Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Fujii, Daisuke; Kawaguchi, Mamiya*; Tanaka, Mitsuru*
Proceedings of Science (Internet), 500, p.239_1 - 239_6, 2026/01
Elucidating the mechanisms by which quarks and gluons are confined within hadrons is the most fundamental challenge in QCD. To solve this problem, it is important to understand the role of quark and gluon condensation and the associated spontaneous symmetry breaking in making hadrons. Recently, the stress distribution inside the proton has become experimentally measurable. It is extracted from the gravitational form factors that characterize the matrix elements of the energy-momentum tensor for the proton. This stress distribution is the force that confines quarks and gluons inside hadrons, opening the way to approach the above issues from the viewpoint of stress distribution. In this talk, we investigate the contributions of phenomena reflecting chiral and scale symmetry breaking, such as quark and gluon condensation, to the pressure distribution inside the nucleon, and show that these contributions are essential for stabilizing the nucleon.
Tanaka, Mitsuru*; Fujii, Daisuke; Kawaguchi, Mamiya*
Physical Review D, 112(5), p.054048_1 - 054048_18, 2025/09
Times Cited Count：3 Percentile：58.35(Astronomy & Astrophysics)We study the impact of the QCD scale anomaly on the gravitational form factors of the nucleon, focusing in particular on the 
form factor, the associated stress distribution, and internal force structure. Our analysis is based on a Skyrme model constructed within the framework of scale-invariant chiral perturbation theory. This model incorporates both the pion and a scalar meson, which represent the effects of the current quark mass and the gluonic quantum contributions to the scale anomaly, respectively. By varying the scalar meson mass, we investigate how the gluonic part of the scale anomaly affects the mechanical properties of the nucleon. We find that the gluonic contribution is essential for satisfying the stability conditions of the nucleon and generating the confining pressure. We also calculate the momentum-transfer dependence of , and the result shows good agreement with lattice QCD.
Fujii, Daisuke; Kawaguchi, Mamiya*; Tanaka, Mitsuru*
Physics Letters B, 866, p.139559_1 - 139559_7, 2025/07
Times Cited Count：10 Percentile：98.32(Astronomy & Astrophysics)We investigate the confining pressure inside the nucleon and the associated gravitational form factor, known as the D-term, within a skyrmion based on the scale-invariant chiral perturbation theory. In this approach, the effects of scale symmetry breaking are incorporated through the coupling of a scalar meson field to the scale anomaly, following the low-energy theorem. Utilizing the decomposition of the nucleon's energy-momentum tensor, we clarify how the scale anomaly components contribute to the internal pressure. Our analysis reveals that the gluon-induced scale anomaly predominantly governs the confining pressure. Compared to the result in the chiral limit of conventional chiral perturbation theory, this approach yields a total pressure profile more consistent with lattice QCD data. Furthermore, the pressure due to the gluonic anomaly extends over a wide spatial region, leading to a significant contribution to the D-term.
Fujii, Daisuke; Kawaguchi, Mamiya*; Tanaka, Mitsuru*
no journal, ,
Elucidating the mechanism by which quarks and gluons are confined inside hadrons is one of the most fundamental problems in QCD. Addressing this issue requires understanding the roles of the quark and gluon condensates and the associated spontaneous symmetry breaking in hadron formation. Recently, the stress distribution inside the proton has become experimentally accessible, extracted from the gravitational form factors that characterize matrix elements of the energy-momentum tensor. Because this stress distribution represents the confining forces that bind quarks and gluons inside hadrons, it opens a new avenue to the problem from the perspective of internal forces. In this talk, by examining how phenomena such as the quark and gluon condensates contribute to the pressure distribution inside the nucleon, I will show that these effects are indispensable for its stability.
Fujii, Daisuke; Kawaguchi, Mamiya*; Tanaka, Mitsuru*
no journal, ,
Elucidating how quarks and gluons are confined in hadrons is a central challenge in QCD. Progress requires clarifying the roles of non-perturbative phenomena, chiral and gluon condensates and the associated spontaneous and anomaly-induced symmetry breaking, in hadron formation. The proton's internal stress distribution has recently become measurable via extraction from gravitational form factors of the energy-momentum tensor, directly characterizing the confining forces and offering a new perspective. In this talk, I will present nucleon gravitational form factors and stress distributions within an extended Skyrme model that faithfully incorporates both chiral and scale symmetries. I will focus on how the scale anomaly shapes the nucleon's pressure distribution and on its essential role in ensuring nucleon stability.
