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Digital archive of theses discussed at the University of Pisa

 

Thesis etd-09232021-172010


Thesis type
Tesi di laurea magistrale
Author
MASSACCESI, LUDOVICO
URN
etd-09232021-172010
Thesis title
Performance study of the SVD detector of Belle II and future upgrades
Department
FISICA
Course of study
FISICA
Supervisors
relatore Prof. Forti, Francesco
Keywords
  • B-factory
  • Belle II
  • CMOS sensors
  • D0
  • Flavour physics
  • Silicon Vertex Detector
Graduation session start date
25/10/2021
Availability
None
Summary
Belle II is a general-purpose particle detector located at the interaction point of the SuperKEKB B-factory collider, and managed by an international collaboration. The experiment will focus on the precision measurement of the decays of bottom and charmed mesons, and tau leptons, and on the search for rare or forbidden decay processes that may be evidence of effects beyond the Standard Model.
The VerteX Detector (VXD) of Belle II is designed to accurately reconstruct the four-momenta and vertices of all charged particles. It is made of the innermost PiXel Detector (PXD), with DEPFET-based sensors, and of the outermost Silicon Vertex Detector (SVD), with double-sided silicon strip detectors.
This thesis presents a study of the radiation damage in the SVD sensors, and discusses a possible upgraded vertex detector (VTX), based on monolithic CMOS pixel sensors, for operation at high luminosity, on which physics benchmarking of some key channels has been performed.
A method to estimate the total integrated dose in SVD was developed, which introduces several improvements and bias corrections with respect to the previous estimates. Algorithms to monitor changes of sensor parameters that are sensitive to radiation damage were also developed.
A physics benchmark of VTX, based on simulations of B0 -> D* mu nu -> (D0 pi) mu nu events with D0 -> K pi or -> K pi pi pi, is also presented, showing improvements in key variables such as tracking efficiency and vertex resolution.
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