000002681 001__ 2681
000002681 005__ 20210921072038.0
000002681 037__ $$aBELLE2-CONF-PROC-2021-020
000002681 041__ $$aeng
000002681 100__ $$aYoungmin Yook
000002681 245__ $$aRediscovery of $X(3872)$ at Belle II Experiment
000002681 260__ $$a$$c2021-09-12
000002681 300__ $$a7
000002681 520__ $$aThe Belle II experiment has accumulated data corresponding to $89.99~{\rm fb}^{-1}$ integrated luminosity in the past 2 years, and is performing very good. Waiting that the full planned data set will be recorded $(50~{\rm ab}^{-1})$, which will allow search for rare processes and will have a tremendous impact in the spectroscopy field, the Phase 3 data set allows to already perform analysis with high precision.   We present here the analysis of $B\to K J/\psi \pi^+ \pi^-$ and $B\to K\psi(2S)$: in the former for the first time the evidence for the $X(3872)\to J/\psi \pi^+\pi^-$ has been found at Belle II, which is consistent with the observation at Belle of the same resonant state, performed in 2003. The re-discovery of the $X(3872)$ based on the early Phase3 data includes the efficiency and resolution study, calibration with $B\to K\psi(2S)$, and background check. When higher statistics will be available, Belle II is planning the even more interesting analysis of $B\to D\bar{D}\pi^0K$, and search for $X(3872)\to D\bar{D}\pi^0$.
000002681 6531_ $$aX(3872)
000002681 6531_ $$aRediscovery
000002681 6531_ $$aHADRON2020
000002681 8560_ $$fyook@ihep.ac.cn
000002681 8564_ $$uhttps://docs.belle2.org/record/2681/files/BELLE2-CONF-PROC-2021-020.pdf
000002681 8564_ $$uhttps://docs.belle2.org/record/2681/files/BELLE2-CONF-PROC-2021-020-r1.pdf
000002681 8564_ $$uhttps://docs.belle2.org/record/2681/files/BELLE2-CONF-PROC-2021-020-r2.pdf