Relazione sulle ATTIVITÀ SVOLTE a cura del candidato Corso di dottorato in Fisica - XXXII ciclo
ATTIVITÀ FORMATIVE / Educational ACTIVITIES
I anno di corso / I year (anno accademico / academic year 2016-2017) DENOMINAZI ONE DEL CORSO / PhD Programme DURATA / DURATIO N (in ore / in hours) SEDE / LOCATION (indicare Università o altra sede di svolgimento / indicate the university location or other location) DOCENTE / PROFESSOR (nome e cognome / name and family name) VOTAZIO NE / FINAL MARK GIUDIZIO / FINAL ASSESS MENT LINGUA UTILIZZA TA LANGUAG E (italiano, inglese, altra lingua / Italian, English or other languages) Corsi del dottorato frequentati/ Attended PHd Programmes Corsi di Fisica Sperimentale delle alte energie 40 ore Sezione INFN di Pisa, Scuola Normale Superiore di Pisa M. Sozzi, G. Rolandi, S. Leone, G. Batignani, M. Morello. Ottimo Inglese Corso di Analisi Statistica dei dati 40 ore Sezione INFN di Pisa
G. Punzi Ottimo Inglese
Corso di Scrittura Scientifica 6 ore Sezione di Pisa INFN S. Shore - Inglese Altri corsi/ Other Programmes Onde gravitazionali 40 ore Dipartiment o di Fisica E.Fermi, Largo Bruno Pontecorvo, 3
II anno di corso / II year (anno accademico / academic year 2017-2018) Seminari di ricerca/Research Seminars (argomento e ore di svolgimento / topics and number of hours attended )
Pisa School on Future Colliders, September 17-21, 2018 - University and INFN of Pisa, with the participation of Scuola Normale di Pisa (Pisa); ~35 ore (5 giorni di scuola) sulle prospettive nel medio e lungo termine della fisica delle particelle concernente le diverse proposte per acceleratori futuri.
Esperienze di ricerca presso altre strutture / Research experience in other institutions Trimestre di ricerca al laboratorio di KEK, Tsukuba, presso l’esperiment o Belle II.
I spent a 3-month term at KEK laboratory for the
commissioning of the Belle II detector during the 2018 pilot run, being involved in the Silicon Vertex Detector (SVD) commissioning and also performing experimental shifts for the Belle II Commissioning Group (BCG). As BCG member, my duty consisted in being the liaison between the machine experts and the Belle II detector during data taking. In addition, my contribution to the performance and validation studies on first collision data regarded the development of the software used to reconstruct SVD data, specifically for what concerns the calibration framework and the studies to assess the good quality of the first data recorded by the SVD.
Attività o borse all’estero/Trainin g or Scholarship abroad Borsa di studio Fondazione Angelo Della Riccia per periodo di ricerca al’estero.
Ha finanziato l’attività di ricerca di cui sopra.
III anno di corso / III year (anno accademico / academic year 2018-2019) Esperienze di ricerca presso altre strutture / Research experience in other institutions Trimestre di ricerca al laboratorio di KEK, Tsukuba, presso l’esperimento Belle II.
For a 3-month term I have been involved in the resumed operation at the SuperKEKB accelerator and Belle II detector, at KEK laboratory, after the summer-autumn shutdown at the end of Phase 2 operations. For this new commissioning stage, Phase 3, the Belle II detector is installed in its final
configuration with the full vertex detector in place and started taking physics data in March 2019. My involvement in the operations regarded both the accelerator and the detector side. As a Belle II Commissioning Group member, I had to take shifts in the accelerator control room, being the liaison
between the machine experts and the Belle II detector. Concerning the detector commissioning, my activity focused on SVD performance studies and track finding efficiency studies on early Phase 3 data.
Research project for doctoral thesis
The Standard Model (SM) of particle physics has been proven by many experimental results to be a predictive theory and currently the best known description of the fundamental constituents of nature and their interactions. However, it cannot account for some known phenomena, such as the existence of dark matter, established by many astrophysical and cosmological observations which provide the measurement for its relic abundance. Dark matter (DM) is among the most compelling issues for new
physics beyond the SM, but remains a complicated mystery to solve, since almost nothing is known about its origin and its nature. Therefore it deserves to be searched for with all available experimental tools.
The dark matter puzzle can be addressed by assuming a thermal production in the early universe. In most of the theoretical frameworks, to account for the measured relic abundance and avoid DM overproduction, a new mediator that can couple to DM and SM particles is required to enhance the DM annihilation rate. A simple solution to extend the SM and account for this additional mediator is by considering a dark gauge $U(1)_D$ invariance which is associated with a new massive boson that can connect the SM particles to the unknown constituents of a new hidden sector.
The work presented in this thesis concerns the first searches for the invisible decay of a Z’ boson in the process e+e- → μ+μ- Z’ and of a lepton-flavor-violating Z’ in e+e- → e+μ
-Z’ on the data set collected in 2018 during the first physics run of the Belle II detector, installed at the asymmetric energy electron-positron collider SuperKEKB, at KEK Laboratory (Tsukuba, Japan). No excess of events was found, and a 90% credibility level upper limits on the cross sections of these processes. The former is also translated, in the framework of an Lμ-LLτ theory, into upper limits on the Z’ coupling
constant at the level of 5x10-2 – 1 for M
Z’ ≤ 6 GeV/c2.
Moreover, this thesis work assesses the capability to provide competitive constraints on the Lμ-LLτ model with the upcoming Belle II 2019 data, that could solve both the
known tension in the SM regarding the anomalous magnetic moment of the muon and one of the most compelling issue for modern particle physics such as dark matter.
Partecipazione a workshop nazionali e internazionali:
1) VII International Course: Detectors and Electronics for High Energy Physics,
Astrophysics, Space Applications and Medical Physics (Laboratori Nazionali Legnaro, INFN) – Aprile 2017, 40 ore. “The Course is of interest for PhD students and postgraduates, young scientists, technical personnel and young technologists, operating in the fields of High Energy Physics, Astrophysics,, Space Science and Technologies, Medical Physics in Universities, Research Institutes and Industries who have interest to deepening the following thematics:
a) semiconductor detectors, electronic devices and systems and their application for High Energy Physics, Astrophysics, Space Science and Technologies and Medical Physics;
b) radiation effects in semiconductor detectors, optical and electronic devices and components;
c) Italian and European irradiation facilities for interdisciplinary applications. 2) Workshop on hadronic vacuum polarization contributions to muon g-2 - KEK, High
Energy Accelerator Research Organization (Tsukuba, Japan), Febbraio 2018. Seminario di 3 giorni sullo stato teorico e sperimentale del momento magnetico anomale del muone.
3) KMI School on Dark Matter - Kobayashi-Maskawa Institute, University of Nagoya,
Dark Matter, sui risultati di ricerche dirette e indirette e sulle prospettive di misura agli acceleratori.
4) VI KEK Flavor Factory Workshop - KEK, High Energy Accelerator Research Organization (Tsukuba, Japan). Febbraio 2019. Seminario di 3 giorni
5) Belle II VXD open workshop – CERN (Geneva), Luglio 8-10, 2019.
Contributo a conferenze nazionali e internazionali:
1. November 2022, 2019 “Light Dark Matter at Accelerators 2019 (LDMA19)” -Fondazione Querini Stampalia, Venice.
Oral presentation: Missing mass searches at B-Factories, BaBar and Belle II first results and prospects.
2. May 13-17, 2019 - “QWG2019, The 13th International workshop on Heavy Quarkonium”- Cavallerizza Reale, Turin.
Oral presentation: Dark Sector Searches at B-factories.
3. October 1-3, 2018 - “XIII B-physics workshop”- Le Pharo, Marseille. Oral presentation: Dark Sector Searches at Belle II
4. July 4-11, 2018 - “ICHEP2018, XXXIX International Conference on High Energy physics” - COEX, Seoul.
Oral presentation: Search for the B meson decay to four baryons.
5. April 16-20, 2018 - “DIS2018, International Workshop on Deep Inelastic Scattering and Related Subject” -Kobe, Japan.
Oral presentation: Recent QCD results from BaBar, combined talk.
6. September 25-29, 2017 - “HADRON2017, XVII International Conference on Hadron Spectroscopy and Structure” - Salamanca, Spain.
Oral presentation: Search for B-meson decays to four baryons at BaBar. 7. July 5-12, 2017- “EPS Conference on High Energy Physics”, Venice.
Oral presentation: Recent QCD results at Babar, Poster Session: Search for B-meson decays to four baryons at Babar.
8. April 2017- “XVI Incontri di Fisica delle Alte Energie, IFAE”- Univ. degli Studi di Trieste.
Poster Session: Search for B-meson decays to four baryons at BaBar and future prospects at Belle II.
