Energy-Momentum Tensor and D-term of Baryons in Top-down Holographic QCD

Abstract

We study the energy-momentum tensor of a baryon in a top-down holographic QCD. In holographic QCD, the baryons are represented as solitons in a 5-dimensional gauge theory. We obtain the soliton solution by solving the equations of motion numerically. Using this result, the energy-momentum tensor and related quantities such as the mass, mean square radii, and the D-term (druck term) are computed. The evaluated D-term is about -2.05, whose absolute value is significantly larger than that in the previous work arXiv:2206.06578.

Figures (4)

• Figure 1: Energy density and Chern number density of the baryon on $r$ - $w$ plane. The plot range is restricted to $0\leq w\leq w_\mathrm{max}=\pi/2$, which corresponds to $0\leq z<+\infty$.
• Figure 2: Energy density and Chern number density along the $r$ direction. The black dashed line is $\mathrm{ch}_2(r,w)$ integrated along the $w$ axis. The blue solid line is $4\pi r^2\epsilon(r)$ normalized with $M_\mathrm{sol}$. The right figure is plotted in the log-scale. The red solid and dashed lines are $1/r^7$ and $1/r^4$, respectively.
• Figure 3: $p(r)$ and $s(r)$ multiplied with $4\pi r^2$. The blue solid line is $p(r)$ and the red dashed line is $s(r)$.
• Figure 4: $t$ dependence of $D(t)$. The graph is derived from \ref{['eq:D(t)-symmetric']} for $t\neq0$, and $D(0)$ is fixed to $D_s = -2.05$.