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arXiv · 2506.02597

Ab initio study of the radii of oxygen isotopes

Zhengxue Ren·Serdar Elhatisari·Ulf-G. Meißner
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Abstract

We present an {\em ab initio} study of the charge and matter radii of oxygen isotopes from $^{16}$O to $^{20}$O using nuclear lattice effective field theory (NLEFT) with high-fidelity N$^3$LO chiral interactions. To efficiently address the Monte Carlo sign problem encountered in nuclear radius calculations, we introduce the {\em partial pinhole algorithm}, significantly reducing statistical uncertainties and extending the reach to more neutron-rich and proton-rich isotopes. Our computed charge radii for $^{16}$O, $^{17}$O, and $^{18}$O closely match experimental data, and we predict a charge radius of $2.810(32)$ fm for $^{20}$O. The calculated matter radii show excellent agreement with values extracted from low-energy proton and electron elastic scattering data, but are inconsistent with those derived from interaction cross sections and charge-changing cross section measurements. These discrepancies highlight model-dependent ambiguities in the experimental extraction methods of matter radii and underscore the value of precise theoretical benchmarks from NLEFT calculations.

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Zhengxue Ren, Serdar Elhatisari, Ulf-G. Meißner. 2025-06-03. Ab initio study of the radii of oxygen isotopes. https://doi.org/10.1103/y6s2-43ym

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