Landscape of Simple Superconformal Field Theories in 4d
Kazunobu Maruyoshi, Emily Nardoni, Jaewon Song
TL;DR
This work maps a landscape of simple four-dimensional ${\mathcal{N}}=1$ SCFTs generated from ${SU(2)}$ gauge theory with one adjoint and two fundamentals by exhaustively exploring relevant deformations, including gauge-singlet couplings. Using ${a}$-maximization and the superconformal index as primary viability tests, the authors identify ${34}$ good fixed points—among them two enhanced ${\mathcal{N}}=2$ Argyres–Douglas theories ${H_0}$ and ${H_1}$ and a minimal ${\mathcal{N}}=1$ theory ${H_0^*}$—as well as ${36}$ questionable fixed points with potential accidental symmetries and unphysical operators, notably a candidate minimal theory ${\mathcal{T}}_M$ with very small ${a}$ and ${c}$. The good theories exhibit emergent symmetry and operator decoupling, and their ${a}$ and ${c}$ values lie in a narrow band with ${a}/{c}\approx 0.87$, while the bad set hints at further structure (e.g., decoupled fermions) needed to resolve unitarity concerns. Overall, the paper provides a practical framework for enumerating and testing simple ${\mathcal{N}}=1$ SCFTs via Lagrangian RG flows, highlighting near-minimal theories and raising questions about IR accidental symmetries and the true minimal fixed point in this landscape.
Abstract
We explore the space of renormalization group flows that originate from $\mathcal{N}=1$ supersymmetric $SU(2)$ gauge theory with one adjoint and a pair of fundamental chiral multiplets. By considering all possible relevant deformations - including coupling to gauge-singlet chiral multiplets - we find 34 fixed points in this simple setup. We observe that theories in this class exhibit many novel phenomena: emergent symmetry, decoupling of operators, and narrow distribution of central charges $a/c$. This set of theories includes two of the $\mathcal{N}=2$ minimal Argyres-Douglas theories and their mass deformed versions. In addition, we find 36 candidate fixed point theories possessing unphysical fermionic operators -including one with central charges $(a, c)\simeq (0.20, 0.22)$ that are smaller than any known superconformal theory -that need further investigation.
