Massive ghost theories with a line of defects

TL;DR

This paper investigates free massive fermionic ghost theories with line defects, revealing resonance phenomena, instabilities, and a defect-dependent critical exponent through exact correlation function calculations.

Contribution

It introduces two types of defect interactions in massive ghost theories and computes exact correlation functions, highlighting novel resonance and critical behavior features.

Findings

Resonances and instabilities in relevant defect interactions.

Poles with imaginary residues in marginal defect cases.

Continuously varying critical exponent in the disorder operator.

Abstract

We study free massive fermionic ghosts, in the presence of an extended line of impurities, relying on the Lagrangian formalism. We propose two distinct defect interactions, respectively, of relevant and marginal nature. The corresponding scattering theories reveal the occurrence of resonances and instabilities in the former case and the presence of poles with imaginary residues in the latter. Correlation functions of the thermal and disorder operators are computed exactly, exploiting the bulk form factors and the matrix elements relative to the defect operator. In the marginal situation, the one-point function of the disorder operator displays a critical exponent continuously varying with the interaction strength.