Propagating Torsion in 3D-Gravity and Dynamical Mass Generation

TL;DR

This paper investigates how dynamical torsion and gauge fields interact with fermions in 3D gravity, revealing a one-loop mass generation mechanism for gauge fields but not for fermions, which only experience a mass shift.

Contribution

It introduces a novel analysis of dynamical torsion and Kalb-Ramond fields coupled to fermions in 3D gravity, demonstrating specific mass generation mechanisms at one-loop level.

Findings

Mass generation for 2-form gauge field and torsion at 1-loop.

Fermions do not acquire mass dynamically, only a mass shift.

Gauge invariance is maintained in the non-minimal coupling.

Abstract

In this paper, fermions are minimally coupled to 3D-gravity where a dynamical torsion is introduced. A Kalb-Ramond field is non-minimally coupled to these fermions in a gauge-invariant way. We show that a 1-loop mass generation mechanism takes place for both the 2-form gauge field and the torsion. As for the fermions, no mass is dynamically generated: at 1-loop, there is only a mass shift proportional to the Yukawa coupling whenever the fermions have a non-vanishing tree-level mass.