Symmetry energy in holographic QCD
Abstract
We study the symmetry energy (SE), an important quantity in nuclear physics, in the WittenSakaiSugimoto model and in a much simpler hardwall model of holographic QCD. The SE is the energy contribution to the nucleus due to having an unequal number of neutrons and protons. Using a homogeneous Ansatz representing smeared instantons and quantizing their isospin, we extract the SE and the proton fraction assuming charge neutrality and betaequilibrium, using quantization of the isospin zeromode. We also show the equivalence between our method adapted from solitons and the usual way of the isospin controlled by a chemical potential at the holographic boundary. We find that the SE can be well described in the WSS model if we allow for a larger 't Hooft coupling and lower KaluzaKlein scale than is normally used in phenomenological fits.
 Publication:

SciPost Physics
 Pub Date:
 June 2024
 DOI:
 10.21468/SciPostPhys.16.6.156
 arXiv:
 arXiv:2209.14309
 Bibcode:
 2024ScPP...16..156B
 Keywords:

 High Energy Physics  Phenomenology;
 High Energy Physics  Theory;
 Nuclear Theory
 EPrint:
 LaTeX: 29 pages, 5 figures