Deep Inelastic Scattering in Holographic AdS/QCD Models

2020

We study deep inelastic scattering (DIS) of charged leptons from polarised spin-1/2 hadrons in terms of the gauge/gravity duality. We calculate the structure functions related to spin-1/2 fermionic operators of N = 4 SYM theory in the planar limit and at strong coupling. Specifically, we focus on the twist-3 operator which is dual to a certain dilatino mode and gives the leading contribution to the hadronic tensor. We consider the Bjorken variable within the parametric range λ −1/2 SYM ≪ x < 1 where the supergravity dual description holds. From dimensional reduction of type IIB supergravity on the five-sphere, we derive the interaction terms involving two dilatini and a massless vector field mode. This vector field is a linear combination of certain components of the graviton and the four-form potential. The angular integrals on the five-sphere lead to selection rules for the interactions with important consequences on the dynamics. This implies the existence of new terms contributing to the structure functions that we explicitly calculate. The leading contribution comes from the Pauli term, followed by the contributions from the new terms we found.

Section: Jhep06(2020)063mentioning

confidence: 99%

Spin-1/2 fermionic operators of $$ \mathcal{N} $$ = 4 SYM theory and DIS from type IIB supergravity

Jorrin

Michalski

2020

“…Further developments including the eikonal approach, have been presented in [30,31,32,33,34,35,36,37,38,39]. Other aspects of applications of the AdS/CFT correspondence to DIS processes can be found in [40,41,42,43,44,45].…”

Section: Figurementioning

confidence: 99%

Deep inelastic scattering from polarized spin-1/2 hadrons at low x from string theory

Kovensky

Michalski

2018

We study polarized deep inelastic scattering of charged leptons from spin-1/2 hadrons at low values of the Bjorken parameter and large 't Hooft coupling in terms of the gauge/string theory duality. We calculate the structure functions from type IIB superstring theory scattering amplitudes. We discuss the role of the non-Abelian Chern-Simons term and the Pauli term from the five-dimensional SU(4) gauged supergravity. Furthermore, the exponentially small-x regime where Regge physics becomes important is analyzed in detail for the antisymmetric structure functions. In this case the holographic dual picture of the Pomeron exchange is realized by a Reggeized gauge field. We compare our results with experimental data of the proton antisymmetric structure function g 1 , obtaining a very good level of agreement.

Towards 1/N corrections to deep inelastic scattering from the gauge/gravity duality

Jorrin

Kovensky

2016

1/N 2 corrections to deep inelastic scattering (DIS) of charged leptons from glueballs at strong coupling are investigated in the framework of the gauge/gravity duality. The structure functions F 1 and F 2 (and also F L ) are studied at subleading order in the 1/N 2 expansion, in terms of q 2 and the Bjorken parameter x. The relevant type IIB supergravity one-loop diagrams (which correspond to DIS with two-hadron final states) are studied in detail, while n-loop diagrams (corresponding to DIS with (n + 1)-hadron final states) are briefly discussed. The 1/N 2n and Λ 2 /q 2 dependence of the structure functions is analyzed. Within this context two very different limits are considered: one is the large N limit and the other one is when the virtual photon momentum transfer q is much larger than the infrared confining scale Λ. These limits do not commute.