1993/03/11 by Luis E. Ibáñez, Luis E. Ibanez, Ibanez, Luis E.
Computer Science · Physics and Astronomy · #Computational Physics and Python Applications #Cosmology and Gravitation Theories #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #Particle physics theoretical and experimental studies #hep-ph #hep-th
paper · pdf · doi:10.48550/arxiv.hep-ph/9303244
12 pages, FTUAM-93-08, harvmac
arxiv created 1993/03/11 · openalex publication_date 1993/03/11 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Four-dimensional strings with the standard model gauge group SU(3)× SU(2)× U(1) give model-dependent predictions for the tree level weak mixing-angle. In the presence of an extra pseudo-anomalous gauged- U(1)X, the value of the weak angle may be computed purely in terms of the charges of the massless fermions of the theory, independently of the details of the massive string sector. I present the simplest such U(1)X which leads to the canonical result sin2θW=3/8 in the supersymmetric standard model. This is a sort of gauged Peccei-Quinn symmetry which requires the presence of just the minimal set of Higgs doublets and forbids dimension-four B and L-violating terms. In this approach the cancellation of the U(1)X anomalies through a Green-Schwarz mechanism plays a crucial role. In a different context (that of non-string low-energy supersymmetric models) I briefly discuss wether this type of anomaly cancellation mechanism could be of phenomenological relevance close to the electroweak scale. (Talk at the 23-th Workshop of the INFN Eloisatron Project on Properties of Susy particles, Erice, October 1992)