Local-nuclear-density dependent calculation of nucleon electromagnetic form factor ratios in finite nuclei
Abstract
We calculate the electromagnetic form factors of nucleons bound in finite nuclei and make predictions to the ratio between the electric (GE*) and magnetic (GM*) form factors in terms of the square of the four-momentum transfer Q2. We extend our previous constant-density calculations within the covariant spectator-QMC framework by incorporating the spatial nuclear density profiles of finite nuclei and quantify the deviations from the average-density approximation used in our previous applications. The impact of the medium effects can then be observed considering the ratio between GE*/GM* and the ratio in free space GE/GM, that define the proton electromagnetic double ratio associated with a given nucleus. The double ratio is expected to remove some systematic uncertainties. There is the expectation that ratios GE*/GM* associated with the bound protons inside the nucleus will be measured in the near future in polarization-transfer experiments (e⃗ A, e' A' p⃗). Anticipating future measurements on the subject, we make predictions for the double ratios, to be compared with the average measurements on the energy states of protons bound to nuclei. We consider the nuclei 12C, 16O and 40Ca. We conclude that the form factors calculated using nuclear density profile function ρ(r) are less suppressed than in the case of the results calculated using the average nuclear density. The results indicate that the relative importance of the low-density surface region increases with Q2, leading to a weaker suppression than that predicted by the average-density approximation. We also make predictions for the ratios associated with neutrons bound to nuclei.
Related
- Microscopic Statistical Calculation of Nuclear Level Density Based on Relativistic Density Functional Theory
- Coulomb and nuclear polarization of the nucleon density in the dinuclear configuration of the 40Ca + 208Pb system
- Short-range correlated pairs from nucleon density profiles as a new probe of the nuclear equation of state
- Lattice QCD calculation of the pion-nucleon coupling g̅0 induced by the QCD Θ-term
- Configuration-interaction time-dependent density functional theory for nuclear dynamics
BibTeX
@misc{ramalho2026localnucleardensity,
title = {{Local-nuclear-density dependent calculation of nucleon electromagnetic form factor ratios in finite nuclei}},
author = {G. Ramalho and K. Tsushima and Myung-Ki Cheoun},
howpublished = {arXiv},
year = {2026},
month = aug,
doi = {10.48550/arxiv.2608.29358},
eprint = {2608.29358},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.29358},
}
RIS
TY - UNPB
TI - Local-nuclear-density dependent calculation of nucleon electromagnetic form factor ratios in finite nuclei
AU - G. Ramalho
AU - K. Tsushima
AU - Myung-Ki Cheoun
PY - 2026
DA - 2026/08/29
PB - arXiv
DO - 10.48550/arxiv.2608.29358
UR - https://arxiv.org/abs/2608.29358
AB - We calculate the electromagnetic form factors of nucleons bound in finite nuclei and make predictions to the ratio between the electric (G_E^*) and magnetic (G_M^*) form factors in terms of the square of the four-momentum transfer Q^2. We extend our previous constant-density calculations within the covariant spectator-QMC framework by incorporating the spatial nuclear density profiles of finite nuclei and quantify the deviations from the average-density approximation used in our previous applications. The impact of the medium effects can then be observed considering the ratio between G_E^*/G_M^* and the ratio in free space G_E/G_M, that define the proton electromagnetic double ratio associated with a given nucleus. The double ratio is expected to remove some systematic uncertainties. There is the expectation that ratios G_E^*/G_M^* associated with the bound protons inside the nucleus will be measured in the near future in polarization-transfer experiments (e⃗ A, e' A' p⃗). Anticipating future measurements on the subject, we make predictions for the double ratios, to be compared with the average measurements on the energy states of protons bound to nuclei. We consider the nuclei ^12C, ^16O and ^40Ca. We conclude that the form factors calculated using nuclear density profile function ρ(r) are less suppressed than in the case of the results calculated using the average nuclear density. The results indicate that the relative importance of the low-density surface region increases with Q^2, leading to a weaker suppression than that predicted by the average-density approximation. We also make predictions for the ratios associated with neutrons bound to nuclei.
ER -