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Slightly broken higher-spin current in bosonic and fermionic QED in the large-$N$ limit

by Zheng Zhou, Yin-Chen He

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Submission summary

Authors (as registered SciPost users): Zheng Zhou
Submission information
Preprint Link: https://arxiv.org/abs/2205.07897v2  (pdf)
Date accepted: 2023-07-10
Date submitted: 2023-06-01 03:02
Submitted by: Zhou, Zheng
Submitted to: SciPost Physics
Ontological classification
Academic field: Physics
Specialties:
  • Condensed Matter Physics - Theory
Approach: Theoretical

Abstract

We study the slightly broken higher-spin currents in various CFTs with $\mathrm{U}(1)$ gauge field, including the tricritical QED, scalar QED, fermionic QED and QED-Gross-Neveu-Yukawa theory. We calculate their anomalous dimension by making use of the classical non-conservation equation and the equations of motion. We find a logarithmic asymptotic behaviour ($\gamma_s\sim 16/(N\pi^2) \log s $) of the anomalous dimension at large spin $s$, which is different from other interacting CFTs without gauge fields and may indicate certain unique features of gauge theories. We also study slightly broken higher-spin currents of the $\mathrm{SU}(N)_1$ WZW model at $d=2+\epsilon$ dimensions by formulating them as the QED theory, and we again find its anomalous dimension has a logarithmic asymptotic behaviour with respect to spin. This result resolves the mystery regarding the mechanism of breaking higher spin currents of Virasoro symmetry at $d=2+\epsilon$ dimensions, and may be applicable to other interesting problems such as the $2+\epsilon$ expansion of Ising CFT.

Author comments upon resubmission

We are thankful to both Referees for carefully reviewing the paper and providing useful comments and suggestions, which helped us to improve the manuscript.

We appreciate the positive evaluation of both Referees. We also thank their critical comments that are important to understanding the problems in concern. These points are addressed in the attached reply. Thanks to the comments of the Referees, we have made improvements to the paper. The revisions made are listed below.

We give a point-by-point response to the comments of all Referees. We hope that with the changes made, the current manuscript will be considered suitable for further consideration in SciPost Physics.

List of changes

* We have added discussion on the simultaneous limits that we take for $s$ and $N$ in Section 6;

* We have added discussion to clarify the absence of divergence operator in 2d and its reappearance in $(2+\epsilon)$d in Section 5;

* We have added relevant references for lightcone bootstrap mentioned by Referee 1;

* We have corrected several typos mentioned by Referee 2;

* We have added discussion to clarify the generalisation of $\mathrm{SU}(N)_1$ WZW from 2d to $(2+\epsilon)$d in Section 5.

Published as SciPost Phys. 15, 072 (2023)

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