ACP Seminar (Astronomy - Cosmology - Particle Physics)

Speaker: Ryosuke Itoh (KEK)
Title: Search for New Physics at Belle II by Global Fit
Date (JST): Wed, Apr 17, 2013, 13:30 - 15:00
Place: Seminar Room A
Related File: 885.pdf
Abstract: The signature of New Physics (NP) beyond Standard Model (SM) has not yet been observed in spite of the extensive search by the LHC experiments. There is a possibility that the energy scale of NP is more than 10TeV, and the indirect search by the flavor factory becomes more important which does not have a limitation in the search energy.

The Belle II experiment, a new generation B factory experiment at KEK, is now being prepared to fulfill the indirect search. A lot of measurements in B/D meson and tau particle decays sensitive to NP are examined in the experiment for the purpose. However, most of such individual decays are "rare" decays and it might be difficult to acquire enough statistics to conclude the existence of NP by the single measurement alone.

If NP exists, the theory with the NP can predict its effect in various decay modes. By performing a simultaneous analysis for the measurements obtained in such decay modes, the existence of NP can be searched for more efficiently with less accumulation of statistics.

For the simultaneous analysis, the use of global fit technique is considered to be promising. The technique is well known to be used in the determination of the unitarity triangle by combining various measurements (CKM fit), and its result established the CP violation in B meson decays bringing Novel Prize to Profs. Kobayashi and Maskawa.

In this seminar, the application of the global fit technique for the NP search in Belle II is discussed together with the detail of the CKM fit. In addition, the possibility to extend the global analysis to include other flavor factory results such as LFV and EDM measurements is also covered.