Investigating the trilinear self-coupling of the discovered Higgs boson is one of the main goals of particle physics in the near and far future. At the same time the quest for the existence of Higgs-like self interactions also provides a unique possibility in the search for new physics. BSM states can modify the trilinear Higgs coupling at the classical- or quantum-level, or contribute...
Understanding the renormalisation structure of extended Higgs sectors at higher orders is essential for obtaining precise and reliable theoretical predictions. In this work, we focus on the renormalization of the two-Higgs-doublet model (2HDM), and present a consistent renormalisation scheme for its scalar sector at two loops. A particular emphasis is placed on the treatment of the mixing...
The trilinear Higgs coupling $\lambda_{hhh}$ of the detected Higgs boson is a critical observable for understanding of the Higgs potential. With improving experimental bounds in the future, the theoretical predictions of this coupling for constraining BSM parameters become increasingly significant. Using the public code anyH3, this study investigates the numerical stability of different...
The next-to-minimal supersymmetric extension of the Standard Model (NMSSM) belongs to the most prominent, best motivated and experimentally widely tested beyond-SM extensions. For a meaningful interpretation of the experimental results and in order to be able to pin down the model underlying nature from the theory side, precise predictions for observables and parameters are crucial. Moreover,...
Several extensions of the Standard Model predict scalar states that are charged under QCD colour. Motivated by composite Higgs models, we study an electrically neutral colour octet and a colour sextet with charge 4/3. Both states couple to top quarks such that pair production leads to a four top quark signature. We train neural networks to separate these signal processes from their SM...
We propose angular observables sensitive to top-quark spin correlations to distinguish between the pseudoscalar $A\to ZH$ and the scalar $H\to ZA$ signals (where $A$ and $H$ denote CP-odd and CP-even Higgs bosons, respectively) in $Zt\bar t$ final states at the HL-LHC. Current searches performed by ATLAS and CMS are insensitive to the CP nature of BSM scalar states in the case of identical...
Composite Higgs models offer an elegant solution to the hierarchy problem by assuming that the Higgs boson is not an elementary particle but a composite state. The Higgs emerges as a pseudo-Nambu-Goldstone boson due to spontaneous symmetry breaking within a new strongly interacting sector.
We focus on minimal realizations of such models with fermionic UV completions that preserve custodial...
In recent years, Vector Boson Scattering (VBS) has been extensively stu-
died to gain a deeper understanding of the fundamental interactions and the
gauge structure of the Standard Model (SM). Additionally, it serves as a po-
werful probe for new physics processes at multi-TeV energy scales, offering
a window into physics beyond the Standard Model.
Composite Higgs models instead provide a...
High-energy $\gamma\gamma$- and $e\gamma$-collisions offer a rich phenomenological programme, complementary to $e^+e^-$ collisions at a linear collider both in kinematic as well as physics reaches. In particular, $\gamma\gamma$ collisions offer a unique setting to investigate properties of the Higgs boson(s). High polarisation of the photon beams (produced via Compton back-scattering) can be...
The nature of Dark Matter (DM) and the origin of small neutrino masses remain open questions in particle physics, motivating extensions of the Standard Model. In this talk, I explore Composite Higgs (CH) models that can simultaneously address both issues. As a concrete example, I will present a CH model based on the coset SU(6)/Sp(6), which naturally provides potential DM candidates as a...
Liquid argon Time Projection Chambers (LArTPCs) have proven to be powerful instruments for detecting weakly interacting particles predicted by many beyond the Standard Model (BSM) scenarios. Thanks to their location at CERN, the ProtoDUNE detectors can intercept a sizeable flux of such particles, produced when the 400 GeV protons from the Super Proton Synchrotron (SPS) impinge on a fixed...
We propose searching for physics beyond the Standard Model in the low-transverse-momentum tracks accompanying hard-scatter events at the LHC. TeV-scale resonances connected to a dark QCD sector could be enhanced by selecting events with anomalies in the track distributions. As a benchmark, a quirk model with microscopic string lengths was developed, including a setup for event simulation. For...
