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arXiv · 1602.06257

String Consistency, Heavy Exotics, and the 750 GeV Diphoton Excess at the LHC: Addendum

Mirjam Cvetic·James Halverson·Paul Langacker
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Abstract

We study models with heavy exotics that account for the LHC $750$ GeV diphoton excess in light of current vector-like quark bounds. Utilizing only exotics that may appear in three-stack and four-stack D-brane models, we show that a narrow width diphoton excess can be accounted for while evading existing bounds if multiple exotics are added, with vector-like leptons of mass $M_L\lesssim 375$ GeV and vector-like quarks with masses up to $\simeq 3$ TeV. However, a large width $(\Gamma/M \sim 0.06)$, as suggested by the ATLAS data, cannot be easily accommodated in this framework. Renormalization group equations with GUT-scale boundary conditions show that these supersymmetric models are perturbative and stable. Type IIA compactifications on toroidal orbifolds allow for $O(10)$ Yukawa couplings in the ultraviolet.

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Mirjam Cvetic, James Halverson, Paul Langacker. 2016-02-19. String Consistency, Heavy Exotics, and the 750 GeV Diphoton Excess at the LHC: Addendum. https://arxiv.org/abs/1602.06257

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