Multiphotons and Photon-Jets

Abstract

We discuss an extension of the Standard Model with a new vector-boson decaying predominantly into a multi-photon final state through intermediate light degrees of freedom. The model has a distinctive phase in which the photons are collimated. As such, they would fail the isolation requirements of standard multi-photon searches, but group naturally into a novel object, the photon-jet. Once defined, the photon-jet object facilitates more inclusive searches for similar phenomena. We present a concrete model, discuss photon-jets more generally, and outline some strategies that may prove useful when searching for such objects.

Figures (2)

• Figure 1: The fraction of events with only one diphoton satisfying $\Delta R > \Delta R_{\rm min}$ for $M_{Z^\prime} = 1~\mathrm{TeV}$ and two choices of the scalar mass. The dashed lines represent the approximate formula, Eq. (\ref{['eqn:frac1']}) whereas the filled data points are from a monte-carlo simulation of the full event at the LHC with $\sqrt{s} = 7~\mathrm{TeV}$. The hollow data points are simulation including a transverse energy cut on the photons of $10~\mathrm{GeV}$.
• Figure 2: The fraction of events with two diphotons both satisfying $\Delta R > \Delta R_{\rm min}$ for the same choice of parameters as in Fig. \ref{['fig:frac1']}. We note the expected deterioration of the approximation, Eq. (\ref{['eqn:frac2']}), as $\Delta R_{\rm min}$ diminishes as well as when the scalar mass increases resulting in a smaller boost. The loss of accuracy at higher $\Delta R_{\rm min}$ is only due to limited statistics.