Related papers: Software and Physics Simulation at Belle II

The Belle and Belle II experiments have collected a 1.4 ab$^{-1}$ sample of $e^+e^-$ collision data at centre-of-mass energies near the $\Upsilon (nS)$ resonances, of which 424 fb$^{-1}$ were collected at Belle II in Run1 (2019--2022). We…

We present recent results from the Belle II experiment related to quarkonium and charm physics. With data samples collected by Belle II during operation of the SuperKEKB collider above the $\Upsilon(4S)$ resonance, we study the processes…

We present the analysis of two-particle angular correlations using coordinate systems defined with the conventional beam axis and the event thrust axis, and propose the latter to be a useful representation for the correlation structure…

For the Belle II experiment at KEK (Tsukuba, Japan) the KEKB accelerator was upgraded to deliver a 40 times larger instantaneous luminosity than before, which requires an increased radiation hardness of the detector components. As the…

A series of data samples was collected with the Belle~II detector at the SuperKEKB collider from March 2019 to June 2022. We determine the integrated luminosities of these data samples using three distinct methodologies involving Bhabha…

We present preliminary results on the reconstruction of the $B^0\to J\mskip 1mu / \psi\mskip 2mu K^0_{\scriptscriptstyle L}$ decay, where $J\mskip 1mu / \psi\mskip 2mu\to\mu^+\mu^-$ or $e^+e^-$. Using a dataset corresponding to a luminosity…

A file repository for calculations of cross sections and kinematic distributions using Monte Carlo generators for high-energy collisions is discussed. The repository is used to facilitate effective preservation and archiving of data from…

We report on a search for a resonance $X$ decaying to a pair of muons in $e^{+}e^{-}\rightarrow \mu^+ \mu^- X$ events in the 0.212-9.000 GeV/$c^{2}$ mass range, using 178 fb$^{-1}$ of data collected by the BelleII experiment at the…

We report on the first Belle II measurement of the branching fraction ($\mathcal{B}$) and longitudinal polarization fraction ($f_L$) of $B^+\to \rho^+\rho^0$ decays. We reconstruct $B^+\to \rho^+(\to \pi^+\pi^0(\to \gamma\gamma))\rho^0(\to…

Using the Belle data on the decay $\Upsilon(10860)\to \Upsilon(1S)f_0(980)\to\Upsilon(1S)\pi^+\pi^-$, we estimate the fraction of the process $\Upsilon(10860)\to\Upsilon(1S)f_0(980)\to \Upsilon(1S)\eta\pi^0$, caused by the mixing of…

The Silicon Vertex Detector (SVD), with its four double-sided silicon strip sensor layers, is one of the two vertex sub-detectors of Belle II operating at SuperKEKB collider (KEK, Japan). Since 2019 and the start of the data taking, the SVD…

Decays of $B$ mesons involving the transition of a $b$ quark into an $s$ quark are good probes of physics beyond the standard model. Such decays are studied at the Belle II experiment, a detector located along the SuperKEKB…

Hyper-Kamiokande (Hyper-K) succeeds the very successful Super-K experiment and will consist of a large detector filled with 260~kton purified water and equipped with 40\% photo-coverage. Physics program of Hyper-K is broad, covering from…

The Silicon Vertex Detector of Belle II is a state-of-the-art tracking and vertexing system based on double-sided silicon strip sensors, designed and fabricated by a large international collaboration in the period 2012--2018. Since 2019 it…

Belle II has recently reported the new measurement ${\cal B}(B^+\to K^+\nu\bar\nu)=(2.3\pm0.7)\times 10^{-5}$ \cite{Belle-II:2023esi} which is two times larger than their previous result (although consistent within errors) and about…

We present the result of a search for the charged-lepton-flavor violating decays $\tau^- \rightarrow e^\mp \ell^\pm \ell^-$, where $\ell$ is a muon or an electron, using a data sample with an integrated luminosity of 428 fb$^{-1}$ recorded…

We present a track-finding algorithm for the Belle II experiment that specifically targets so-called kinks: signatures of charged particles decaying or scattering in-flight in the detector material, resulting in a sudden and significant…

Precision studies of flavour-changing processes involving quarks and leptons provide a number of ways to improve knowledge of the Standard Model and search for physics beyond it. There are excellent short- and mid-term prospects for…

In the framework of detector development, Monte Carlo simulations play a key role in the evaluation of the expected performance and the full understanding of the behavior in beam conditions. In particular, a software which simulates the…

We report on the construction, operation, and performance of the Time-of-Propagation detector with imaging used for the Belle II experiment running at the Super-KEKB $e^+e^-$ collider. This detector is located in the central barrel region…