Study of the Spin-Parity of a Resonance via the Gold-Plated Decay Mode

Abstract

The Higgs is the most significant discovery in the first LHC run. As a discovery machine the LHC or new colliders such as the ILC may also observe new resonances in the future. After the discovery of a new resonance, a detailed phenomenological study of its decay products will enable us to infer its spin, parity and charge conjugation. If a resonance (X) is seen in the experimentally clean four lepton decay channel via two intermediate Z bosons, the resonance could be a scalar or a vector boson or a higher spin particle. Four lepton final state will allow us to fully reconstruct the four momenta of X and hence one can find out different kinematic variables and angular distributions to disentangle the spin and parity of it. In our work we show how one can obtain three uniangular distributions using these kinematic variables and finally construct several angular asymmetries to determine the spin parity and the couplings of the resonance X to the Z bosons.