712 research outputs found
Misura della sezione d'urto di produzione e ricerca di nuova fisica in eventi Z gamma gamma prodotti da collisioni protone protone a sqrt(s) = 13 TeV misurate dal detector CMS presso l'acceleratore LHC
No full textIn questa tesi viene presentato uno studio della produzione associata di un bosone Z e almeno due fotoni. L'analisi è stata condotta sfruttando collisioni protone protone, raccolte dall'esperimento CMS ad un'energia del centro di massa pari a 13 TeV, che corrispondono ad una luminosità integrata di 137 femtobarn inversi. Gli eventi di interesse sono ricostruiti in uno spazio delle fasi fiduciale selezionando coppie di leptoni, provenienti dal decadimento del bosone Z, accompagnati da almeno due fotoni isolati.
Le possibili sorgenti di fondo sono divise in due classi identificate come "prompt" e "non-prompt": la prima descrive gli eventi in cui i fotoni provengono dal vertice primario dell'interazione mentre la seconda contiene gli eventi in cui getti adronici sono ricostruiti come fotoni. La quantità di eventi contenuta nella categoria "non-prompt" è stata stimata con un metodo basato sui dati mentre quella "prompt" attraverso simulazioni.
La sezione d'urto fiduciale misurata è in accordo con la predizione del Modello Standard e la significatività osservata corrisponde a 4.8 deviazioni standard.
Gli eventi selezionati per la misura della sezione d'urto fiduciale sono anche usati per porre limiti a possibili accoppiamenti anomali dei bosoni di gauge, parametrizzati attraverso teorie di campo effettive. I limiti ottenuti sono compatibili e complementari ai risultati derivati da altri studi che utilizzano canali di produzione e decadimento alternativi.
Il lavoro presentato in questa tesi rappresenta il primo studio della produzione associata di un bosone Z ed almeno due fotoni ad un'energia del centro di mass pari a 13 TeV.A measurement of the production of a Z boson in association with two or more photons is presented. The analysis is based on proton proton collisions data collected by the CMS experiment, at a centre of mass energy of 13 TeV, and corresponding to an integrated luminosity of about 137 inverse femtobarns. Events are reconstructed in a fiducial phase space by selecting pairs of same flavour opposite sign leptons, originating from the Z boson decay, and at least two isolated photons.
The background contributions to this process are divided into two classes, "prompt" and "non-prompt", the former including events with genuine photons while the latter representing events where one or more reconstructed photons originate from hadrons decay inside jets. The non-prompt background source is estimated with a data-driven technique, while the prompt background source is estimated by using simulated events.
The measured fiducial cross section is in agreement with the Standard Model prediction and the observed significance corresponds to 4.8 standard deviations.
Events selected in the same phase space used for the fiducial cross section measurement are also exploited to set limits on several anomalous Quartic Gauge Couplings, in terms of dimension 8 effective field theory operators. The constraints obtained are compatible and complementary to other studies which use alternative production and decay channels.
This work represents the first study of the associated production of Z boson and at least two photons at a centre of mass energy of 13 TeV
Recent results on single vector boson plus jets production at CMS
No full textThe most recent results on the hadroproduction of an electroweak boson in association with one or more jets within the CMS experiment are presented. The cross section is studied differentially with respect to the transverse momentum and the angular correlation of the final state particles. Attention is given to the associated production of a vector boson plus flavour-tagged (b, c) jets. Comparison between data and different state-of-the-art theoretical predictions including (nextto)-leading-order corrections are presented as well
La trilogia dantesca di Federico Tiezzi
No full textThis co-authored paper examines the theatrical Trilogy devoted by Federico Tiezzi to the rewriting of Dante’s Comedy between 1989 and 1991. The canticas were rewritten for this occasion by the most important poets of the literary scene: Edoardo Sanguineti (Inferno), Mario Luzi (Purgatorio), Giovanni Giudici (Paradiso). The purpose of the analysis is to recover the comparison-conflict with Dante’s text, carried out by the authors through different strategies, as well as to find the unifying elements of dramaturgical work supervised by Tiezzi and his company, in which Sandro Lombardi stands out.In questo saggio scritto in due, si ripercorre la Trilogia teatrale dedicata da Federico Tiezzi alla riscrittura scenica della Commedia dantesca tra il 1989 e il 1991. Le cantiche erano state riscritte per l’occasione dai poeti più importanti della scena letteraria: Edoardo Sanguineti (Inferno), Mario Luzi (Purgatorio), Giovanni Giudici (Paradiso). Lo scopo dell’analisi è quella di recuperare il confronto-conflitto con il testo di Dante operato dagli autori con strategie diverse e di riscontrare gli elementi unificanti del lavoro drammaturgico sorvegliato da Tiezzi e dalla sua compagnia, in cui primeggia Sandro Lombardi
La trilogia dantesca di Federico Tiezzi
No full textIn questo saggio scritto in due, si ripercorre la Trilogia teatrale dedicata da Federico Tiezzi alla riscrittura della Commedia dantesca tra il 1989 e il 1991. Le cantiche erano state riscritte per l'occasione dai poeti più importanti della scena letteraria: Edoardo Sanguineti (Inferno), Mario Luzi (Purgatorio), Giovanni Giudici (Paradiso).Lo scopo dell'analisi è quella di recuperare il confronto-conflitto con il testo di Dante operato dagli autori con strategie diverse e di riscontrare gli elementi unificanti del lavoro drammaturgico sorvegliato da Tiezzi e dalla sua compagnia, in cui primeggia Sandro Lombardi.This co-authored paper examines the theatrical Trilogy devoted by Federico Tiezzi to the rewriting of Dante's Comedy between 1989 and 1991. The canticas were rewritten for this occasion by the most important poets of the literary scene: Edoardo Sanguineti (Inferno), Mario Luzi (Purgatorio), Giovanni Giudici (Paradiso).The purpose of the analysis is to recover the comparison-conflict with Dante's text, carried out by the authors through different strategies, as well as to find the unifying elements of dramaturgical work supervised by Tiezzi and his company, in which Sandro Lombardi stands out
Study of the linearity of the Electromagnetic Calorimeter of the Compact Muon Solenoid experiment using , and resonances
No full textThe work is divided into four chapters. In the first chapter the Standard Model is introduced, together with a short introduction on the Weak interactions and the Higgs theory. The Higgs boson main production and decay channels are presented, as well as the state of the art concerning its mass measurements. In the second chapter the LHC accelerator is briefly presented and the CMS experiment is described, focusing on the characteristics of its electromagnetic calorimeter ECAL, which is crucial for the identifications and measurements of the electrons in the four leptons Higgs decay channel. In the third chapter the algorithms for the electron energy reconstruction are presented. The various detector calibration methods are considered as well. In the fourth chapter the fine-tuning of the ECAL energy scale are presented together with the study of the residual non-linearity. The correction function to be applied to the electron energy from the decay of simulated Higgs boson events are derived and the systematic uncertainty on its reconstructed mass is evaluated
Measurement of the Z bosons production cross section and search for new physics in proton proton collisions at = 13 TeV with the CMS detector at the CERN LHC
No full textProbing the weak mixing angle at high energies at the LHC and HL-LHC
No full textMeasurements of neutral current Drell-Yan production at large invariant dilepton masses can be used to test the energy scale dependence (running) of the electroweak mixing angle. In this work, we make use of a novel implementation of the full next-to-leading order electroweak radiative corrections to the Drell-Yan process using the renormalization scheme for the electroweak mixing angle. The potential of future analyses using proton-proton collisions at in the Run 3 and High-Luminosity phases of the LHC is explored. In this way, the Standard Model predictions for the running at scales can be probed
Maestro di Sacro Palazzo
No full textLa voce traccia la figura del Maestro di Sacro Palazzo, le cui competenze censorie si intrecciarono spesso con quelle delle Congregazioni dell'Indice e del Sant'Uffizi
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