The Composite 2-Higgs-Doublet Model (C2HDM) is a composite Higgs Model where two Higgs doublets arise as pseudo Nambu-Goldstone bosons in order to retrieve the well known 2HDM but with couplings already predetermined by the composite nature of the model. Fermion masses are generated through partial compositeness entailing new heavy fermions. In this talk we present Higgs Pair production in...
In practical applications for effective field theories, it is often necessary to obtain a complete set of independent operators, but constructing such an operator basis is remarkably challenging. In this talk, I will report on our implementation of a recently proposed group-theoretical algorithm that systematically accounts for the redundancies arising from equations of motion and...
We present a novel formalism to calculate jet functions automatically at next-to-next-to-leading
order in perturbation theory. By employing suitable phase-space parameterisations in combination with
sector-decomposition steps and selector functions, we managed to factorise all divergences in the
phase-space integrations, and we implemented our framework in the publicly available code...
After providing a quick overview of what my daily work entails, I will offer a few remarks about my decision of leaving academia and personal experience of applying to several (German) companies. I plan to leave enough time for discussion, so bring your own questions!
I will present our calculation of massive quark form factors at three loops in QCD.
After reducing the Feynman integrals in the amplitudes to master integrals, these were computed by solving differential equations. By constructing expansions around regular as well as singular points and numerical matching, we obtain sufficient precision over the whole kinematic range.
Ultra-relativistic particles can be produced by the decay of weak-scale LLPs and act as dark radiation. The cosmologically interesting range $\Delta N_\text{eff} \sim 0.01–0.1$ corresponds to LLP decay lengths at the mm scale. These decay lengths lie at the boundary between prompt and displaced signatures at the LHC. We consider a scenario where the LLP decays into a lepton and a (nearly)...
I will discuss a flavoured dark matter (DM) model set up in the so called Dark Minimal Flavour Violation (DMFV) framework. The model extends the Standard Model by a DM flavour triplet and a scalar mediator, through which the new dark fermions couple to right-handed up-type quarks. This interaction is governed by a new coupling matrix which is assumed to constitute the only new source of...
In this talk we estimate the potential size of the weak annihilation amplitudes in QCD factorization as allowed by experimental data by establishing a connection between the amplitudes in the QCD factorization and the so-called topological and SU(3)-invariant descriptions. Our approach is based purely on the analysis of the tensor structure of the decay amplitudes. By focusing on the decay...
(Part of the CRC project C1b)
In this talk, I plan to discuss the current status of theory predictions for lifetimes of heavy $H = B, D$-mesons (containing a heavy quark $Q = b,c$), which can be presented schematically within the Heavy Quark Expansion (HQE) framework as:
$$
\Gamma(H) =
\Gamma_3 +
\Gamma_5 \frac{\langle {\cal O}_5 \rangle}{m_Q^2} +
\Gamma_6 \frac{\langle {\cal O}_6...
We present the current status of work to determine non-perturbative contributions to the physics of $B$-mesons.
Using the methods of lattice QCD, QCD sum rules, and the gradient flow, we consider quantities such as decay constants, dimension-6 and -7 matrix elements for lifetimes, and dimension-7 matrix elements for mixing.
We present analytical results for higher order corrections to the decay spectrum of inclusive semileptonic heavy hadron weak decays using the heavy quark expansion (HQE). We describe the analytical computation of the spectrum of the leptonic invariant mass for $B\rightarrow X_c \ell \bar{\nu}$ up to terms of order $1/m_b^3$ within the HQE at next-to-leading order (NLO) in $\alpha_s$. The full...
We report on the calculation of the Higgs production and decay in association with top quarks in the di-leptonic channel at NLO QCD. All resonant, non-resonant Feynman diagrams and off-shell effects are included for the top quark and $W$ boson. We examine the size of these off-shell effects by a comparison to the narrow-width approximation. Higgs boson decays are included in the narrow-width...
In the Standard Model, the Higgs boson is predicted to be a scalar particle. However, a possible admixture of a $\cal{CP}$-odd component has yet to be excluded experimentally.
In this talk, I will present predictions for the associated production of a top-quark pair and a stable Higgs boson $pp\to e^+\nu_e\,\mu^-\bar{\nu}_\mu\,b\bar{b}\,H$ with possible mixing between $\cal{CP}$-even and ...
The Higgs boson production channel $t\bar{t}H(H\rightarrow b\bar{b})$ is a crucial ingredient to study the top-Yukawa coupling but suffers of a huge background. The direct $ t\bar{t}b\bar{b}$ production represents one of the main backgrounds to this process and, therefore, needs to be described properly. In this talk I will present the latest theoretical results obtained in the dileptonic...
I will present a sensitivity test of the muon-Higgs coupling at a high-energy muon collider. This is motivated if there exists new physics that is not aligned with the Standard Model Yukawa interactions which are responsible for the fermion mass generation. With the accidentally small value of the muon Yukawa coupling and its subtle role in the high-energy production of multiple (vector and...
We will discuss a novel framework for addressing QCD factorization in the emission of multiple soft or collinear partons. The purpose of this discussion is to allow for a more precise description of hadron collider data and to better handle theoretical uncertainties from parton showers.
We have developed a power counting algorithm in emission amplitudes with the goal of parameterizing the...
In this talk, I will present the analytic calculations of leading two-loop Yukawa corrections to the Higgs pair production in the high energy limit. These corrections are introduced by exchanging a virtual Higgs boson between top-quark lines. In particular, I will discuss the Mellin-Barnes and differential-equation methods for the calculations of fully massive two-loop box master integrals in...
We present results for Higgs boson pair production in gluon fusion
including both, NLO (2-loop) QCD corrections with full top quark
mass dependence as well as anomalous couplings related to operators
describing effects of physics beyond the Standard Model. The latter
can be realized in non-linear (HEFT) or linear (SMEFT) Effective
Field Theory frameworks. We show results for both and discuss...
By extending the 2-Higgs Doublet Model (2HDM) by scalar dimension-6 effective field theory (EFT) operators we investigate to which extent the addition of these higher-dimensional operators can promote the electroweak phase transition to a strong first-order electroweak phase transition (SFOEWPT). We analyze the interplay between the choice of Wilson coefficients inducing an SFOEWPT and the...
