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Article
Report number	hep-th/9409141 ; CERN-TH-7425-94 ; SWAT-93-94-39 ; CERN-TH-7425-94 ; SWAT-39
Title	The exact mass-gap of the supersymmetric O(N) sigma model
Author(s)	Evans, Jonathan M. (CERN) ; Hollowood, Timothy J. (CERN)
Affiliation	(CERN)
Publication	1995
Imprint	23 Sep 1994
Number of pages	11
In:	Phys. Lett. B 343 (1995) 189-197
DOI	10.1016/0370-2693(94)01477-T
Subject category	General Theoretical Physics
Abstract	A formula for the mass-gap of the supersymmetric O($N$) sigma model ($N>4$) in two dimensions is derived: $m/\Lambda_{\overline{\rm MS}}=2 {2\Delta}\sin(\pi\Delta)/(\pi\Delta)$, where $\Delta=1/(N-2)$ 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.
Copyright/License	Copyright @ unknown. Published by Elsevier B.V.

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Email contact: [email protected] (Timothy Hollowood)