非表示:
キーワード:
Belle II
要旨:
This thesis searches for "tau to lepton + invisible". We search with 62.8 fb-1 of Belle II data and find no evidence for this decay. We determine an upper limit in the range of 1‰ to 1% for the ratio of branching ratios. This thesis contributed to Belle II performance studies. We develop and test new tau-rest frame estimation methods and find that one (the GKK method) shows perspectives to substantially enhance the statistical precision of the tau mass measurement.
