Publication Date:
2021-03-19
Description:
The neutron is a cornerstone in our depiction of the visible universe. Despite the neutron zero-net electric charge, the asymmetric distribution of the positively- (up) and negatively-charged (down) quarks, a result of the complex quark-gluon dynamics, lead to a negative value for its squared charge radius, $$langle {r}_{{
m{n}}}^{2}
angle$$ ⟨ r n 2 ⟩ . The precise measurement of the neutron’s charge radius thus emerges as an essential part of unraveling its structure. Here we report on a $$langle {r}_{{
m{n}}}^{2}
angle$$ ⟨ r n 2 ⟩ measurement, based on the extraction of the neutron electric form factor, $${G}_{{
m{E}}}^{{
m{n}}}$$ G E n , at low four-momentum transfer squared (Q2) by exploiting the long known connection between the N → Δ quadrupole transitions and the neutron electric form factor. Our result, $$langle {r}_{{
m{n}}}^{2}
angle =-0.110pm 0.008,({{
m{fm}}}^{2})$$ ⟨ r n 2 ⟩ = − 0.110 ± 0.008 ( fm 2 ) , addresses long standing unresolved discrepancies in the $$langle {r}_{{
m{n}}}^{2}
angle$$ ⟨ r n 2 ⟩ determination. The dynamics of the strong nuclear force can be viewed through the precise picture of the neutron’s constituent distributions that result into the non-zero $$langle {r}_{{
m{n}}}^{2}
angle$$ ⟨ r n 2 ⟩ value.
Electronic ISSN:
2041-1723
Topics:
Biology
,
Chemistry and Pharmacology
,
Natural Sciences in General
,
Physics
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