Maximilian Welsch ; Florian Bernlochner

20 July 2020

Abstract: We present a measurement of the first six hadronic mass moments in semi-leptonic $B\rightarrow X_c \ell \nu$ decays. The measurement is using the Belle~II data-set recorded at the $\Upsilon(4\mathrm{S}$ resonance in 2019 and 2020 (March-July), corresponding to an integrated luminosity of \SI{34.58}{fb^{-1}}. The decay $\Upsilon(4\mathrm{S})\rightarrow B\overline{B}$ is reconstructed by applying the hadronic tagging algorithm provided by the Full Event Interpretation to fully reconstruct on \PB meson, while the second $B$ meson is reconstructed inclusively by selecting a high-momentum lepton. The $X$-system is identified by the remaining reconstructed tracks and cluster in the electromagnetic calorimeter. We report preliminary results for $M_X^n$ with $n=1,\dots,6$, measured as a function of a lower cut on the lepton momentum in the signal $B$ rest frame.