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arXiv · 1204.1061

Diphotons from Tetraphotons in the Decay of a 125 GeV Higgs at the LHC

Patrick Draper·David McKeen
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Abstract

Recently the ATLAS and CMS experiments have presented data hinting at the presence of a Higgs boson at $m_h\simeq125$ GeV. The best-fit $h\rightarrowγγ$ rate averaged over the two experiments is approximately $2.1\pm0.5$ times the Standard Model prediction. We study the possibility that the excess relative to the Standard Model is due to $h\rightarrow aa$ decays, where $a$ is a light pseudoscalar that decays predominantly into $γγ$. Although this process yields $4γ$ final states, if the pseudoscalar has a mass of the order tens of MeV, the two photons from each $a$ decay can be so highly collimated that they may be identified as a single photon. Some fraction of the events then contribute to an effective $h\rightarrowγγ$ signal. We study the constraints on the parameter space where the net $h\rightarrowγγ$ rate is enhanced over the Standard Model by this mechanism and describe some simple models that give rise to the pseudoscalar-photon interaction. Further tests and prospects for searches in the near future are discussed.

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Patrick Draper, David McKeen. 2012-06-29. Diphotons from Tetraphotons in the Decay of a 125 GeV Higgs at the LHC. https://doi.org/10.1103/physrevd.85.115023

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