The Higgs boson decay into ZZ decaying to identical fermion pairs

In order to investigate various decay channels of the Higgs boson [Formula: see text] or the hypothetical dilaton, we consider a neutral particle [Formula: see text] with zero spin and arbitrary [Formula: see text] parity. This particle can decay into two off-mass-shell [Formula: see text] bosons ([Formula: see text] and [Formula: see text]) decaying to identical fermion–antifermion pairs ([Formula: see text]): [Formula: see text]. We derive analytical formulas for the fully differential width of this decay and for the fully differential width of [Formula: see text] ([Formula: see text] stands for [Formula: see text], [Formula: see text], or [Formula: see text]). Integration of these formulas yields some Standard Model histogram distributions of the decay [Formula: see text] which are compared with corresponding Monte Carlo simulated distributions obtained by ATLAS and with ATLAS experimental data.

NEW TECHNIQUES IN THE SEARCH FOR Z′ BOSONS AND OTHER NEUTRAL RESONANCES

The search for neutral resonances at the energy frontier has a long and illustrious history, resulting in multiple discoveries. The canonical search scans the reconstructed invariant mass distribution of identified fermion pairs. Two recent analyses from the CDF experiment at the Fermilab Tevatron have applied novel methods to resonance searches. One analysis uses simulated templates to fit the inverse mass distribution of muon pairs, a quantity with approximately constant resolution for momenta measured with a tracking detector. The other analysis measures the angular distribution of electron pairs as a function of dielectron mass, gaining sensitivity over a probe of the mass spectrum alone. After reviewing several models that predict new neutral resonances, we discuss these CDF analyses and potential future applications.