Non-tachyonic ground state for string theory

Abstract

Starting from the basic open-string Lagrangian system, we apply the methods of the operator field to the center-of-mass coordinateX0. In this way, we arrive at a quantization of the open string for which the following results hold: 1) The ground state of the open string has energy 0 in the standard conventions of the method of the operator field. 2) There is no tachyon in the physical spectrum of the theory. 3) The lowest single-particle states correspond to a massless-vector state at leveln = 1 and a massive spin-2 particle of massM = 2MPlanck at leveln = 2.