Particle Physics

ITALIAN VERSION

Title Typology Supervisor Description
Search for invisible decays of a dark force mediator boson through the observation of single photon events in KLOE-2 Instrumental/
Data analysis

S. Giovannella

The activity will focus, on the detector side, on setting up, monitoring and measuring the performance of a dedicated single photon trigger in KLOE-2 apparatus. On the analysis side, pre-selection of interesting events, usage of all the possible tools to reject the physics and machine background and, finally, signal isolation and exclusion limits calculation (or discovery significance) will be required.
Precision measurement of the π0 radiative width at KLOE-2 Data analysis

C. Bloise

The KLOE-2 experiment is taking data at DAFNE. More than three out of five fb-1 have been recorded to date. A tagger system for the detection of final-state leptons from γ-γ processes, e+e → e+e γ*γ*→e+e X, was installed on DAFNE and continuously operated since the very beginning of the data taking campaign, in November 2014. Per-cent precision in the π0 radiative width measurement is the target for testing very fundamental predictions of QCD in the low-energy regime, and can be achieved with KLOE-2 removing background from data at the φ-resonance firstly exploiting the tagger system.
Search for “Dark Photon” using positron on target collision at DAFNE (PADME) Simulation/
Analysis

P. Gianotti

Astronomical and cosmological observations show the existence of non-ordinary forms of matter: “dark matter”. The PADME experiment at DAFNE aims at detecting signals of light dark matter particles making the positron beam of the DAFNE complex interacting with a thin nuclear target. The thesis work consists in the development of the Montecarlo simulation and tracking software of the experimental apparatus.
Development of a beam tracking system for the “Dark Photon” PADME experiment Instrumental

E. Spiriti

The PADME experiment aims to look for signals of light dark photons produced following the annihilation of positrons on a thin carbon target. The tracking with high precision and efficiency of the beam is fundamental for the success of the experiment and for that reason it is foreseen to realize a monitoring system with silicon pixel detectors. The thesis work consists in the development and construction of thin pixel silicon detectors to be placed inside and/or close to the vacuum chamber of the experiment and in the development of the data acquisition and analysis software of these detectors.
Test of new physics beyond the Standard Model at the NA62 experiment at CERN Data analysis

T. Spadaro

The thesis work foresees feasibility studies and analyses of data collected in 2016 and 2017 for new physics searches within NA62, an experiment at CERN SPS. The main goal of the experiment is the measurement of the rare decay rate of K+ in a charged pion and a neutrino-antineutrino pair. This physics case, together with a series of studies regarding the search of particles of the “hidden” sector (candidates or mediators of dark matter), showed sensitivity to possible new physics contributions and tests regions of the parameter’s space (masses of mediators, couplings) accessible at LHC. The NA62/LNF group is involved in this field and collaborate with different groups in Italy, UK, Czech Republic, Mainz and CERN.

Lepton universality test through of the study of semi-tauonic decays of heavy hadrons at LHCb Data analysis

M. Rotondo

In this thesis work we propose to study semitauonic decays Bs → Ds(*,**) τ ν, which give a complementary information to channels already studied. With the statistics of data already collected at LHCb it is possible to realize a significant test of possible contributions beyond the Standard Model. The thesis work foresees periods at CERN for data taking, results presentation and discussion.
Study of rare decays at LHCb to search for hints of new physics beyond the Standard Model Data analysis

B. Sciascia

The recent observation of the Bs → μ+μ decay, performed with a joint analysis of the LHCb and CMS experiments, is certainly one of the most important results achieved at the LHC that allowed to set stringent limits to many Standard Model extensions, like supersymmetric ones. The goal of this thesis work is to push further this research and in particular to measure the ratio of the branching fractions of Bd → μ+μ and Bs → μ+μ  decays; this ratio is precisely predicted by the Standard Model and any violation of this prediction would represent an experimental evidence of new physics beyond the Standard Model. The thesis work foresees periods at CERN for data taking, results presentation and discussion.

Study and development of an internal target for LHC for the LHCb experiment Instrumental

P. Di Nezza

The realization of an internal target, possibly polarized, to be installed at the LHC, within the LHCb collaboration, offers the possibility to have the first collider at the highest reached energy able to operate with gaseous target. This perspective will open an unexplored scenario either in the development of the needed technology and in the possible physics measurements that will regard the polarized structure of the proton, the angular momentum of gluons, Cold Nuclear Matter phenomena and the physics at high x-Bjorken. All these are relevant for the search of particles Beyond Standard Model. The thesis work foresees periods at CERN for prototypes development, data taking, results presentation and discussion.
Trigger algorithms development for rare decays at LHCb Data analysis

P. De Simone

The upgrade of the LHCb experiment will allow to reach luminosities of the order of 2×1033 cm-2s-1 and beyond, with data readout frequencies of 40 MHz and a fully software trigger. This poses interesting perspectives for the search of rare decays like i.e. D0 → μ+μ and Ks → μ+μ, which are extremely sensitive to possible contributions beyond the Standard Model. The detection and unambiguous identification of muons is one of the fundamental aspects for the success of this experimental program. The conditions foreseen for the LHCb upgrade are challenging, due to the significant increase of the particle fluxes on the muon detector which represent mainly a background to reject at trigger level. The thesis work foresees the study and the development of novel and fast algorithms for the muon selection to be applied during the last phases of the present data taking with the aim to search for rare events with muons in the final state.

Investigation of Quark Gluon Plasma at LHCb Data analysis

P. Di Nezza

The Quantum Chromo Dynamics (QCD), one of the major fundamental theories of physics, shows still unresolved aspects. The realization in laboratory of the Quark Gluon Plasma allows to re-create matter in the conditions of the Primordial Universe opening the possibility to study QCD, its evolution and the processes of hadrons formation. LHCb is the most innovative detector for this kind of physics thanks to its acceptance, to the possibility to reconstruct particles with very low momentum transfer and the full Particle Identification capability. For the first time, it will be possible to access a kinematic region not accessible by the other LHC experiments, in particular in the field of heavy quarks, quarkonia and open flavor to perform pioneering measurements. Furthermore, for pA collisions, the measurements of gluon shadowing will be fundamental for the future colliders like the EIC. The thesis work foresees periods at CERN for data taking, discussion and presentation of the results.
Construction of a new tracking detector, based on the CGEM technology, for the BESIII experiment Instrumental/
Data analysis

M. Bertani

The BESIII experiment, installed at the BEPCII accelerator of the laboratory IHEP of Beijing, performs studies on charmed mesons, measurements of form factors of mesons and baryons with and without strageness, measurements in general of multihadronic production, and searches for new hadronic states. At LNF is under construction a new internal tracking system, based on the CGEM (Cylindrical Gas Electron Multiplier) technology, that during 2018 will substitute the internal drift chamber of the BESIII apparatus. The thesis work foresees a part of data analysis to study ψ(3686) meson decays together or in alternative to an instrumental part of work on the CGEM detector