Abstract
The small background and the sensitivity to charged particles via a leading order loop coupling make the diphoton channel a privileged experimental test for new physics models. We propose a simple archetypal scenario to generate a sharp di-photon resonance as a result of threshold enhancements in the effective coupling between a heavy pseudoscalar particle and new vector-like leptons. We therefore study three different scenarios consistent with the current experimental limits and deviating from the Standard Model at the 2 σ level. The model also introduces a natural dark matter candidate able to match the observed dark matter abundance and comfortably respect the current direct detection constraints.
Highlights
Last year both the ATLAS and CMS experiments of the Large Hadron Collider (LHC) at CERN reported the presence of an excess in the diphoton channel, peaked at a centre-of-mass energy of about 750 GeV [1, 2]
For a lightest VL neutrino with mass mN1, whose value for each scenario is given in Table 5, we find the value of the physical coupling to A, yN1, reproducing the dark matter (DM) relic abundance as measured by the Planck collaboration, ΩDMh2 = 0.1188 ± 0.0010 [38]
While the preliminary evidence for the 750 GeV excess at the LHC has not be confirmed by the latest results that both ATLAS and CMS experiments presented at ICHEP 2016, the small background of the diphoton channel and its sensitivity to new physics via its leading order loop coupling make it a privileged experimental test for new physics
Summary
Last year both the ATLAS and CMS experiments of the Large Hadron Collider (LHC) at CERN reported the presence of an excess in the diphoton channel, peaked at a centre-of-mass energy of about 750 GeV [1, 2]. In the remaining of the paper we assume that the speculated particle has spin zero and investigate a way to produce a signal large enough for the corresponding resonance to be possibly discoverable in a dataset of the order of hundreds of fb−1,2 but still consistent with the current experimental limits. As it was the case for the 750 GeV excess, we require the absence of indications in complementary channels such as the di-jet, the tt, the di-boson and the di-lepton ones.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
