Spin and parity of a single-produced resonance at the LHC

By S. Bolognesi, Yanyan Gao, A. Gritsan, K. Melnikov, M. Schulze, Nhan Tran, A. Whitbeck. 2012

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The experimental determination of the properties of the newly discovered boson at the Large Hadron Collider is currently the most crucial task in high energy physics. We show how information about the spin, parity, and, more generally, the tensor structure of the boson couplings can be obtained by studying angular and mass distributions of events in which the resonance decays to pairs of gauge bosons, $ZZ, WW$, and $\gamma \gamma$. A complete Monte Carlo simulation of the process $pp \to X \to VV \to 4f$ is performed and verified by comparing it to an analytic calculation of the decay amplitudes $X \to VV \to 4f$. Our studies account for all spin correlations and include general couplings of a spin $J=0,1,2$ resonance to Standard Model particles. We also discuss how to use angular and mass distributions of the resonance decay products for optimal background rejection. It is shown that by the end of the 8 TeV run of the LHC, it might be possible to separate extreme hypotheses of the spin and parity of the new boson with a confidence level of 99% or better for a wide range of models. We briefly discuss the feasibility of testing scenarios where the more » resonances is not a parity eigenstate. « less

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/511b5491546a0e9557fdcc2f94a29d1de126b2e3

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Citations in the corpus

Evidence for the spin-0 nature of the Higgs boson using ATLAS data (2013, neutral): “Several approaches to describe such signatures can be found in the literature [12-17].”
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Les Houches 2017: Physics at TeV Colliders Standard Model Working Group Report (2017, background): “8 [826,827] generator, interfaced with Pythia 8 [633] for parton showering including the effect of hard gluon radiation.”
Measurements of the properties of the Higgs-like boson in the four lepton decay channel with the ATLAS detector using 25 fb$^{-1}$ of proton-proton collision data (2013, methodology): “For pairs of spin-parity states, a JP discriminant is formed, labelled JP-MELA3, from the ratio of this combined PDF for one of the spin-parity states to the sum of PDFs for both spin-parity states.”
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A framework for Higgs characterisation (2013, methodology): “Still, it is appropriate to check the results of the Higgs Characterisation model, in particular in view of other implementations available in the literature that aim at describing the same leading-order physics, and specifically that of JHU [10].”