We study the production of a single resonance at the LHC and its decay into a pair of Z bosons. We demonstrate how full reconstruction of the final states allows us to determine the spin and parity of the resonance and restricts its coupling to vector gauge bosons. Full angular analysis is illustrated with the simulation of the production and decay chain including all spin correlations and the most general couplings of spin-zero, -one, and -two resonances to Standard Model matter and gauge fields. We note implications for analysis of a resonance decaying to other final states.Comment: 29 pages, 5 figures, supporting material, typos fixe

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, W W , and γγ. A complete Monte Carlo simulation of the process pp → X → V V → 4f is performed and verified by comparing it to an analytic calculation of the decay amplitudes X → V V → 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 resonances is not a parity eigenstate.

We present precise predictions for Higgs boson production in association with a jet. We work in the Higgs effective field theory framework and compute next-to-next-to-leading order QCD corrections to the gluon-gluon and quark-gluon channels, which is sufficient for reliable LHC phenomenology. We present fully differential results as well as total cross sections for the LHC. Our next-to-next-to-leading order predictions reduce the unphysical scale dependence by more than a factor of 2 and enhance the total rate by about twenty percent compared to next-to-leading order QCD predictions. Our results demonstrate for the first time satisfactory convergence of the perturbative series.

In this paper, we study the extent to which CP parity of a Higgs boson, and more generally its anomalous couplings to gauge bosons, can be measured at the LHC and a future electron-positron collider. We consider several processes, including Higgs boson production in gluon and weak boson fusion and production of a Higgs boson in association with an electroweak gauge boson. We consider decays of a Higgs boson including ZZ; WW; γγ, and Zγ. A matrix element approach to three production and decay topologies is developed and applied in the analysis. A complete Monte Carlo simulation of the above processes at proton and e þ e − colliders is performed and verified by comparing it to an analytic calculation. Prospects for measuring various tensor couplings at existing and proposed facilities are compared.

We report on a calculation of the cross-section for Higgs boson production in gluon fusion in association with a hadronic jet at next-to-next-to-leading order (NNLO) in perturbative QCD. The computational technique is discussed in detail. We show explicitly how to employ known soft and collinear limits of scattering amplitudes to construct subtraction terms for NNLO computations. Cancellation of singularities is demonstrated numerically for the collinearly-subtracted gg → H + j cross-section through NNLO and the finite σ gg→Hj cross-section is computed through O(α 5 s ) as a function of the center-of-mass collision energy. We present numerical results for the gluon-fusion contribution to Higgs production in association with a jet at the LHC. The NNLO QCD corrections significantly reduce the residual scale dependence of the cross-section. The computational method that we describe in this paper is applicable to the calculation of NNLO QCD corrections to any other 2 → 2 process at a hadron collider without modification.

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We present results for the next-to-leading order QCD corrections to the production and semi-leptonic decays of a top quark pair in hadron collisions, retaining all spin correlations. To evaluate the virtual corrections, we employ generalized Ddimensional unitarity. The computation is implemented in a numerical program which allows detailed studies of tt-related observables at the Tevatron and the LHC. §

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