 2024] (cross-list from quant-ph)

    Quantum error mitigation for Fourier moment computation

    Oriel Kiss🇨🇭 · Michele Grossi🇨🇭 · Alessandro Roggero🇮🇹

    Hamiltonian moments in Fourier space - expectation values of the unitary evolution operator under a Hamiltonian at different times - provide a convenient framework to understand quantum systems. They offer insights into the energy distribution, higher-order dynamics, response functions, correlation information and physical properties. This paper focuses on the computation of Fourier moments within the context of a nuclear effective field theory on superconducting quantum hardware. The study integrates echo verification and noise renormalization into Hadamard tests using control reversal gates. These techniques, combined with purification and error suppression methods, effectively address quantum hardware decoherence. The analysis, conducted using noise models, reveals a significant reduction in noise strength by two orders of magnitude. Moreover, quantum circuits involving up to 266 CNOT gates over five qubits demonstrate high accuracy under these methodologies when run on IBM superconducting quantum devices.

    Comments:
    12 pages, 7 pages appendix, comments are welcome
    Subjects:
    Quantum Physics (quant-ph); Nuclear Theory (nucl-th)
    arXiv:
    2401.13048 [pdf]
    PRD(2025)·20 citations
  6. 06

    [Submitted on 18 Dec 2023] (cross-list from hep-ph)

    Can we measure Double DVCS at JLab and the EIC?

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

    Double deeply virtual Compton scattering (DDVCS) is a very precise tool for the nucleon tomography. Its measurement requires high luminosity electron beams and precise dedicated detectors, since its amplitude is quite small in the interesting kinematical domain where collinear QCD factorization allows the extraction of quark and gluon generalized parton distributions (GPDs). We analyze the prospects for its study in the JLab energy domain as well as in higher energy electron-ion colliders. Our results are very encouraging for various observables both with an unpolarized and polarized lepton beam. Using various realistic models for GPDs, we demonstrate that DDVCS measurements are indeed very sensitive to their behaviour. Implementing our lowest order cross-section formulae in the EpIC Monte Carlo generator, we estimate the expected number of interesting events.

    Comments:
    6 pages, 5 figures, 1 table, conference proceedings for the 25th International Spin Physics Symposium (SPIN 2023)
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
    arXiv:
    2401.13064 [pdf]
    PoS(2024)·3 citations
  7. 07

    [Submitted on 23 Jan 2024] (cross-list from hep-ph)

    Collectivity inside high-multiplicity jets in high-energy proton-proton collisions

    Wenbin Zhao🇺🇸 · Zi-Wei Lin🇺🇸 · Xin-Nian Wang🇺🇸

    We present the first study of collectivity inside jets with high charged multiplicity in proton-proton collisions at the Large Hadron Collider. By incorporating final-state partonic and hadronic interactions through cascade models among jet shower partons and final hadrons, we investigate and compare to the CMS experimental data on multiplicity distribution, pseudorapidity distribution, and elliptic anisotropy coefficient of two-particle correlations within the jet. We show that final-state partonic interactions are essential for producing the flow-like long-range correlation, which leads to the enhanced tail in the dependence of above the non-flow correlation from jet parton showering at high multiplicities () as observed in the CMS experimental data. In addition, we provide predictions for the pseudorapidity-gap dependence of that can be tested in future experimental measurements.

    Comments:
    6 pages, 4 fiures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2401.13137 [pdf]
    11 citations
  8. 08

    [Submitted on 24 Jan 2024] (cross-list from hep-ph)

    Extracting transition generalized parton distributions from hard exclusive pion-nucleon scattering

    Jian-Wei Qiu🇺🇸 · Zhite Yu🇺🇸

    We study the extraction of transition generalized parton distributions (GPDs) from production of two back-to-back high transverse momentum photons () and a massive pair of leptons () in hard exclusive pion-nucleon scattering. We argue that the exclusive scattering amplitude of both processes could be factorized into nonperturbative pion distribution amplitude and nucleon transition GPDs that are convoluted with perturbatively calculable short-distance matching coefficients. We demonstrate that the exclusive diphoton production not only is complementary to the Drell-Yan-type dilepton production for extracting the GPDs, but also provides enhanced sensitivities for extracting the parton momentum fraction dependence of the GPDs. We show that both exclusive observables are physically measurable at the J-PARC and AMBER experiment energies. If the target nucleon can be polarized, corresponding spin asymmetries can offer additional sensitivities for extracting transition GPDs.

    Comments:
    7+2 pages, 9 figures; journal published version
    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:
    2401.13207 [pdf]
    PRD(2024)·22 citations
  9. 09

    [Submitted on 24 Jan 2024] (cross-list from hep-ph)

    Theoretical aspects of relativistic spin hydrodynamics coupled with electromagnetic fields

    Rajeev Singh🇺🇸 · Masoud Shokri🇩🇪 · S. M. A. Tabatabaee🇮🇷

    We expand the classical phase-space distribution function to incorporate couplings between spin and electromagnetic fields. This extension has led to the derivation of modified constitutive relations for the charge current, energy-momentum tensor, and spin tensor. Due to these couplings, the new tensors are revised from their perfect fluid analogues, creating an interplay between the background and spin fluid equations of motion. The corrections introduced in our framework have the potential to shed light on the experimentally observed discrepancies in the spin polarization measurements of Lambda hyperons.

    Comments:
    Contribution to SPIN 2023 conference
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2401.13465 [pdf]
    PoS(2024)·0 citations

Affiliations

first authorsco-authorsvia INSPIRE