Prospective Analysis Spin- and CP-sensitive Variables in H -> ZZ -> l_1 l_1 l_2 l_2 with Atlas
C. P. Buszello, I. Fleck, P. Marquard, J. J. van der Bij
TL;DR
The paper proposes using angular correlations in $H \\to ZZ \\to l_1^+ l_1^- l_2^+ l_2^-$ to determine the Higgs boson's spin and CP for $m_H>2m_W$, focusing on the clean four-lepton final state. It compares the SM Higgs $0^+$ angular distributions with those from hypothetical particles with different quantum numbers. The analysis relies on the complete triple differential cross-sections and angular observables; detector acceptance and efficiencies motivate a detector-level ATLAS study. Using ATLAS with fast detector simulation, the work suggests these angular correlations can be measured to verify the $0^+$ hypothesis and exclude $0^-$ and $1^+$ at an integrated luminosity of 100 fb$^{-1}$.
Abstract
A possibility to prove spin and CP-eigenvalue of a Standard Model (SM) Higgs boson is presented. We exploit angular correlations in the subsequent decay H -> ZZ -> 4l (muons or electrons) for Higgs masses above 200 GeV. We compare the angular distributions of the leptons originating from the SM Higgs with those resulting from decays of hypothetical particles with differing quantum numbers. We restrict our analysis to the use of the Atlas-detector which is one of two multi-purpose detectors at the upcoming 14 TeV proton-proton-collider (LHC) at CERN. By applying a fast simulation of the Atlas detector it can be shown that these correlations will be measured sufficiently well that consistency with the spin-CP hypothesis 0+ of the Standard Model can be verified and the 0- and 1+- can be ruled out with an integrated luminosity of 100 fb^-1.