pith. sign in

arxiv: 2606.11153 · v1 · pith:KYCKX5JNnew · submitted 2026-06-09 · ⚛️ nucl-th · physics.atom-ph

Quantum Monte Carlo calculations of Zemach moments in Aleq 9 nuclei

Pith reviewed 2026-06-27 11:11 UTC · model grok-4.3

classification ⚛️ nucl-th physics.atom-ph
keywords Zemach momentslight nucleiquantum Monte Carlonuclear electromagnetic momentstwo-body currentshyperfine structurechiral effective field theory
0
0 comments X

The pith

Ab initio calculations give a Zemach radius for lithium-6 larger than atomic measurements show.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper uses quantum Monte Carlo methods together with chiral effective field theory interactions to compute Zemach radii and related electromagnetic moments in nuclei up to mass nine. It reports that the lithium-6 value exceeds the radius extracted from atomic spectroscopy, matching other recent calculations and showing the mismatch is not caused by shortcomings in a particular nuclear model. For beryllium-9 the computed radius agrees with experiment, and earlier differences are traced to an uncertain model-dependent input for the magnetic radius. The work supplies nuclear-structure inputs needed for precision atomic quantities such as hyperfine splittings that modern spectroscopy can now resolve.

Core claim

Quantum Monte Carlo evaluations with Norfolk two- and three-body interactions and two-body currents produce a Zemach radius for 6Li that is larger than the atomic extraction while yielding a value for 9Be that matches experiment; the 9Be agreement shows that prior phenomenological discrepancies originated in a model-dependent magnetic-radius input rather than in the charge or magnetization distributions themselves.

What carries the argument

Quantum Monte Carlo sampling of nuclear wave functions generated by Norfolk chiral two- and three-body forces plus two-body electromagnetic currents, used to evaluate the convolution of charge and magnetization densities that defines the Zemach radius.

If this is right

  • The discrepancy between calculated and measured Zemach radius in 6Li is established as a real physical effect rather than a modeling artifact.
  • The 9Be result shows that earlier phenomenological evaluations were limited mainly by their choice of magnetic-radius input.
  • Two-body currents are shown to be necessary for a consistent description of the magnetization distribution entering the Zemach radius.
  • The computed moments supply model-independent nuclear inputs for hyperfine-structure calculations in light atoms and muonic atoms.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Similar calculations could be extended to other light nuclei to predict Zemach moments where atomic data are absent or sparse.
  • Persistent discrepancies in 6Li may motivate joint nuclear-atomic studies to isolate whether missing higher-order currents or relativistic effects are responsible.
  • Agreement on 9Be suggests the method can be used to benchmark atomic extractions of nuclear radii in other systems.

Load-bearing premise

The Norfolk interactions and included two-body currents give accurate enough charge and magnetization distributions in these light nuclei for the Zemach moments to be reliable.

What would settle it

An independent calculation with a different set of nuclear interactions that produces a Zemach radius for 6Li matching or falling below the atomic value would falsify the claim that the discrepancy is not an artifact of the nuclear model.

Figures

Figures reproduced from arXiv: 2606.11153 by Alex Gnech, Garrett B. King, Graham Chambers-Wall, Maria Piarulli, Robert B. Wiringa, Saori Pastore, Sonia Bacca.

Figure 1
Figure 1. Figure 1: ⟨RZ⟩ values from various theoretical approaches and experimental measurements for 6Li, 7Li, and 9Be. The filled black circles are the GFMC results obtained with N3LO charge and current operators for this interaction. The error bars on these calculations are estimated from the spread of the VMC calculations in this work using different nuclear models. The open purple diamonds represent the values using the … view at source ↗
Figure 2
Figure 2. Figure 2: The moment ⟨R 3 E ⟩(2) from GFMC with the N3LO charge operator (filled black circles) compared with values extracted from electron scattering measurements of the 3He and 4He charge form factors (orange squares). The theoretical error bars are from the estimated model uncertainties based on the analysis of VMC results in [PITH_FULL_IMAGE:figures/full_fig_p005_2.png] view at source ↗
read the original abstract

Modern atomic spectroscopy has reached a level of precision at which nuclear-structure effects can no longer be neglected and must be quantified reliably. In particular, hyperfine splittings depend on the Zemach radius, which encodes the convolution of the nuclear charge and magnetization distributions. The third electric Zemach moment provides a related finite-size measure and enters the elastic two-photon-exchange contribution to the Lamb shift in muonic atoms. Here, we compute Zemach radii and other electromagnetic moments for light nuclei using quantum Monte Carlo techniques within modern \textit{ab initio} nuclear theory. Using Norfolk two- and three-body interactions derived within chiral effective field theory, we assess the model dependence and study the role of two-body currents. For $^6$Li, we obtain a Zemach radius larger than that extracted from atomic measurements, consistent with recent calculations, confirming that the discrepancy is not an artifact of the nuclear model. For $^9$Be, our results agree with experiment; the discrepancy of previous phenomenological evaluations is traced to a model-dependent input for the magnetic radius.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The manuscript reports quantum Monte Carlo calculations of Zemach radii and third electric Zemach moments for nuclei with A≤9 using the Norfolk family of chiral-EFT two- and three-nucleon interactions. Central claims are that the computed Zemach radius for 6Li exceeds the atomic-extraction value (consistent with other recent calculations, indicating the discrepancy is not a nuclear-model artifact) while the 9Be result agrees with experiment, with prior phenomenological discrepancies traced to a model-dependent magnetic-radius input. Model dependence is assessed and the role of two-body currents is examined.

Significance. If the Norfolk interactions plus two-body currents are shown to control the relevant uncertainties in the charge and magnetization distributions, the work supplies ab initio nuclear inputs that can resolve model-dependent tensions in precision atomic spectroscopy and muonic-atom Lamb shifts. The QMC framework with chiral interactions offers a systematic route to these quantities for light nuclei.

major comments (2)
  1. Abstract: the headline results for 6Li and 9Be rest on the assumption that the Norfolk interactions and included two-body currents yield sufficiently accurate point-nucleon charge and magnetization distributions for the Zemach convolution; the manuscript must supply quantitative bounds on the chiral truncation error of the magnetic operator at the momentum scales that dominate the Zemach integral.
  2. Abstract: specific numerical outcomes are stated without accompanying error bars, convergence diagnostics, or statistical uncertainties, so it is not possible to verify that the reported values and their comparison to experiment are robust.
minor comments (2)
  1. A summary table listing all computed Zemach radii (with uncertainties) for the full set of nuclei would improve readability and allow direct comparison with experiment and other calculations.
  2. Explicit discussion of the momentum range probed by the Zemach moments and its relation to the chiral cutoff employed in the Norfolk interactions would clarify the expected size of higher-order corrections.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their thorough review and valuable suggestions. We address each major comment below and plan to incorporate revisions to strengthen the manuscript.

read point-by-point responses
  1. Referee: Abstract: the headline results for 6Li and 9Be rest on the assumption that the Norfolk interactions and included two-body currents yield sufficiently accurate point-nucleon charge and magnetization distributions for the Zemach convolution; the manuscript must supply quantitative bounds on the chiral truncation error of the magnetic operator at the momentum scales that dominate the Zemach integral.

    Authors: We agree that quantitative estimates of the chiral truncation uncertainty for the magnetic operator are necessary to support the claims. The Norfolk interactions allow assessment via cutoff and order variations, which we have used for model dependence. In the revised version, we will provide explicit bounds on the truncation error for the relevant magnetic form factor contributions at momenta dominating the Zemach integral (q ~ 100-300 MeV/c), by comparing results at different chiral orders and referencing the EFT power counting. This analysis will be added to Section on electromagnetic operators and summarized in the abstract. revision: yes

  2. Referee: Abstract: specific numerical outcomes are stated without accompanying error bars, convergence diagnostics, or statistical uncertainties, so it is not possible to verify that the reported values and their comparison to experiment are robust.

    Authors: The abstract presents qualitative comparisons ('larger than', 'agrees with') rather than specific numerical values, but we acknowledge the need for transparency on uncertainties. The full manuscript includes QMC statistical errors and model-dependence bands for the computed quantities. In the revision, we will include representative error estimates in the abstract (e.g., from statistical Monte Carlo sampling and interaction variations) and explicitly reference the convergence and uncertainty sections in the main text to facilitate verification of robustness. revision: yes

Circularity Check

0 steps flagged

No significant circularity detected

full rationale

The paper computes Zemach radii and moments via independent quantum Monte Carlo evaluations on top of pre-existing Norfolk chiral-EFT interactions and two-body currents taken from prior literature. No equation in the provided text defines a reported radius or moment in terms of a quantity fitted inside this work, renames a fitted input as a prediction, or reduces the central result to a self-citation chain; the derivation chain therefore remains self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

1 free parameters · 1 axioms · 0 invented entities

The calculations rest on the Norfolk chiral EFT interactions (whose low-energy constants are fitted parameters from earlier work) and the assumption that QMC with two-body currents captures the relevant electromagnetic distributions; no new entities are introduced.

free parameters (1)
  • low-energy constants in Norfolk interactions
    Two- and three-body forces derived in chiral EFT contain parameters fitted to data in prior publications; abstract does not list their values or fitting procedure.
axioms (1)
  • domain assumption Chiral effective field theory supplies a systematic expansion for nuclear two- and three-body interactions that can be used in QMC for electromagnetic moments.
    Invoked by the choice of Norfolk interactions and the assessment of two-body currents.

pith-pipeline@v0.9.1-grok · 5737 in / 1305 out tokens · 40704 ms · 2026-06-27T11:11:13.342552+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

59 extracted references · 32 canonical work pages · 6 internal anchors

  1. [1]

    J. C. Berengut, C. Delaunay, Precision isotope-shift spec- troscopy for new physics searches and nuclear insights, Nature Rev. Phys. 7 (2) (2025) 119–125.doi:10.1038/ s42254-024-00793-2

  2. [2]

    M. S. Safronova, D. Budker, D. DeMille, D. F. J. Kimball, A. Derevianko, C. W. Clark, Search for new physics with atoms and molecules, Rev. Mod. Phys. 90 (2018) 025008. doi:10.1103/RevModPhys.90.025008. URLhttps://link.aps.org/doi/10.1103/ RevModPhys.90.025008

  3. [3]

    A. C. Zemach, Proton structure and the hyperfine shift in hydrogen, Physical Review 104 (1956) 1771–1781.doi: 10.1103/PhysRev.104.1771

  4. [4]

    J. L. Friar, Nuclear finite-size effects in light muonic atoms, Annals of Physics 122 (1979) 151–196.doi: 10.1016/0003-4916(79)90200-2

  5. [5]

    C. Ji, S. Bacca, N. Barnea, O. J. Hernandez, N. Nevo-Dinur,Abinitiocalculation of nuclear struc- ture corrections in muonic atoms, J. Phys. G 45 (9) (2018) 093002.arXiv:1806.03101,doi:10.1088/ 1361-6471/aad3eb

  6. [6]

    Ohayon, A

    B. Ohayon, A. Abeln, S. Bara, T. E. Cocolios, O. Eizenberg, A. Fleischmann, L. Gastaldo, C. God- inho, M. Heines, D. Hengstler, G. Hupin, P. Indeli- cato, K. Kirch, A. Knecht, D. Kreuzberger, J. Machado, P. Navratil, N. Paul, R. Pohl, D. Unger, S. V ogiatzi, K. von Schoeler, F. Wauters, Towards precision muonic x-ray measurements of charge radii of light ...

  7. [7]

    V . A. Yerokhin, Hyperfine structure of li and be+, Phys. Rev. A 78 (2008) 012513.doi: 10.1103/PhysRevA.78.012513. URLhttps://link.aps.org/doi/10.1103/ PhysRevA.78.012513

  8. [8]

    Qi, P.-P

    X.-Q. Qi, P.-P. Zhang, Z.-C. Yan, G. W. F. Drake, Z.-X. Zhong, T.-Y . Shi, S.-L. Chen, Y . Huang, H. Guan, K.-L. Gao, Precision calculation of hyperfine structure and the zemach radii of 6,7Li + ions, Phys. Rev. Lett. 125 (2020) 183002.doi:10.1103/PhysRevLett.125.183002. URLhttps://link.aps.org/doi/10.1103/ PhysRevLett.125.183002

  9. [9]

    Sun, P.-P

    W. Sun, P.-P. Zhang, P.-p. Zhou, S.-l. Chen, Z.-q. Zhou, Y . Huang, X.-Q. Qi, Z.-C. Yan, T.-Y . Shi, G. W. F. Drake, Z.-X. Zhong, H. Guan, K.-l. Gao, Measurement of hyperfine structure and the zemach radius in 6li+ using optical ramsey technique, Phys. Rev. Lett. 131 (2023) 103002.doi:10.1103/PhysRevLett.131.103002. URLhttps://link.aps.org/doi/10.1103/ Ph...

  10. [10]

    Y . Yang, E. Epelbaum, C. Ji, P. Zhao, Zemach radii and nuclear structure effects in hyperfine splitting of Lithium (9 2025).arXiv:2509.01303

  11. [11]

    Puchalski, K

    M. Puchalski, K. Pachucki, Ground state hy- perfine splitting in 6,7Li atoms and the nuclear structure, Phys. Rev. Lett. 111 (2013) 243001. doi:10.1103/PhysRevLett.111.243001. URLhttps://link.aps.org/doi/10.1103/ PhysRevLett.111.243001

  12. [12]

    Puchalski, K

    M. Puchalski, K. Pachucki, Ground-state hyperfine splitting in the be + ion, Phys. Rev. A 89 (2014) 032510. doi:10.1103/PhysRevA.89.032510. URLhttps://link.aps.org/doi/10.1103/ PhysRevA.89.032510

  13. [13]

    Dickopf, B

    S. Dickopf, B. Sikora, A. Kaiser, M. Müller, S. Ulmer, V . A. Yerokhin, Z. Harman, C. H. Keitel, A. Mooser, K. Blaum, Precision spectroscopy on 9be overcomes lim- itations from nuclear structure, Nature 632 (8026) (2024) 757–761.doi:10.1038/s41586-024-07795-1. URLhttp://dx.doi.org/10.1038/ s41586-024-07795-1

  14. [14]

    Nevo Dinur, O

    N. Nevo Dinur, O. J. Hernandez, S. Bacca, N. Barnea, C. Ji, S. Pastore, M. Piarulli, R. B. Wiringa, Zemach mo- ments and radii of 2,3H and 3,4He, Phys. Rev. C99 (3) (2019) 034004.arXiv:1812.10261,doi:10.1103/ PhysRevC.99.034004

  15. [15]

    Carlson, S

    J. Carlson, S. Gandolfi, F. Pederiva, S. C. Pieper, R. Schi- avilla, K. E. Schmidt, R. B. Wiringa, Quantum Monte Carlo methods for nuclear physics, Rev. Mod. Phys. 87 (2015) 1067.arXiv:1412.3081,doi:10.1103/ RevModPhys.87.1067. 6

  16. [16]

    Gandolfi, D

    S. Gandolfi, D. Lonardoni, A. Lovato, M. Piarulli, Atomic nuclei from quantum Monte Carlo calculations with chiral EFT interactions (2020).arXiv:2001.01374

  17. [17]

    Piarulli, L

    M. Piarulli, L. Girlanda, R. Schiavilla, A. Kievsky, A. Lovato, L. E. Marcucci, S. C. Pieper, M. Viviani, R. B. Wiringa, Local chiral potentials with∆-intermediate states and the structure of light nuclei, Phys. Rev. C94 (5) (2016) 054007.arXiv:1606.06335,doi:10.1103/ PhysRevC.94.054007

  18. [18]

    Light-nuclei spectra from chiral dynamics

    M. Piarulli, et al., Light-nuclei spectra from chiral dynamics, Phys. Rev. Lett. 120 (5) (2018) 052503. arXiv:1707.02883,doi:10.1103/PhysRevLett. 120.052503

  19. [19]

    Local chiral interactions, the tritium Gamow-Teller matrix element, and the three-nucleon contact term

    A. Baroni, et al., Local chiral interactions, the tritium Gamow-Teller matrix element, and the three-nucleon con- tact term, Phys. Rev. C98 (4) (2018) 044003.arXiv: 1806.10245,doi:10.1103/PhysRevC.98.044003

  20. [20]

    Two-pion exchange electromagnetic current in chiral effective field theory using the method of unitary transformation

    S. Kolling, E. Epelbaum, H. Krebs, U. G. Meissner, Two- pion exchange electromagnetic current in chiral effective field theory using the method of unitary transformation, Phys. Rev. C80 (2009) 045502.arXiv:0907.3437,doi: 10.1103/PhysRevC.80.045502

  21. [21]

    Two-nucleon electromagnetic current in chiral effective field theory: one-pion exchange and short-range contributions

    S. Kolling, E. Epelbaum, H. Krebs, U. G. Meissner, Two- nucleon electromagnetic current in chiral effective field theory: One-pion exchange and short-range contributions, Phys. Rev. C84 (2011) 054008.arXiv:1107.0602,doi: 10.1103/PhysRevC.84.054008

  22. [22]

    Pastore, R

    S. Pastore, R. Schiavilla, J. L. Goity, Electromagnetic two-body currents of one- and two-pion range, Phys. Rev. C78 (2008) 064002.arXiv:0810.1941,doi:10.1103/ PhysRevC.78.064002

  23. [24]

    Pastore, L

    S. Pastore, L. Girlanda, R. Schiavilla, M. Viviani, The two-nucleon electromagnetic charge operator in chiral ef- fective field theory (χEFT) up to one loop, Phys. Rev. C84 (2011) 024001.arXiv:1106.4539,doi:10.1103/ PhysRevC.84.024001

  24. [25]

    Gnech, R

    A. Gnech, R. Schiavilla, Magnetic structure of few- nucleon systems at high momentum transfers in a chi- ral effective field theory approach, Phys. Rev. C 106 (4) (2022) 044001.arXiv:2207.05528,doi:10.1103/ PhysRevC.106.044001

  25. [26]

    Miyagi, X

    T. Miyagi, X. Cao, R. Seutin, S. Bacca, R. F. Garcia Ruiz, K. Hebeler, J. D. Holt, A. Schwenk, Impact of Two-Body Currents on Magnetic Dipole Moments of Nuclei, Phys. Rev. Lett. 132 (23) (2024) 232503.arXiv:2311.14383, doi:10.1103/PhysRevLett.132.232503

  26. [27]

    Chambers-Wall, A

    G. Chambers-Wall, A. Gnech, G. B. King, S. Pas- tore, M. Piarulli, R. Schiavilla, R. B. Wiringa, Quan- tum Monte Carlo Calculations of Magnetic Form Fac- tors in Light Nuclei, Phys. Rev. Lett. 133 (21) (2024) 212501.arXiv:2407.03487,doi:10.1103/ PhysRevLett.133.212501

  27. [28]

    Chambers-Wall, A

    G. Chambers-Wall, A. Gnech, G. B. King, S. Pastore, M. Piarulli, R. Schiavilla, R. B. Wiringa, Magnetic struc- ture of A≤10 nuclei using the Norfolk nuclear models with quantum Monte Carlo methods, Phys. Rev. C 110 (5) (2024) 054316.arXiv:2407.04744,doi:10.1103/ PhysRevC.110.054316

  28. [29]

    G. B. King, G. Chambers-Wall, A. Gnech, S. Pastore, M. Piarulli, R. B. Wiringa, Longitudinal form factors of A≤10 nuclei in a chiral effective field theory approach, Phys. Rev. C 110 (5) (2024) 054325.arXiv:2408. 16909,doi:10.1103/PhysRevC.110.054325

  29. [30]

    X.-X. Sun, V . Baru, A. A. Filin, E. Epelbaum, H. Krebs, U.-G. Meißner, A. Nogga, Ab initio charge form factors and radii of light isoscalar nuclei: Role of the two-body charge density (2026).arXiv:2601.09614. URLhttps://arxiv.org/abs/2601.09614

  30. [31]

    G. B. King, S. Pastore, M. Piarulli, R. Schiavilla, Partial muon capture rates in A=3 and A=6 nu- clei with chiral effective field theory, Phys. Rev. C 105 (4) (2022) L042501.arXiv:2111.11360, doi:10.1103/PhysRevC.105.L042501. URLhttps://link.aps.org/doi/10.1103/ PhysRevC.105.L042501

  31. [32]

    J. M. Bub, M. Piarulli, R. J. Furnstahl, S. Pastore, D. R. Phillips, Bayesian analysis of nucleon-nucleon scattering data in pionless effective field theory (8 2024).arXiv: 2408.02480

  32. [33]

    Somasundaram, J

    R. Somasundaram, J. E. Lynn, L. Huth, A. Schwenk, I. Tews, Maximally local two-nucleon interactions at N3LO in∆-less chiral effective field theory, Phys. Rev. C 109 (3) (2024) 034005.arXiv:2306.13579,doi: 10.1103/PhysRevC.109.034005

  33. [34]

    Sousa, C

    R. Somasundaram, C. L. Armstrong, P. Giuliani, K. God- bey, S. Gandolfi, I. Tews, Emulators for scarce and noisy data: Application to auxiliary field diffusion Monte Carlo for the deuteron, Phys. Lett. B 866 (2025) 139558.arXiv:2404.11566,doi:10.1016/j. physletb.2025.139558

  34. [35]

    C. L. Armstrong, P. Giuliani, K. Godbey, R. Somasun- daram, I. Tews, Emulators for Scarce and Noisy Data: Application to Auxiliary-Field Diffusion Monte Carlo for Neutron Matter, Phys. Rev. Lett. 135 (14) (2025) 142501. arXiv:2502.03680,doi:10.1103/9928-wyjm

  35. [36]

    Amroun, et al., H-3 and He-3 electromagnetic form- factors, Nucl

    A. Amroun, et al., H-3 and He-3 electromagnetic form- factors, Nucl. Phys. A579 (1994) 596–626.doi:10. 1016/0375-9474(94)90925-3. 7

  36. [37]

    J. E. Purcell, J. H. Kelley, E. Kwan, C. G. Sheu, H. R. Weller, Energy levels of light nuclei A=3, Nucl. Phys. A848 (2010) 1–74.doi:10.1016/j.nuclphysa.2010. 08.012

  37. [38]

    Sick, Zemach moments of 3He and 4He, Phys

    I. Sick, Zemach moments of 3He and 4He, Phys. Rev. C 90 (2014) 064002.doi:10.1103/PhysRevC.90.064002. URLhttps://link.aps.org/doi/10.1103/ PhysRevC.90.064002

  38. [39]

    Shiner, R

    D. Shiner, R. Dixson, V . Vedantham, Three-Nucleon Charge Radius: A Precise Laser Determination Using He- 3, Phys. Rev. Lett. 74 (1995) 3553–3556.doi:10.1103/ PhysRevLett.74.3553

  39. [40]

    J. J. Krauth, et al., Measuring theα-particle charge radius with muonic helium-4 ions, Nature 589 (7843) (2021) 527–531.doi:10.1038/s41586-021-03183-1

  40. [41]

    Nortershauser, T

    W. Nortershauser, T. Neff, R. Sanchez, I. Sick, Charge radii and ground state structure of lithium isotopes: Ex- periment and theory reexamined, Phys. Rev. C84 (2011) 024307.doi:10.1103/PhysRevC.84.024307

  41. [42]

    De Jager, H

    C. De Jager, H. De Vries, C. De Vries, Nuclear charge- and magnetization-density-distribution param- eters from elastic electron scattering, Atomic Data and Nuclear Data Tables 14 (5) (1974) 479–508, nu- clear Charge and Moment Distributions.doi:https: //doi.org/10.1016/S0092-640X(74)80002-1. URLhttps://www.sciencedirect.com/science/ article/pii/S0092640X74800021

  42. [43]

    D. R. Tilley, C. M. Cheves, J. L. Godwin, G. M. Hale, H. M. Hofmann, J. H. Kelley, C. G. Sheu, H. R. Weller, Energy levels of light nuclei A=5, A=6, A=7, Nucl. Phys. A708 (2002) 3–163.doi:10.1016/S0375-9474(02) 00597-3

  43. [44]

    J. A. Jansen, R. T. Peerdeman, C. De Vries, Nuclear charge radii of 12 C and 9 Be, Nucl. Phys. A 188 (1972) 337–352.doi:10.1016/0375-9474(72)90062-0

  44. [45]

    D. R. Tilley, J. H. Kelley, J. L. Godwin, D. J. Millener, J. E. Purcell, C. G. Sheu, H. R. Weller, Energy levels of light nuclei A=8,9,10, Nucl. Phys. A745 (2004) 155–362. doi:10.1016/j.nuclphysa.2004.09.059

  45. [46]

    See supplementary material

  46. [47]

    Door, et al., Probing New Bosons and Nuclear Struc- ture with Ytterbium Isotope Shifts, Phys

    M. Door, et al., Probing New Bosons and Nuclear Struc- ture with Ytterbium Isotope Shifts, Phys. Rev. Lett. 134 (6) (2025) 063002.arXiv:2403.07792,doi:10. 1103/PhysRevLett.134.063002

  47. [48]

    Miyagi, M

    T. Miyagi, M. Heinz, A. Schwenk, Ab initio computations of the fourth-order charge density moments of 48Ca and 208Pb (8 2025).arXiv:2508.10767

  48. [49]

    Hiyama, T

    E. Hiyama, T. Suzuki, Moments of the Charge Distribu- tion Observed through Electron Scattering in 3H and 3He, PTEP 2024 (8) (2024) 083D02.arXiv:2406.17394, doi:10.1093/ptep/ptae126

  49. [50]

    K. M. Nollett, R. B. Wiringa, R. Schiavilla, A Six body calculation of the alpha deuteron radiative cap- ture cross-section, Phys. Rev. C63 (2001) 024003. arXiv:nucl-th/0006064,doi:10.1103/PhysRevC. 63.024003

  50. [51]

    K. M. Nollett, Radiative alpha capture cross-sections from realistic nucleon-nucleon interactions and varia- tional Monte Carlo wave functions, Phys. Rev. C63 (2001) 054002.arXiv:nucl-th/0102022,doi:10.1103/ PhysRevC.63.054002

  51. [52]

    A. R. Flores, K. M. Nollett, Variational Monte Carlo calculations of n+H3 scattering, Phys. Rev. C 108 (3) (2023) 034001.arXiv:2209.00093,doi:10.1103/ PhysRevC.108.034001

  52. [53]

    A. R. Flores, K. M. Nollett, M. Piarulli, Quantum Monte Carlo calculations of neutron-αscattering via an integral relation, Phys. Rev. C 112 (1) (2025) 014008.arXiv: 2502.18718,doi:10.1103/q4dy-vhv1

  53. [54]

    Lovato, S

    A. Lovato, S. Gandolfi, J. Carlson, S. C. Pieper, R. Schiavilla, Electromagnetic response of 12C: A first-principles calculation, Phys. Rev. Lett. 117 (8) (2016) 082501.arXiv:1605.00248,doi:10.1103/ PhysRevLett.117.082501

  54. [55]

    Ab initio calculation of neutral-current $\nu$-$^{12}$C inclusive quasielastic scattering

    A. Lovato, S. Gandolfi, J. Carlson, E. Lusk, S. C. Pieper, R. Schiavilla, Quantum Monte Carlo calculation of neutral-currentν− 12 Cinclusive quasielastic scattering, Phys. Rev. C 97 (2) (2018) 022502.arXiv:1711.02047, doi:10.1103/PhysRevC.97.022502

  55. [56]

    Lovato, J

    A. Lovato, J. Carlson, S. Gandolfi, N. Rocco, R. Schi- avilla, Ab initio study of(ν ℓ, ℓ−)and( νℓ, ℓ+)inclusive scattering in 12C: confronting the MiniBooNE and T2K CCQE data (3 2020).arXiv:2003.07710

  56. [57]

    P. Zhao, Y . Yang, C. Ji, Private communication (2026)

  57. [58]

    G. B. King, G. Chambers-Wall, A. Gnech, S. Pastore, M. Piarulli, R. B. Wiringa, Electromagnetic radii of light nuclei from variational Monte Carlo calculations, Phys. Rev. C 112 (4) (2025) L041302.arXiv:2504.04201, doi:10.1103/w8kj-p8bv

  58. [59]

    M. L. Bissell, et al., Interrogating the composition and distribution of nuclear magnetization via the hyperfine anomaly: experiment meets nuclear and atomic theory for short-lived 47K (3 2026).arXiv:2603.20090

  59. [60]

    S. G. Wilkins, et al., Observation of the distribution of nuclear magnetization in a molecule, Science 390 (6771) (2025) adm7717.arXiv:2311.04121,doi:10.1126/ science.adm7717. 8 Supplementary Material In order to estimate the model uncertainty on the more com- putationally intensive GFMC calculations, we performed VMC calculations with several nuclear mod...