The strongly coupled $E_8\times E_8$ heterotic string: Geometry $\&$ Phenomenology

Abstract

Working within the context of the strongly coupled $E_8\times E_8$ heterotic string theory, we analyze the $B-L$ MSSM, a realistic supersymmetric extension of the Standard Model, from both a low-energy phenomenology and high-energy string perspective. From a formal point of view, we examine different constructions of string vacua, which satisfy a series of theoretical and phenomenological constraints. Such vacua configurations are anomaly-free, preserve $N = 1$ SUSY at the compactification scale and yield the correct value for the $SO(10)$ unification scale and gauge coupling in the visible particle sector. Furthermore, we analyze a possible SUSY-breaking mechanism for the type of vacua we construct, via gaugino condensation in the hidden sector. In an attempt to connect these findings to experiment, we study the prospects of detecting the $B-L$ MSSM at the LHC in the near future. Within this specific context, we show that R-parity violating decays of supersymmetric particles could be amenable to direct detection at the ATLAS and CMS detectors. Detection of these processes would not only be an explicit indication of "Beyond the Standard Model" physics, but would also hint strongly at the existence of $N=1$ SUSY with spontaneously broken R-parity.