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arXiv · 1512.08777

A Megaxion at 750 GeV as a First Hint of Low Scale String Theory

Luis E. Ibanez·Victor Martin-Lozano
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Abstract

Low scale string models naturally have axion-like pseudoscalars which couple directly to gluons and photons (but not $W$s) at tree level. We show how they typically get tree level masses in the presence of closed string fluxes, consistent with the axion discrete gauge symmetry, in a way akin of the axion monodromy of string inflation and relaxion models. We discuss the possibility that the hints for a resonance at 750 GeV recently reported at ATLAS and CMS could correspond to such a heavy axion state (megaxion). Adjusting the production rate and branching ratios suggests the string scale to be of order $M_s$ ~ $7 - 10^4$ TeV, depending on the compactification geometry. If this interpretation was correct, one extra $Z'$ gauge boson could be produced before reaching the string threshold at LHC and future colliders.

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Luis E. Ibanez, Victor Martin-Lozano. 2015-12-29. A Megaxion at 750 GeV as a First Hint of Low Scale String Theory. https://doi.org/10.1007/jhep07(2016)021

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