Phillip Urquijo

15 October 2013
CHEP 2013

Abstract: The Belle II experiment is a future flavour factory experiment at the intensity frontier SuperKEKB e+e- collider, KEK Japan. Belle II is expected to go online in 2015, and collect a total of 50 ab-1 of data by 2022. The data will be used to study rare flavour phenomena in the decays of B- and D- mesons and tau-leptons, as well as heavy meson spectroscopy. Owing to the record breaking luminosity of SuperKEKB, L=8x10^35 cm-2s-1, and to the large number of detector channels, particularly in the silicon tracking detector (4 strip + 2 pixel layers) the data output rate is expected to rival that of the LHC experiments. In this presentation we will present the Belle II physics analysis model, designed to cope with both precision measurements, and searches for rare processes on this prodigious quantity of data. We will discuss how the new framework is being constructed to robustly use Grid computing, with common analysis tools, common data preparation tools, and a steering mechanism for automated reconstruction of particle cascades. At the core of the framework is a newly developed root based physics analysis data model, a layer for particle reconstruction and persistency. It will facilitate centralised computation of multitudes of particle decay channels for analysis groups. A key aspect for particle reconstruction at SuperKEKB will be the use of recoil techniques, which rely on precisely known initial beam energies, to study decays with neutrinos and multiple neutral particles in the final state. We will discuss how we are integrating various recoil techniques into the design of the analysis framework, and the particle persistency layer. We also discuss integration of other complex analysis tools, such as continuum suppression and tag vertexing for CP violation analyses. The analysis data model, and its optimisation for Grid facilities will be discussed. Finally the reconstruction capabilities of the framework will be shown, including Monte Carlo studies for the analysis of physics benchmark channel