Speaker
Description
At Belle II, $B$ mesons are produced in pairs nearly at rest. The Full Event Interpretation (FEI), a machine-learning based background-suppression method, reconstructs one of the $B$ mesons in a well-known decay mode (the tag side). The remaining particles in the event are then used to reconstruct the signal $B$ meson.
The Semileptonic FEI uses a hierarchical decay-chain reconstruction in which intermediate particle candidates are ranked with gradient-boosted decision trees, allowing reconstruction of tag-side Semileptonic decays such as $B \rightarrow D^*\ell\nu$. In this study, we extend the scope of the tag-side reconstruction by adopting tagging modes that tolerate missing soft photons and slow pions from $D^{*} \rightarrow D\, \pi / \gamma$ decays. The performance of this extended SL tag is evaluated using Monte Carlo simulation and $365\ \mathrm{fb}^{-1}$ of Belle II data, with the well-known benchmark decays $B \to D^{(*)}\ell\nu$ used for comparison. This work reports a sensitivity estimate of the extended Semileptonic tagging algorithm and provides a comparison to the conventional FEI tag at Belle II.
| Your current academic level | MSc student |
|---|---|
| Your email address | xp@uvic.ca |
| Affiliation | University of Victoria |
| Supervisor name | Prof. Bob Kowalewski |
| Supervisor email | kowalews@uvic.ca |