Towards a Bootstrap approach to higher orders of epsilon expansion

TL;DR

This paper develops a hybrid bootstrap method to compute higher-order epsilon expansion data for higher spin operators in Wilson-Fisher and $ ext{phi}^3$ theories, providing new predictions and cross-checks.

Contribution

It introduces a novel hybrid bootstrap approach combining Mellin space and Feynman diagram techniques for higher order epsilon expansions.

Findings

New predictions at $O()$ and $O()$ for anomalous dimensions and OPE coefficients.

Cross-validation of Mellin Bootstrap results with traditional methods.

Demonstration of higher loop order calculations using the bootstrap in Mellin space.

Abstract

We employ a hybrid approach in determining the anomalous dimension and OPE coefficient of higher spin operators in the Wilson-Fisher theory. First we do a large spin analysis for CFT data where we use results obtained from the usual and the Mellin Bootstrap and also from Feynman diagram literature. This gives new predictions at $O(\epsilon^4)$ and $O(\epsilon^5)$ for anomalous dimensions and OPE coefficients, and also provides a cross-check for the results from Mellin Bootstrap. These higher orders get contributions from all higher spin operators in the crossed channel. We also use the Bootstrap in Mellin space method for $\phi^3$ in $d=6-\epsilon$ CFT where we calculate general higher spin OPE data. We demonstrate a higher loop order calculation in this approach by summing over contributions from higher spin operators of the crossed channel in the same spirit as before.