Origin of the nucleon gravitational form factor <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:msub> <mml:mi>B</mml:mi> <mml:mi>N</mml:mi> </mml:msub> <mml:mo stretchy="false">(</mml:mo> <mml:mi>t</mml:mi> <mml:mo str
Recent lattice QCD simulations and phenomenological models indicate that the nucleon’s gravitational form factor <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:msub> <a:mi>B</a:mi> <a:mi>N</a:mi> </a:msub> <a:mo stretchy="false">(</a:mo> <a:mi>t</a:mi> <a:mo stretchy="false">)</a:mo> </a:math> remains remarkably small at finite momentum transfer <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"> <e:mi>t</e:mi> </e:math> . While <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"> <g:msub> <g:mi>B</g:mi> <g:mi>N</g:mi> </g:msub> <g:mo stretchy="false">(</g:mo> <g:mn>0</g:mn> <g:mo stretchy="false">)</g:mo> <g:mo>=</g:mo> <g:mn>0</g:mn> </g:math> is a known consequence of the equivalence principle, the physical origin of its suppression at finite <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"> <k:mi>t</k:mi> </k:math> has not been fully elucidated. In this work, we demonstrate that the smallness of <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"> <m:msub> <m:mi>B</m:mi> <m:mi>N</m:mi> </m:msub> <m:mo stretchy="false">(</m:mo> <m:mi>t</m:mi> <m:mo stretchy="false">)</m:mo> </m:math> arises from a fundamental cancellation within the nucleon’s wave functions. Using light-front holographic QCD, we show that <q:math xmlns:q="http://www.w3.org/1998/Math/MathML" display="inline"> <q:msub> <q:mi>B</q:mi> <q:mi>N</q:mi> </q:msub> <q:mo stretchy="false">(</q:mo> <q:mi>t</q:mi> <q:mo stretchy="false">)</q:mo> </q:math> is governed by an antisymmetric factor in the longitudinal dynamics that leads to an exact vanishing in the symmetric limit and significant suppression for realistic nucleon structures. Our results suggest that the smallness of <u:math xmlns:u="http://www.w3.org/1998/Math/MathML" display="inline"> <u:msub> <u:mi>B</u:mi> <u:mi>N</u:mi> </u:msub> <u:mo stretchy="false">(</u:mo> <u:mi>t</u:mi> <u:mo stretchy="false">)</u:mo> </u:math> is a signature of the nucleon’s dominant S-wave character, providing a formal justification for its frequent omission in practical applications like near-threshold <y:math xmlns:y="http://www.w3.org/1998/Math/MathML" display="inline"> <y:mi>J</y:mi> <y:mo>/</y:mo> <y:mi>ψ</y:mi> </y:math> production.
Authors
- Anonymous
Institutions
- University of Science and Technology of China (CN)
- Chinese Academy of Sciences (CN)
- Peng Huanwu Center for Fundamental Theory (CN)
- Institute of Theoretical Physics (CN)
- Institute of Modern Physics (CN)
- University of Chinese Academy of Sciences (CN)
- Indian Institute of Technology Kanpur (IN)
Publication Details
- Journal
- Physical review. D/Physical review. D.
- Published
- 2026-03-31
- DOI
- https://doi.org/10.1103/c9ph-w9bw
- Primary Topic
- Quantum Chromodynamics and Particle Interactions
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Natural Science Foundation of China
- Chinese Academy of Sciences