# Deep Inelastic Scattering on an Extremal RN-AdS Black Hole II: Holographic Fermi Surface

## TL;DR

This paper uses holographic duality to analyze deep inelastic scattering on a dense nucleus modeled as an extremal RN-AdS black hole, revealing emergent Fermi surfaces and anomalous partonic distributions at large-x.

## Contribution

It introduces a holographic model of DIS on dense nuclei with emergent Fermi surfaces, providing new insights into partonic distributions and scattering rules in strongly coupled regimes.

## Key findings

- Identification of emergent Fermi surface with anomalous dimensions near black hole horizon
- Modified hard scattering rules due to holographic effects
- Model's predictions agree with experimental data for various nuclei

## Abstract

We consider deep inelastic scattering (DIS) on a dense nucleus described as an extremal RN-AdS black hole with holographic quantum fermions in the bulk. We evaluate the 1-loop fermion contribution to the R-current on the charged black hole, and map it on scattering off a Fermi surface of a dense and large nucleus with fixed atomic number. Near the black hole horizon, the geometry is that of AdS$_2\times $R$^3$ where the fermions develop an emergent Fermi surface with anomalous dimensions. DIS scattering off these fermions yields to anomalous partonic distributions mostly at large-x, as well as modified hard scattering rules. The pertinent R-ratio for the black hole is discussed. For comparison, the structure functions and the R-ratio in the probe or dilute limit with no back-reaction on the geometry, are also derived. We formulate a hybrid holographic model for DIS scattering on heavy and light nuclei, which compares favorably to the existing data for Pb, Au, Fe, C and He over a wide range of parton-x.