Alberto Bragagnolo

The prevalence of Salmonella spp. infection was determined in 499 wild boars harvested during the 2010–2011 and 2011–2012 hunting seasons in the Latium Region of Italy. We conducted a microbiological assessment on faeces collected at slaughter and we examined serum samples for the presence of antibodies to Salmonella spp. by ELISA assay. Out of 383 serum samples examined, 255 (66.5%) were positive for Salmonella spp. antibodies. Overall, 10.8% (54/499) of the animals were positive by microbiological assessment. The Salmonellae most frequently isolated were S. enterica subsp. salamae II (24%), S. enterica subsp. Diarizonae III b (12.9%), S. enterica subsp. houtenae IV (11.1%) and S. Fischerhuette (7.4%); less common Salmonella isolates included S. Veneziana (5.5%), S. Napoli (5.5%), S. Kottbus (5.5%), S. Thompson (5.5%), S. enterica subsp. arizonae III a (3.7%), S. Toulon (3.7%), S. Burgas (1.8%), S. Tennelhone (1.8%), S. Ferruch (1.8%), S. choleraesuis (1.8%), S. Paratyphi (1.8%), S. Stanleyville (1.8%), S. Typhimurium (1.8%) and S. enterica subsp. enterica 4,5,12:1:- (1.8%). These isolates were tested against 16 antimicrobial agents and exhibited resistance to sulphonamides (92.5%), sulphonamides and thrimetroprim (14.8%), colistin (14.8%), streptomycin (18.5%), gentamycin (5.5%), tetracycline (5.5%), ceftiofur (3.7%), cefazoline (1.8%), cefotaxime (1.8%), nalidixic acid (1.8%), amoxicillin and clavulanic acid (1.8%) and ampicillin (3.7%). Our data, the first collected on this species in Italy, suggest that European wild boars are frequent carriers of antimicrobial-resistant Salmonellae and are likely involved in the transmission of antimicrobial resistance throughout the environment.

The Compact Muon Solenoid (CMS) experiment prepares its Phase-2 upgrade for the high-luminosity era of the LHC operation (HL-LHC). Due to the increase of occupancy, trigger latency and rates, the full electronics of the CMS Drift Tube (DT) chambers will need to be replaced. In the new design, the time bin for the digitization of the chamber signals will be of around 1 ns, and the totality of the signals will be forwarded asynchronously to the service cavern at full resolution. The new backend system will be in charge of building the trigger primitives of each chamber. These trigger primitives contain the information at chamber level about the muon candidates position, direction, and collision time, and are used as input in the L1 CMS trigger. The added functionalities will improve the robustness of the system against ageing. An algorithm based on analytical solutions for reconstructing the DT trigger primitives, called Analytical Method, has been implemented both as a software C++ emulator and in firmware. Its performance has been estimated using the software emulator with simulated and real data samples, and through hardware implementation tests. Measured efficiencies are 96 to 98% for all qualities and time and spatial resolutions are close to the ultimate performance of the DT chambers. A prototype chain of the HL-LHC electronics using the Analytical Method for trigger primitive generation has been installed during Long Shutdown 2 of the LHC and operated in CMS cosmic data taking campaigns in 2020 and 2021. Results from this validation step, the so-called Slice Test, are presented.

The CMS drift tubes (DT) muon detector, built for withstanding the LHC expected integrated and instantaneous luminosities, will be used also in the High Luminosity LHC (HL-LHC) at a 5 times larger instantaneous luminosity and, consequently, much higher levels of radiation, reaching about 10 times the LHC integrated luminosity. Initial irradiation tests of a spare DT chamber at the CERN gamma irradiation facility (GIF++), at large (∼ O(100)) acceleration factor, showed ageing effects resulting in a degradation of the DT cell performance. However, full CMS simulations have shown almost no impact in the muon reconstruction efficiency over the full barrel acceptance and for the full integrated luminosity. A second spare DT chamber was moved inside the GIF++ bunker in October 2017. The chamber was being irradiated at lower acceleration factors, and only 2 out of the 12 layers of the chamber were switched at working voltage when the radioactive source was active, being the other layers in standby. In this way the other non-aged layers are used as reference and as a precise and unbiased telescope of muon tracks for the efficiency computation of the aged layers of the chamber, when set at working voltage for measurements. An integrated dose equivalent to two times the expected integrated luminosity of the HL-LHC run has been absorbed by this second spare DT chamber and the final impact on the muon reconstruction efficiency is under study. Direct inspection of some extracted aged anode wires presented a melted resistive deposition of materials. Investigation on the outgassing of cell materials and of the gas components used at the GIF++ are underway. Strategies to mitigate the ageing effects are also being developed. From the long irradiation measurements of the second spare DT chamber, the effects of radiation in the performance of the DTs expected during the HL-LHC run will be presented.

During the High Luminosity LHC, the Drift Tube chambers installed in the CMS detector need to operate with an integrated dose ten times higher than expected at the LHC due to the increase in integrated luminosity from 300 fb-1 to 3000 fb-1. Irradiations have been performed to assess the performance of the detector under such conditions and to characterize the radiation aging of the detector. The presented analysis focuses on the behaviour of the high voltage currents and the dose measurements needed to extrapolate the results to High Luminosity conditions, using data from the photon irradiation campaign at GIF++ in 2016 as well as the efficiency analysis from the irradiation campaign started in 2017. Although the single-wire loss of high voltage gain observed of 70% is very high, the muon reconstruction efficiency is expected to decrease less than 20% during the full duration of High Luminosity LHC in the areas under highest irradiation.

This thesis describes the commission of the physics objects and analysis for the H->ττ search, covering two of the six inclusive channels, the μτ- and the eτ-channel. For this purpose the standard candle process of Z production into tau leptons has been studied. The result of this study was the measurement of the Z production cross section in proton-proton collisions. The main original work presented in this thesis is the development of a Tag and Probe workflow used to measure the identification, isolation and trigger efficiency for electron and muon objects in the ττ analyses context, needed to improve the agreement between data and simulation. This analysis was performed with data collected between March and August 2016 with the CMS detector at the LHC, corresponding to a total integrated luminosity of 12.9 fb^-1. The work presented in this thesis is part of the combined search of the SM and MSSM Higgs boson decay into two tau leptons by the CMS analysis group at the Deutsches Elektronen-Synchrotron (DESY) research center in Hamburg.

Il lavoro della presente tesi si inserisce nell'ambito dello sviluppo di foto-moltiplicatori al silicio per la rivelazione di fotoni nel lontano ultravioletto. Questa regione dello spettro della radiazione elettromagnetica e di notevole interesse in vari ambiti della fisica sperimentale. Ad esempio diversi recenti esperimenti di fisica fondamentale, come alcuni per la ricerca del doppio beta decay senza neutrini oppure per la ricerca di materia oscura, sono basati sulla rivelazione della scintillazione di gas nobili liquefatti quali Argon (128nm) o Xenon (175nm).

In recent years in the countries of the European Union have occurred profound and radical changes regarding the safety and hygiene of foodstuffs. The aim of this work is to highlight the significant changes made by the recent legislation in the control of Listeria monocytogenes.

These proceedings describe the measurement of the CP-violating phase $\phi_s$ using ${B_s^0\to J/\psi\,\phi(1020)}$ decays with the CMS experiment at $\sqrt{s} = 13$~TeV. The measurement is based on a data sample collected in 2017--2018 corresponding to an integrated luminosity of 96.4~fb$^{-1}$. A dedicated tagging trigger and a opposite-side muon flavour tagger based on deep learning techniques have been used in this analysis, significantly increasing the fraction of tagged events. The decay width (mass) difference $\Delta\Gamma_s$ ($\Delta m_s$) between the light and heavy $B_s^0$ mass eigenstates, the $B_s^0$ average decay width $\Gamma_s$ and the CP violation observable $| \lambda |$ are also measured. The combination with the results obtained by CMS at $\sqrt{s}=8$~TeV is also presented.

To sustain and extend its discovery potential, the Large Hadron Collider (LHC) will undergo a major upgrade in the coming years, referred to as High Luminosity LHC (HLLHC), aimed to increase its instantaneous luminosity, 5 times larger than the designed limit, and, consequently leading to high levels of radiation, with the goal to collect 10 times larger the original designed integrated luminosity. The drift tube chambers (DT) of CMS muon detector system is built to proficiently measure and trigger on muons in the harsh radiation environment expected during the HL-LHC era. Ageing studies are performed at the CERNs gamma ray irradiation facility (GIF++) by measuring the muon hit efficiency of these detectors at various LHC operation conditions. One such irradiation campaign was started in October 2017, when a spare MB2 chamber moved inside the bunker and irradiated at lower acceleration factors. Two out of twelve layers of the DT chamber were operated while being irradiated with the radioactive source and then their muon hit efficiency was calculated in coincidence with other ten layers which were kept on the standby. The chamber absorbed an integrated dose equivalent to two times the expected integrated luminosity of the HL-LHC. Investigation on the outgassing of cell materials and of the gas components used at the GIF++ are underway and strategies to mitigate the aging effects are also being developed. The effect of radiation on the performance of DT chamber and its impact on the overall muon reconstruction efficiency expected during the HL-LHC are presented.

These proceedings present the measurement of the weak CP-violating phase $\phi_s$ in the $B_s^0\to J/\psi\,\phi(1020)$ decay channel at $\sqrt{s} = 13$ TeV with the CMS experiment. The measurement is based on a data sample corresponding to an integrated luminosity of 96.4 fb$^{-1}$, collected in 2017--2018. This analysis employs a dedicated tagging trigger and a novel opposite-side muon flavor tagger based on deep learning techniques. The decay width (mass) difference $\Delta\Gamma_s$ ($\Delta m_s$) between the light and heavy $B_s^0$ mass eigenstates, the $B_s^0$ average decay width $\Gamma_s$ and the CP violation observable $\left| \lambda \right|$ are also measured. The combination with the results obtained by CMS at $\sqrt{s}=8$ TeV is also presented.

The latest results on flavour anomaly from ATLAS and CMS are here presented.Four recent studies are discussed: the first CMS search for the τ → 3µ decay, the CMS angular analysis of the B + → K + µ + µ -decay, and the B 0 → K * 0 µ + µ -angular analyses by ATLAS and CMS, with respective HL-LHC projections.This last study is of particular interest, due to indications of discrepancy with respect to the Standard Model from previous measurements by LHCb and Belle.All results presented in these proceedings are in agreement with the Standard Model.