Making ends meet: String unification and low-energy data

Keith R. Dienes, Alon E. Faraggi

Research output: Contribution to journalArticlepeer-review

71 Scopus citations


We examine the effects that may resolve the disagreement between string-scale unification and low-energy data. These include string threshold corrections, nonstandard hypercharge normalizations, light supersymmetric thresholds, intermediate gauge structure, and extra matter beyond the minimal supersymmetric standard model. We explicitly evaluate these effects within the flipped SU(5), SO(6)×SO(4), and various SU(3)×SU(2)×U(1) string models, and surprisingly find that the only way to reconcile string unification with low-energy data is through certain types of extra matter. Remarkably, many of the realistic string models contain precisely this required matter in their massless spectra.

Original languageEnglish (US)
Pages (from-to)2646-2649
Number of pages4
JournalPhysical review letters
Issue number14
StatePublished - 1995

ASJC Scopus subject areas

  • General Physics and Astronomy


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