The anomalous U(1)anom symmetry and flavors from an SU(5) x SU(5)′ GUT in Z 12−I orbifold compactification

Abstract

In string compactifications, frequently the anomalous U(1) gauge symmetry appears which belongs to E 8 ×E ′ 8 E8×E8′ of the heterotic string. This anomalous U(1) gauge boson obtains mass at the compactification scale (≈10 18 GeV ≈1018GeV) by absorbing one pseudoscalar (corresponding to the model-independent axion) from the second rank antisymmetric tensor field B MN BMN . Below the compactification scale a global symmetry U(1) anom U(1)anom results whose charge Q anom Qanom is the original gauge U(1) charge. This is the most natural global symmetry, realizing the “invisible” axion. This global symmetry U(1) anom U(1)anom is suitable for a flavor symmetry. In the simplest compactification model with the flipped SU(5) grand unification, all the low energy parameters are calculated in terms of the vacuum expectation values of the standard model singlets. © The Author(s) 2017. This article is an open access publication