Improved BFT quantization of O(3) nonlinear sigma model

TL;DR

This paper applies an improved BFT Hamiltonian method to the O(3) nonlinear sigma model, deriving a BRST invariant Lagrangian and analyzing soliton zero modes, advancing the quantization approach for this model.

Contribution

It introduces an improved BFT Hamiltonian approach to the O(3) nonlinear sigma model, deriving a compact first class Hamiltonian and BRST invariant Lagrangian.

Findings

Zero mode spectrum remains unchanged after BFT procedure

Derived a compact form of the nontrivial first class Hamiltonian

Established a semi-classical quantization framework for solitons

Abstract

We newly apply the improved Batalin-Fradkin-Tyutin(BFT) Hamiltonian method to the O(3) nonlinear sigma model, and directly obtain the compact form of nontrivial first class Hamiltonian by introducing the BFT physical fields. Furthermore, following the BFV formalism, we derive the BRST invariant gauge fixed Lagrangian through the standard path-integral procedure. Finally, by introducing collective coordinates, we also study a semi-classical quantization of soliton background to conclude that the spectrum of zero modes are unchanged through the BFT procedure.