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تسجيل مستخدم جديدOnline Data Reduction for the Belle II Experiment using DATCON
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The new Belle II experiment at the asymmetric $e^+ e^-$ accelerator SuperKEKB at KEK in Japan is designed to deliver a peak luminosity of $8times10^{35}text{cm}^{-2}text{s}^{-1}$. To perform high-precision track reconstruction, e.g. for measurements of time-dependent CP-violating decays and secondary vertices, the Belle II detector is equipped with a highly segmented pixel detector (PXD). The high instantaneous luminosity and short bunch crossing times result in a large stream of data in the PXD, which needs to be significantly reduced for offline storage. The data reduction is performed using an FPGA-based Data Acquisition Tracking and Concentrator Online Node (DATCON), which uses information from the Belle II silicon strip vertex detector (SVD) surrounding the PXD to carry out online track reconstruction, extrapolation to the PXD, and Region of Interest (ROI) determination on the PXD. The data stream is reduced by a factor of ten with an ROI finding efficiency of >90% for PXD hits inside the ROI down to 50 MeV in $p_text{T}$ of the stable particles. We will present the current status of the implementation of the track reconstruction using Hough transformations, and the results obtained for simulated Upsilon(4S) $rightarrow , Bbar{B}$ events.
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We report on the first calibration of the standard Belle II $B$-flavor tagger using the full data set collected at the $Upsilon(4{rm S})$ resonance in 2019 with the Belle II detector at the SuperKEKB collider, corresponding to 8.7 fb$^{-1}$ of integr
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We describe the conversion of simulated and recorded data by the Belle experiment to the Belle~II format with the software package texttt{b2bii}. It is part of the Belle~II Analysis Software Framework. This allows the validation of the analysis softw
are and the improvement of analyses based on the recorded Belle dataset using newly developed analysis tools.
From April to July 2018, a data sample at the peak energy of the $Upsilon(4S)$ resonance was collected with the Belle~II detector at the SuperKEKB electron-positron collider. This is the first data sample of the Belle~II experiment. Using Bhabha and
digamma events, we measure the integrated luminosity of the data sample to be ($496.3 pm 0.3 pm 3.0$)~pb$^{-1}$, where the first uncertainty is statistical and the second is systematic. This work provides a basis for future luminosity measurements at Belle~II.
We present an FPGA-based online data reduction system for the pixel detector of the future Belle II experiment. The occupancy of the pixel detector is estimated at 3 %. This corresponds to a data output rate of more than 20 GB/s after zero suppressio
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