Silvan Kuttimalai

Mass effects in the Higgs-gluon coupling: boosted vs. off-shell production

A bstractIn the upcoming LHC run we will be able to probe the structure of the loopinduced Higgs-gluon coupling through kinematics. First, we establish state-of-the-art simulations with up to two jets to next-to-leading order including top mass effects. They allow us to search for deviations from the low-energy limits in boosted Higgs production. In addition, the size of the top mass effects suggests that they should generally be included in Higgs studies at the LHC. Next, we show how off-shell Higgs production with a decay to four leptons is sensitive to the same top mass effects. We compare the potential of both methods based on the same top-Higgs Lagrangian. Finally, we comment on related model assumptions required for a Higgs width measurement.

Beyond standard model calculations with Sherpa

We present a fully automated framework as part of the Sherpa event generator for the computation of tree-level cross sections in Beyond Standard Model scenarios, making use of model information given in the Universal FeynRules Output format. Elementary vertices are implemented into C++ code automatically and provided to the matrix-element generator Comix at runtime. Widths and branching ratios for unstable particles are computed from the same building blocks. The corresponding decays are simulated with spin correlations. Parton showers, QED radiation and hadronization are added by Sherpa, providing a full simulation of arbitrary BSM processes at the hadron level.

Higgs-Strahlung: Merging the NLO Drell-Yan and Loop-Induced 0+1 jet Multiplicities

We analyze the production of a Higgs boson in association with a Z boson at hadron colliders in the Standard Model and some simple extensions. We show how multijet merging algorithms at leading and next-to-leading order for the loop-induced gluon fusion and the Drell-Yan-like quark-induced processes, respectively, improve the descriptions for various differential distributions, in particular those that involve the production of additional jets. The phenomenological studies focus on two relevant channels of Higgs boson decays, namely H→invisible and H→bb¯. We find sizable and phenomenologically relevant corrections to the transverse momentum and invariant mass distributions for the Higgs boson candidate. Thanks to the large destructive interference for the top Yukawa terms, this process is very sensitive to the magnitude and sign of a possible nonstandard top-Higgs coupling. We analyze the impact of this anomalous interaction on distributions and estimate constraints from LHC Run II.

LHC multijet events as a probe for anomalous dimension-six gluon interactions

Higher-dimensional multigluon interactions affect essentially all effective Lagrangian analyses at the LHC. We show that, contrary to common lore, such operators are best constrained in multijet production. Our limit on the corresponding new physics scale in the multi-TeV range exceeds the typical reach of global dimension-six Higgs boson and top analyses. This implies that the pure Yang-Mills operator can safely be neglected in almost all specific higher-dimensional analyses at Run II.

Boosting invisible searches via ZH : From the Higgs boson to dark matter simplified models

Higgs boson production in association with a

Aspects of perturbative QCD at a 100 TeV future hadron collider

Z

Standard Model processes

-boson at the LHC is analysed, both in the Standard Model and in Simplified Model extensions for Dark Matter. We focus on

Measuring rare and exclusive Higgs boson decays into light resonances

H\rightarrow

Hadronic Final States in DIS at NNLO QCD with Parton Showers.

invisibles searches and show that loop-induced components for both the signal and background present phenomenologically relevant contributions to the

Assault on the Nastiest Effective Operator at the LHC

\mathcal{BR}(H\rightarrow\textit{inv})