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[en] For the New Small Wheel (NSW) project the innermost end-cap of the ATLAS muon spectrometer will be replaced. This part of the muon tracking system will use the sTGC and Micromegas detector technologies. The high density of the readout channels of both detector installations results in a high density of the Front-End readout boards (FEBs). To extend the service time of the FEBs their cooling is necessary. To achieve this goal, an approach that enables FEB cooling with a combination of custom design aluminium plates and heat conducting gap pad was developed and studied. Furthermore, a method for the heat transfer from the transceivers, which are located on the FEB side opposite to the cooling installations, was developed. Four types of measurements were executed to test applicability of both cooling solutions under the NSW cooling system constraints. The presentation focuses on the cooling test results of the MMFE-8 production board and L1DDC transceivers. The constraints of each task are described and test results of the implemented solution are discussed.
[en] The Karlsruhe Tritium Neutrino (KATRIN) experiment aims to measure the effective electron anti-neutrino mass with a sensitivity of 0.2 eV (90% C.L.) by investigating the endpoint region of the decay spectrum. The experimental setup of KATRIN consists of a tritium source, from which the decay electrons are magnetically guided through the transport section towards two Mac-E filters (pre- & main spectrometer). The spectrometers act as integrating high pass filters with an energy resolution defined by the magnetic field strength in the spectrometer's center and the Pinch magnet. Only electrons near the energetic endpoint of the decay spectrum are transmitted to the detector. A precise magnetic field model is of high importance for the neutrino mass analysis, as slight magnetic field deviations can significantly influence the spectrometer's energy resolution. This poster presents a method to precisely determine the magnetic field inside of the main spectrometer based on field values measured outside of the vessel, with KATRIN's radial magnetic monitoring system. The systematic uncertainty of the model is analyzed as a function of the applied magnetic field setting. The results of the study are essential for deciding which magnetic field setting to use in the first neutrino mass measurements.
[en] Due to it's ability to measure even under extreme conditions such as full moon nights in combination with it's completely automatic data taking system, the First G-APD Air Cherenkov Telescope (FACT) is well suited for the long term observation of gamma-ray sources. Since the first light in 2011, more than seven years of data from several sources has been acquired, in particular also from two of the brightest TeV-blazars Mrk421 and Mrk501. This allows an unprecedented insight into the variability of these objects. Extracting spectra and combining them with other multi-wavelength data allows to compile time-resolved spectral energy distributions challenging most models. In this context, a recent model is studied. It is based on particle-in-cell (PIC) simulations of reconnection driven plasmoids forming in a blazar's jet. In contradiction to most used steady state models, it directly provides predictions on the temporal behavior which can be compared with experimental data.
[en] Since the LHC has not provided us with any hints towards new physics, it is ever more interesting to constrain BSM theories from purely theoretical considerations. Requiring that the electroweak vacuum in any BSM model is at least metastable can lead to stringent constraints on the parameter space of the model. Many popular extensions of the SM, such as supersymmetry, feature greatly extended scalar sectors. In the resulting high dimensional scalar potential, vacuum decay can happen in many different field directions. Constraints from vacuum decay thus rely on finding all minima of multidimensional scalar potentials which is a nontrivial task even at tree-level. We present results on the vacuum stability in supersymmetric models from a new code aiming to provide an efficient and reliable check of vacuum stability for use in BSM parameter scans.
[en] Many models of physics beyond the Standard Model (SM) predict the existence of new spin 1 gauge bosons that could be discovered by experiments at the Large Hadron Collider (LHC). In the leptonic decay channel the massive charged W boson decays into a lepton and a neutrino. The analysis requires a single high- isolated lepton (l = e, and substantial missing transverse energy originating from the undetected neutrino. The signal discriminant is the transverse mass m = where ist the angle between the lepton and in the transverse plane. The existence of a W boson could lead to an excess of data in the high transverse mass region. From 2015 to 2017 the LHC provided proton collisions at a center of mass energy of 13 TeV. Data corresponding to an integrated luminosity of about 70 fb has been recorded by the ATLAS experiment. The analysis strategy and an understanding of the data used in the search for narrow resonance like structure in l + final state will be presented.