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arXiv · hep-th/9409141

The Exact Mass-Gap of the Supersymmetric O(N) Sigma Model

Jonathan M. Evans·Timothy J. Hollowood
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Abstract

A formula for the mass-gap of the supersymmetric O($N$) sigma model ($N>4$) in two dimensions is derived: $m/Λ_{\overline{\rm MS}}=2^{2Δ}\sin(πΔ)/(πΔ)$, where $Δ=1/(N-2)$ and $m$ is the mass of the fundamental vector particle in the theory. This result is obtained by comparing two expressions for the free-energy density in the presence of a coupling to a conserved charge; one expression is computed from the exact S-matrix of Shankar and Witten via the the thermodynamic Bethe ansatz and the other is computed using conventional perturbation theory. These calculations provide a stringent test of the S-matrix, showing that it correctly reproduces the universal part of the beta-function and resolving the problem of CDD ambiguities.

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Jonathan M. Evans, Timothy J. Hollowood. 1994-09-23. The Exact Mass-Gap of the Supersymmetric O(N) Sigma Model. https://doi.org/10.1016/0370-2693(94)01477-t

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