Threshold corrections in orbifold models and superstring unification of gauge interactions

Journal Article · Mon Apr 01 04:00:00 EST 1996 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.53.3920· OSTI ID:279853

Chemtob, M ^[1]

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1. Service de Physique Theorique, CE-Saclay F-91191 Gif-sur-Yvette, Cedex (France)

The string one loop renormalization of the gauge coupling constants is examined in Abelian orbifold models. The contributions to string threshold corrections independent of the compactification moduli fields are evaluated numerically for several representative examples of orbifold models. We consider cases with standard and nonstandard embeddings as well as cases with discrete Wilson line background fields which match reasonably well with low energy phenomenology. The gap separating the observed grand unification scale {ital M}{sub GUT}{approx_equal}2{times}10{sup 16} GeV from the string unification scale {ital M}{sub {ital X}}{approx_equal}5{times}10{sup 17} GeV is discussed on the basis of standardlike orbifold models. We examine one loop gauge coupling constant unification in a description incorporating the combined effects of moduli-dependent and -independent threshold corrections, an adjustable affine level for the hypercharge group factor, and a large mass threshold associated with an anomalous U(1) mechanism. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 279853
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 7 Vol. 53; ISSN 0556-2821; ISSN PRVDAQ
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
COMPACTIFICATION
CORRECTIONS
COUPLING CONSTANTS
HYPERCHARGE
NUMERICAL ANALYSIS
SUPERSTRING MODELS
U-1 GROUPS