We explore the real-singlet extension of the Standard Model without a Z2 symmetry (RxSM), as a model to reconstruct the Higgs potental and explain the baryon asymmetry of the Universe. First, we determine regions of parameter space that allow a Strong First-Order Electroweak Phase Transition (SFOEWPT) using the public tools CosmoTransitions and TransitionListener, including also relevant...
We investigate the reliability of a comparison between the experimental results and the theoretical predictions for the pair production of the 125 GeV Higgs boson at the LHC. Recent experimental results for di-Higgs production provide already sensitivity to triple Higgs couplings (THCs) in models beyond the Standard Model (BSM). In our analysis within the Two Higgs Doublet Model (2HDM) we find...
Various extensions of the Standard Model predict the existence of additional Higgs bosons. If these additional Higgs bosons are sufficiently heavy, an important search channel is the di-top final state. In this channel, interference contributions between the signal and the corresponding QCD background process are expected to be important. If more than one heavy scalar is present, besides the...
(Meta)stability of the EW vacuum is a crucial requirement for models with extended scalar sectors, which puts strong constraints on the parameter space of such models. In this work, we compare the vacuum structure of two extended scalar models, namely N2HDM (2HDM+real singlet) and 2HDMS (2HDM+complex singlet) and the intrinsic difference between them. We further investigate whether such...
In this talk I will focus on the study of the leptonic $B^-\rightarrow\ell^- \bar{\nu}_\ell$
at next-to-leading order in QED. The future improvements of experimental measurements of this channel require a reliable theory prediction, hence a careful theoretical estimate of QED corrections. The multi-scale character of this process requires an appropriate effective theory (EFT) construction to...
We investigate the possibility of disentangling different new physics contributions to the rare meson decays $K\rightarrow\pi+$invisible and $B\rightarrow K(K^*)+$invisible through kinematic distributions in the missing invariant mass squared. We employ dimension-$6$ operators within the Low-Energy Effective Field Theory (LEFT), identifying the invisible part of the final state as either...
In this talk, we present a flavour non-universal UV completion of the Standard Model aimed at addressing the Higgs hierarchy problem and the flavour puzzle. In the UV, a flavour non-universal gauge sector is spontaneously broken down by non-perturbative dynamics. The Higgs emerges as a light pseudo-Nambu-Goldstone boson of the broken symmetry, and its potential is radiatively generated by...
Ultralight candidates for dark matter can present wavelike features on astrophysical scales. Full wave based simulations of such candidates are currently limited to box sizes of 1-10 Mpc/$h$ on a side, limiting our understanding of the impact of wave dynamics on the scale of the cosmic web. We present a statistical analysis of density fields produced by perturbative forward models in boxes of...
The compelling evidence for the detection of the stochastic gravitational wave background by NANOGrav imposes constraints on the mass of compact cores of ultra-light dark matter, also known as “solitons”, surrounding supermassive black holes found at the centers of large galaxies. The strong dynamical friction between the rotating black holes and the solitons competes with gravitational...
Ultra-light dark matter models, which feature particles whose masses are so light that their behavior can be treated as a collective wave rather than individual particles, are an intriguing alternative to “standard” cold dark matter. They feature a rich and unique phenomenology on astrophysical scales, with implications for small-scale tensions. The most well-studied member of this family is...
Axionlike particles (ALPs) are promising candidates for dark matter. A tiny interaction between photons and ALPs gives rise to achromatic birefringence. The birefringence angle oscillates with a time period determined by ALP mass. We exploit this property of ALPs to find stringent constraints on its coupling constant as well as mass by means of radio polarimetric observations of strong...
In this talk, we address the impact of the hot plasma during dark matter production via freeze-in. In particular, we study a model that features a feebly-interacting real scalar and a vector-like mediator. Recent work has shown that, in contrast to freeze-out production in the context of WIMPs, freeze-in production is sensitive to thermal corrections. While previous calculations had not...
I demonstrate the possibility to perform a parametrically improved search for gauged baryon ($B$) and baryon minus lepton ($B-L$) Dark Photon Dark Matter (DPDM) using auxiliary channel data from LISA Pathfinder. In particular I point out the use of the measurement of the differential movement between the test masses (TMs) and the space craft (SC) which is nearly as sensitive as the tracking...
