Related papers: Generalized angular-order parton showers in Herwig…
We present the first combination of NLO QCD matrix elements for di-Higgs production, retaining the full top quark mass dependence, with a parton shower. Results are provided within both the POWHEG-BOX and MadGraph5_aMC@NLO Monte Carlo…
Spin correlations are an important, but often neglected, effect in modern Monte Carlo event generators. We show that they can be fully incorporated in Herwig 7 using the algorithm originally proposed by Collins and Knowles in all stages of…
The Brout-Englert-Higgs mechanism describes the generation of masses of fundamental particles in the Standard Model (SM). It predicts the existence of one scalar particle with precisely predicted couplings to fermions and gauge bosons.…
The merging of matrix elements and parton showers is an established calculational tool for the description of multi-jet final states at hadron colliders. These methods have recently been promoted to next-to-leading order accuracy in the…
High-quality simulated data is crucial for particle physics discoveries. Therefore, parton shower algorithms are a major building block of the data synthesis in event generator programs. However, the core algorithms used to generate parton…
The angular distributions in the Higgs-strahlung process $e^+e^-\to HZ\to H\bar f f$ are uniquely determined in the Standard Model. We study how these predictions are modified if non-standard couplings are present in the $ZZH$ vertex, as…
A method for incorporating information from next-to-leading order QCD matrix elements for hadronic diboson production into showering event generators is presented. In the hard central region (high jet transverse momentum) where perturbative…
In this article we describe simulations of Higgs boson production via the gluon fusion and Higgs-strahlung processes, using the positive weight next-to-leading-order (NLO) matching scheme, POWHEG, in the Herwig++ 2.3 event generator. This…
At the Forschungszentrum Juelich (FZJ) we have started a long-term program that aims to determine beyond-the-Standard-Model (BSM) matrix elements using the gradient flow, and to understand the impact of BSM physics in nucleon and nuclear…
The foundations of the mass generation mechanism of particles are reviewed. The Spontaneous Symmetry Breaking (SSB) process within the standard model (SM) and the minimal supersymmetric standard model (MSSM) is used to explore the present…
We describe the program HERWIRI2.1, which implements order alpha-squared photonic radiative corrections exponentiated at the amplitude level (initial state, final state, and initial-final interference) and electroweak corrections to the…
We present the cross section for $e^{+}e^{-}\to hZ$ with arbitrary sets of electron and $Z$ boson polarizations at the full next-to-leading order in various extended Higgs models, such as the Higgs singlet model (HSM), the inert doublet…
We consider the production of a Standard-Model (SM) Higgs boson in gluon fusion in hadronic collisions and compute the QCD corrections up to next-to-next-to-leading order (NNLO) and match them to parton showers (NNLO+PS). The complete…
We present results of the simulation of electroweak Higgs boson production at the Large Hadron Collider using both the NLO multijet merging and NLO matching frameworks provided by the general purpose event generator Herwig 7. For the…
We develop a Monte Carlo event generator for Higgs Boson pair production merged to exact one-jet matrix elements. The matrix elements are generated with OpenLoops and event generation is performed with the HERWIG++ general-purpose event…
We analyze the rare decay mode $B \to \phi \pi $, which is a pure penguin induced process, receiving dominant contribution from the electroweak penguins. Thus the standard model branching ratio is expected to be very small, which makes it…
There exist tree-level generalizations of the Type-I and Type-III seesaw mechanisms that realize neutrino mass via low-energy effective operators with d>5. However, these generalizations also give radiative masses that can dominate the…
The review of developed by the authors new techniques for covariant calculation of matrix elements in QED, the so-called formalism of "Diagonal Spin Basis" (DSB), is presented. In DSB spin 4-vectors of in- and out- fermions are expressed…
Deviations in the trilinear self-coupling of the Higgs boson at 125 GeV from the Standard Model (SM) prediction are a sensitive test of physics Beyond the SM (BSM). The LHC experiments searching for the simultaneous production of two Higgs…
One of the main theoretical systematics in studies of final states with large jet multiplicities at high-energy hadron colliders is associated with the merging of QCD parton showers and hard-scattering matrix elements. We present a method…