# 26th International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY2018)

23-27 July 2018
Barcelona
Europe/Zurich timezone

## Dissecting Multi-Photon Resonances at the Large Hadron Collider

25 Jul 2018, 18:20
20m
Plaza 1

Talk (closed)

### Speaker

Dr Abhishek Iyer (INFN)

### Description

We examine the phenomenology of the production, at the 13 TeV Large Hadron
Collider (LHC), of a heavy resonance $X$, which decays via other new on-shell particles $n$ into multi- (i.e.\ three or more) photon final states. In the limit that $n$ has a much smaller mass than $X$, the multi-photon final state may dominantly appear as a two-photon final state because the $\gamma$s from the $n$ decay are highly collinear and remain unresolved. We discuss how to discriminate this scenario from $X \rightarrow \gamma \gamma$: rather than discarding non-isolated photons, it is better instead to relax the isolation criterion and instead form photon jet substructure variables. The spins of $X$ and $n$ leave their imprint upon the distribution of pseudorapidity gap $\Delta \eta$ between the apparent two-photon states. Depending on the total integrated luminosity, this can be used in many cases to claim discrimination between the possible spin choices of $X$ and $n$, although the case where $X$ and $n$ are both scalar particles cannot be discriminated from the direct $X \rightarrow \gamma \gamma$ decay in this manner. Information on the mass of $n$ can be gained by considering the mass of each photon jet.

Parallel Session Alternatives to Supersymmetry

### Primary author

Dr Abhishek Iyer (INFN)

### Co-authors

Prof. Benjamin Allanach (University of Cambridge (GB)) Disha Bhatia (TIFR)