000002943 001__ 2943
000002943 005__ 20220324123741.0
000002943 037__ $$aBELLE2-MTHESIS-2022-005
000002943 041__ $$aeng
000002943 100__ $$aValeria Fioroni
000002943 245__ $$aStudy of charmless B → η′K decays with the Belle II experiment
000002943 260__ $$aPadova$$bDipartimento di Fisica e Astronomia “Galileo Galilei”$$c2021
000002943 300__ $$amult. p
000002943 500__ $$aPresented on 13 12 2021
000002943 502__ $$aMSc$$bPadova, Padova$$c2021
000002943 520__ $$aThe study of penguin-dominated B0 → η′K0S decays provides a good test of the Standard Model, since the CP violation measurement in this mode is sensitive to the presence of new physics effects in the loop. In this work, a precise description of the signal extraction for both charged and neutral B → η′K decays is presented, focusing on the suppression of the main background component: the continuum. A FastBDT classifier is trained to separate continuum and signal candidates, using variables related to the event topology. Furthermore, a study on multivariate Monte Carlo reweighting has been performed, in order to reduce the impact of the Monte Carlo mismodelling of the continuum suppression variables on the systematic uncertainty. From the measured signal yield, a branching fraction measurement has been performed, obtaining results consistent with world averages. Finally, a study on the signal ∆t resolution function is presented.
000002943 700__ $$aStefano Lacaprara$$edir.
000002943 8560_ $$fstefano.lacaprara@pd.infn.it
000002943 8564_ $$uhttps://docs.belle2.org/record/2943/files/BELLE2-MTHESIS-2022-005.pdf
000002943 980__ $$aTHESIS