Reconstructing the invariant mass of spin-2 particles decaying into diphoton in association with a dijet

Abstract

The Standard Model (SM) of particle physics, though highly successful, fails to incorporate gravity, which is hypothesized to be mediated by a spin-2 particle known as the graviton. This study explores the production and decay of a hypothesized generic massive spin-2 particle, Y₂, following a model proposed by Das and co-workers [Phys. Lett. B 770, 507 (2017)]. We focus on the pp → Y₂ + jj channel, where Y₂ decays into a diphoton pair. Event generation is performed using MadGraph5_aMC@NLO, interfaced with Pythia 8.307, which is followed by analysis and visualization via Rivet 3.1.7. The isolation algorithm for photons effectively "cleans" the signal, yielding clear reconstructed mass peaks for Y₂. We analyzed the reconstructed mass and the azimuthal angle between the diphotons for various Y₂ mass values. Our results show a high distribution of final state diphotons having an azimuthal separation of 2 to 3.1 radians, indicating a near-antiparallel direction of the decay products in the transverse plane of the collider. Signal-background comparisons demonstrate that the chosen background has a significantly lower cross-section after the algorithm was employed, thus, it is not a dominant background for the process. This work allows for further studies on more general backgrounds, enhancing the search for spin-2 particles in high-energy collisions.