Dissecting a strongly coupled scalar nucleon

We continue our investigation of the stress within a strongly coupled scalar nucleon, and now dissect the gravitational form factors into contributions from its constituents, the (mock) nucleon and the (mock) pion. The computation is based on a nonperturbative solution of the scalar Yukawa model in the light-front Hamiltonian formalism with a Fock sector expansion, including up to one nucleon and two pions. By employing the “good currents” <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msubsup><a:mrow><a:mi>T</a:mi></a:mrow><a:mrow><a:mi>i</a:mi></a:mrow><a:mrow><a:mo>+</a:mo><a:mo>+</a:mo></a:mrow></a:msubsup></a:mrow></a:math>, <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mrow><c:msubsup><c:mrow><c:mi>T</c:mi></c:mrow><c:mrow><c:mi>i</c:mi></c:mrow><c:mrow><c:mo>+</c:mo><c:mo>−</c:mo></c:mrow></c:msubsup></c:mrow></c:math> and <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:msubsup><e:mi>T</e:mi><e:mi>i</e:mi><e:mn>12</e:mn></e:msubsup></e:math>, we extract the full set of gravitational form factors <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"><g:msub><g:mi>A</g:mi><g:mi>i</g:mi></g:msub></g:math>, <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"><i:msub><i:mi>D</i:mi><i:mi>i</i:mi></i:msub></i:math>, <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"><k:msub><k:mover accent="true"><k:mi>c</k:mi><k:mo stretchy="false">¯</k:mo></k:mover><k:mi>i</k:mi></k:msub></k:math> without the contamination of the spurious form factors and free of uncanceled UV divergences. With these results, we decompose the mass of the system into its constituents and compute the matter and mechanical radii, gaining insights into the strongly coupled system. Published by the American Physical Society 2024