Gravitational form factors and mechanical properties of the proton

초록

The gravitational form factors of the proton provide essential information on its mechanical structure such as its mass, spin, mechanical pressure, and shear force. In the current talk, we present recent results for the flavor decomposition of the gravitational form factors (GFFs) of the proton in a pion mean-field approach or the chiral quark-soliton model, which illuminate the distinctive role played by the separate quarks. We assess the quantitative fraction of light-front momentum carried by individual quark flavors within the nucleon. We analyze variations arising from the flavor decomposition of the mass distribution, as evidenced through the non-conserved ?c(q 2 ) form factor of the nucleon, which is also known as the proton cosmological term. We study not only the decomposition of the total angular momentum into the orbital angular momentum and intrinsic spin, but also its flavor decomposition. We then examine the intricate interplay between the D-term and ?c form factors and their collaborative impact on the stabilization of the nucleon system. Questioning the assumption of “large Nc blindness” concerning D u?d ∼ 0 in a recent experimental analysis, we compute it within both the flavor SU(2) and SU(3) framework. We conclude that such an assumption finds justification predominantly within the framework of flavor SU(3) symmetry.