In the big bang, matter and antimatter should have been created in equal amounts. But why is the universe today filled almost only with matter? Physicists attribute the different behaviour of matter and antimatter to the violation of the so-called CP symmetry. This fundamental symmetry of nature states that laws of physics should not change when a particle is interchanged with its antiparticle and the signs of all its spatial coordinates are flipped. Still, the extent of the observed CP violation is not sufficient to explain the actual excess of matter in the universe. The Belle II experiment in Japan aims to solve this great mystery of particle physics, together with many other unsolved issues...

The Belle II detector is located in the collision area of the SuperKEKB e+e- collider at the KEK laboratory in Tsukuba, Japan.  The Belle II experiment collected in the last years 424 fb^-1of integrated luminosity usable for physics. The goal is to reach 50 ab^-1 of integrated luminosity within 2030. The SuperKEKB accelerator is now in long shutdown until end 2023 for the accelerator components and the Belle II detector upgrades.

The Belle II collaboration consists of over 1160 physicists and engineers from 130 institutions in 27 countries. Italy participates in Belle II, and in particular the Torino group with involvement in both hardware, software, computing and analysis.

The Italian participation to Belle II is funded by INFN (Istituto Nazionale di Fisica Nucleare). 

The Belle II  Torino research activities are focused on:

• Maintaining the laser calibration system for the Time-Of-Propagation detector (TOP), aimed at performing high precision particle identification by means of Cherenkov light. This involves both hardare and software activities, including calibration and development of particle identification algorithms
• Perform physics studies involving quarkonium spectroscopy, new physics in rare decays of B, D mesons and tau lepton, and search for Dark Matter in the light sector
• Develope software algorithms for charged particle tracking, in order to achieve high resolution and efficiency
• Developement of algorithm for the reconstruction of anti-neutrons
• Implement a cloud computing infrastructure for the distributed computing of the experiment

• Cherenkov detector and Particle Identification: University of Padua,  University of Hawaii
• Charged Particle Tracking: University of Pisa
• Physics Studies: - Technical University of Munich - University of Mississippi

Spectroscopy, quarkonium, e+ e- colliders, tracking, particle identification, TOP, Cherenkov detectors