Ph.D. in Physics

Eventi del Dottorato

Dottorato in Fisica

Journal Club Seminari 2022

21/10/2022 ore 12:00
Aula F- primo piano - Via della Vasca Navale n. 84
ore 12:00 Federico Montereali
(DOTTORATO IN FISICA) Search for Higgs boson pair production in the two bottom quarks plus two photons final state in proton-proton collisions at LHC with the ATLAS detector
The Higgs boson self-coupling provides information about the structure of the Higgs potential and the self-coupling of the Higgs boson can be directly probed by studying Higgs boson pair (HH) production, that is an extremely rare process (non yet observed). At LHC, HH is mainly produced via gluon-gluon Fusion (ggF) and Vector-Boson Fusion (VBF) modes, that are affected by the trilinear self-interaction vertex. A deviation from the SM predicted self-coupling value may point to physics Beyond the Standard Model (BSM).
The search for Higgs boson pair production in the final state with two bottom quarks and two photons in proton-proton collisions at LHC, with data collected by the ATLAS detector and corresponding to an integrated luminosity of 139 fb$^{-1}$ will be presented. This final state is characterized by a small branching ratio (0.26%), but also by a clear experimental signature, thanks to the excellent di-photon invariant mass resolution, which makes it one of the "golden channels" for the HH searches.
The analysis strategies with possible techniques for improving sensitivity, and the recent results are discussed.
ore 12:45 Rita Antonietti
(DOTTORATO IN FISICA) Directional dark matter searches with CYGNO experiment -
The CYGNO experiment aims to exploit the optical readout approach of multiple Gas Electron Multipliers
(GEM) structures in large volume TPCs for the study of rare events as interaction of low-mass (few GeV)
Dark Matter (DM) or solar neutrinos. The TPC volume is filled with an He:CF4 gas mixture at atmospheric pressure. The photons produced in the multiplication process are read out by sCMOS sensors, which guarantees a high read granularity, a high sensitivity and a low noise level. The drift time of ionization is measured by PMTs in order to obtain the coordinate perpendicular to the camera plane.
The combined use of high-granularity sCMOS cameras and fast light sensors allows the reconstruction of the 3D direction of the tracks, offering good energy resolution and very high sensitivity in the few keV energy range. A detector sensitive to the incoming particle direction, in case of DM discovery, will be important in order to study its properties. The CYGNO experiment goal is to build and to operate a 1m3 demonstrator underground at the Gran Sasso National Laboratories (LNGS) aiming at a larger scale apparatus ({30 m^3−−100 m^3) at a later stage.
Chair:

info: journal club time table

ore 12:00	Federico Montereali (DOTTORATO IN FISICA)	Search for Higgs boson pair production in the two bottom quarks plus two photons final state in proton-proton collisions at LHC with the ATLAS detector The Higgs boson self-coupling provides information about the structure of the Higgs potential and the self-coupling of the Higgs boson can be directly probed by studying Higgs boson pair (HH) production, that is an extremely rare process (non yet observed). At LHC, HH is mainly produced via gluon-gluon Fusion (ggF) and Vector-Boson Fusion (VBF) modes, that are affected by the trilinear self-interaction vertex. A deviation from the SM predicted self-coupling value may point to physics Beyond the Standard Model (BSM). The search for Higgs boson pair production in the final state with two bottom quarks and two photons in proton-proton collisions at LHC, with data collected by the ATLAS detector and corresponding to an integrated luminosity of 139 fb$^{-1}$ will be presented. This final state is characterized by a small branching ratio (0.26%), but also by a clear experimental signature, thanks to the excellent di-photon invariant mass resolution, which makes it one of the "golden channels" for the HH searches. The analysis strategies with possible techniques for improving sensitivity, and the recent results are discussed.
ore 12:45	Rita Antonietti (DOTTORATO IN FISICA)	Directional dark matter searches with CYGNO experiment - The CYGNO experiment aims to exploit the optical readout approach of multiple Gas Electron Multipliers (GEM) structures in large volume TPCs for the study of rare events as interaction of low-mass (few GeV) Dark Matter (DM) or solar neutrinos. The TPC volume is filled with an He:CF4 gas mixture at atmospheric pressure. The photons produced in the multiplication process are read out by sCMOS sensors, which guarantees a high read granularity, a high sensitivity and a low noise level. The drift time of ionization is measured by PMTs in order to obtain the coordinate perpendicular to the camera plane. The combined use of high-granularity sCMOS cameras and fast light sensors allows the reconstruction of the 3D direction of the tracks, offering good energy resolution and very high sensitivity in the few keV energy range. A detector sensitive to the incoming particle direction, in case of DM discovery, will be important in order to study its properties. The CYGNO experiment goal is to build and to operate a 1m3 demonstrator underground at the Gran Sasso National Laboratories (LNGS) aiming at a larger scale apparatus ({30 m^3−−100 m^3) at a later stage.
Chair: