Alfaro, J.Dobado González, AntonioEspriu, Domènec2023-06-202023-06-201999-08-120370-269310.1016/S0370-2693(99)00809-6https://hdl.handle.net/20.500.14352/58724© 1999 Published by Elsevier Science B.V. All rights reserved. We thank A. Andrianov for multiple discussions. This work was initiated during the visit of one of the authors to the Departamento de Física of the Universidad Católica de Chile, whose hospitality is gratefully acknowledged. We acknowledge the financial support from grants CICYT AEN98-0431 and AEN96-1634, CIRIT 1996SGR00066, and, specially, from the ‘Programa de Cooperación con Iberoamérica’. J.A. is partially supported by the project Fondecyt 1980816.We propose a method to derive the low-energy effective action of QCD assuming that the long-distance properties of strong interactions can be described by a string theory. We bypass the usual problems related to the existence of the tachyon and absence of the adequate Adler zero by using a sigma model approach where excitations above the correct (chirally non-invariant) QCD vacuum are included. Two-dimensional conformal invariance then implies the vanishing of the O(p(4)) effective lagrangian coefficients. We interpret this result and discuss ways to go beyond this limit.engjournal articlehttp://dx.doi.org/10.1016/S0370-2693(99)00809-6http://www.sciencedirect.comhttp://arxiv.org/abs/hep-th/9901074open access53ModelsSupergravityFieldsFísica (Física)22 Física