Parts | Days | Selection | Search | Updates | Downloads | Help
T: Fachverband Teilchenphysik
T 104: Flavor VIII
T 104.4: Talk
Thursday, March 23, 2023, 16:35–16:50, HSZ/0304
Untagged analysis of B → π ℓ νℓ and B → ρ ℓ νℓ and extraction of |Vub| at Belle II — Florian Bernlochner, Jochen Dingfelder, •Svenja Granderath, and Peter Lewis for the Belle II collaboration — Physikalisches Institut der Rheinischen Friedrich-Wilhelms-Universität Bonn
One of the puzzles of current research in flavor physics is the persisting discrepancy between the results of exclusive and inclusive measurements of the CKM matrix element |Vub|. The charmless semileptonic decays B → π ℓ νℓ and B → ρ ℓ νℓ belong to the most accessible and powerful channels for determining |Vub| in exclusive modes. Using data from the Belle II experiment, new precision measurements of |Vub| can be performed. In preparation for this, an untagged measurement method for simultaneously extracting B → π ℓ νℓ and B → ρ ℓ νℓ events is developed. An untagged measurement allows for sufficiently large samples of these rare decays already with the current Belle II dataset. In order to increase the signal purity, boosted decision trees are employed to suppress continuum and BB backgrounds. Once the signal events are extracted, |Vub| is determined using the measured partial branching fractions in combination with theory predictions of hadronic form factors. This talk will present the current status of the analysis and |Vub| extraction.