Gauge/Gravity Duality and Hadron Physics at the Light-Front

Understand

We discuss some remarkable features of the light-front holographic mapping of classical gravity in anti-de Sitter space modified by a confining dilaton background.

• In particular, we show that a positive-sign dilaton solution $\exp(+\kappa^2 z^2)$ has better chances to describe the correct hadronic phenomenology than the negative solution $\exp{(- \kappa^2 z^2)}$ extensively studied in the literature.
• We also show that the use of twist-scaling dimensions, instead of canonical dimensions, is required to give a good description of the spectrum and form factors of hadrons.
• Another key element is the explicit connection of AdS modes of total angular momentum $J$ with the internal structure of hadrons and the proper identification of the orbital angular momentum of the constituents.