Enhanced gauge symmetry and winding modes in Double Field Theory

C. NUÑEZ; M. MAYO; G. ALDAZABAL; J. A. ROSABAL

JOURNAL OF HIGH ENERGY PHYSICS

SPRINGER

Lugar: Berlin; Año: 2016 p. 1 - 34

1126-6708

Abstract: We provide an explicit example of how the string winding modes can be incorporated in double field theory. Our guiding case is the closed bosonic string compactified on a circle of radius close to the self-dual point, where some modes with non-zero windingor discrete momentum number become massless and enhance the U(1) × U(1) symmetry to SU(2) × SU(2). We compute three-point string scattering amplitudes of massless and slightly massive states, and extract the corresponding effective low energy gauge field theory. The enhanced gauge symmetry at the self-dual point and the Higgs-like mechanism arising when changing the compactification radius are examined in detail. The extra massless fields associated to the enhancement are incorporated into a generalized frame with O(d+3,d+3) structure, where d is the number of non-compact dimensions. We devise a O(d+3)×O(d+3)consistent double field theory action that reproduces the low energy string effective actionwith enhanced gauge symmetry. The construction requires a truly non-geometric frame which explicitly depends on both the compact coordinate along the circle and its dual.