Higher-twist fermionic operators and DIS structure functions from the AdS/CFT duality

TL;DR

This paper explores how higher-twist fermionic operators influence deep inelastic scattering structure functions in strongly coupled ${ m N}=4$ SYM theory using AdS/CFT duality, revealing new effects beyond minimal twist contributions.

Contribution

It explicitly computes structure functions for higher-twist fermionic operators in various $SU(4)_R$ representations within the AdS/CFT framework, extending previous minimal twist analyses.

Findings

New effects identified in higher-twist contributions to structure functions.

Explicit calculations for operators in 20* and 60* representations.

Comparison with minimal twist case highlights significant differences.

Abstract

The role of local higher-twist ($\tau > 3$) spin-1/2 fermionic operators of the strongly coupled ${\cal {N}}=4$ supersymmetric Yang-Mills theory on the symmetric and antisymmetric deep inelastic scattering (DIS) structure functions is investigated. The calculations are carried out in terms of the duality between ${\cal {N}}=4$ SYM theory and type IIB supergravity on AdS$_5 \times S^5$. Particularly, we explicitly obtain the structure functions for single-trace spin-1/2 fermionic operators in the 20$^*$ and 60$^*$ irreducible representations of $SU(4)_R$, corresponding to twists 4 and 5, respectively. We also calculate the contributions of other single-trace spin-1/2 fermionic operators in the 4, 20 and 60 irreducible representations of $SU(4)_R$. New important effects are found in comparison with the minimal twist ($\tau = 3$) case, and they are studied thoroughly.