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arXiv · hep-th/9612066

"Anomalous" U(1) Symmetry in Orbifold String Models

Tatsuo Kobayashi·Hiroaki Nakano
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Abstract

``Anomalous'' U(1) gauge symmetry with Green-Schwarz anomaly cancellation mechanism is discussed in the orbifold construction of four-dimensional heterotic string models. Some conditions are given as criteria to have ``anomalous'' U(1) in orbifold string models. In particular, ``anomalous'' U(1) is absent if the massless twisted matter has no mixing between visible and hidden sectors or if a certain type of discrete symmetries are found. We then give a general procedure for classifying orbifold models with ``anomalous'' U(1) and for identifying the ``anomalous'' U(1) basis. We illustrate our procedure in Z_3 and Z_4 orbifold models. According to our procedure, the classification of ``anomalous'' U(1) can be reduced to the classification in the absence of a Wilson line. We also discuss discrete symmetries left unbroken after the ``anomalous'' U(1) breaking. This includes a possible relation between ``anomalous'' U(1) and discrete R-symmetries.

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Tatsuo Kobayashi, Hiroaki Nakano. 1996-12-06. "Anomalous" U(1) Symmetry in Orbifold String Models. https://doi.org/10.1016/s0550-3213(97)00210-1

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