Contribution to a book

A set of measurements involving the t$\bar{\text{t}}$ production and the fermion associated t$\bar{\text{t}}$ production is presented. Data were recorded from proton-proton collisions at the CERN's LHC with the CMS detector, at a center-of-mass energy of 13 and 13.6 TeV. [...]

We present an analysis of the sensitivityof LHC searches for new spin-0 particlesproduced via gluon-fusion and decaying intotop-antitop-quark ($t\bar{t}$) final statesto generic axion-like particles (ALPs)coupled to top-quarks and gluons.We derive new limits on the effective ALPLagrangian in the linear representationin terms of the Wilsoncoefficients $c_{t}$ and $c_{\tilde{G}}$based on the existingCMS search using $35$ fb$^{-1}$ of proton-proton scattering data collectedat $\sqrt{s} = 13$ TeV. We further investigate posssible distinctions between ALPs and pseudoscalarHiggs bosons as predicted by the Two Higgs doublet model (2HDM), and find that a distinction is possiblewith data anticipated to be collectedduring the high-luminosity phase of the LHCfor a significant range of the effective ALP-gluon coupling..

The search for lepton-flavor violating decays of the Higgs boson to an electron-muon pair using data from proton-proton collisions at $\sqrt{s} = 13$ TeV collected by the CMS experiment at the LHC is presented. The dataset corresponds to an integrated luminosity of $138 fb^{-1}$. [...]

Recent measurements of the inclusive $\mathrm{t\overline{t}}$ production cross section, $\sigma_\mathrm{t\overline{t}}$, and the ratio of $\mathrm{t\overline{t}}$ to Z boson production, $R_{\mathrm{t\overline{t}}/\mathrm{Z}}$, are presented by the CMS and ATLAS collaborations using data collected from proton-proton collisions at the new LHC operating energy of $\sqrt{s}=13.6$ TeV. These are among the first results of the ongoing LHC Run 3 data-taking period, which began in 2022, and provide a first opportunity to measure changes in key physics observables following the increase in energy. [...]

Awareness of the need for FAIR data management has increased in recent years but examples of how to achieve this are often missing. Focusing on the large-scale instrument A4 at the MAMI accelerator, we transfer findings of the EMIL project at the BESSY synchrotron* to improve raw data, i.e. [...]

Due to improvements of the performance of FELs, the measurements of the beam’s slice energy spread is becoming increasingly important for optimization of the brightness. Of particular interest are measurements of the uncorrelated energy spread near the gun as this determines the lower limit of the energy spread for the rest of the machine. [...]

A single-pass THz free-electron laser (FEL) at the PhotoInjector Test facility at DESY in Zeuthen (PITZ) was designedand realized for proof-of-principle experiments ona tunable high-power THz source for pump-probe experimentsat the European XFEL. THz pulses are generated ata radiation wavelength of ~100 um within a 3.5 m long,strongly focusing planar LCLS-I undulator. [...]

The first operational high peak and average power THz self-amplified spontaneous emission (SASE) free electron laser (FEL) at the Photo Injector Test facility at DESY in Zeuthen (PITZ) has demonstrated up to 100 μJ single pulse energy at a center frequency of 3 THz from electron bunches of 2-3 nC. The measured shot-to-shot radiation pulse energy has a fluctuation of 10%. [...]

An ultrafast laser system for driving the photocathode RF gun at the European XFEL has been recently put into operation. The new laser system, NExt generation PhotocAthode Laser (NEPAL) is capable of providing drive laser pulses of variable pulse lengths and shapes, supporting the facility to extend its capabilities to operate in multiple user-desirable FEL modes. [...]