Related papers: The Belle II Physics Book
The $b\to s(d)$ quark-level transitions are flavor-changing neutral current processes, which are not allowed at tree level in the standard model. These processes are very rare and constitute a potential probe for new physics. Belle II at…
The Belle experiment, running at the KEKB e+e- asymmetric energy collider during the first decade of the century, achieved its original objective of measuring precisely differences between particles and anti-particles in the B system. After…
The Belle II experiment is under construction at the KEK laboratory in Japan. Belle II will study e+e- collisions at or near the Upsilon(4S) resonance with the goal of collecting 50 ab-1 of data, which is a large increase over that recorded…
We report a measurement of the branching fraction for the leptonic decay $B^+\to\mu^+\nu_\mu$. This work presents the first $B^+\to\mu^+\nu_\mu$ result using Belle~II data, an updated Belle measurement that supersedes the previous result,…
The Belle II Collaboration comprises over 1000 international high energy physicists, who investigate the properties of $b$-quarks and other particles at the luminosity frontier. In order to achieve our aim of a successful physics program,…
The Belle experiment has given a substantial contribution in the field of heavy quarkonia. Several new states were announced by Belle for the first time, in both charmonium and bottomonium spectrum, or the confirmation from Belle…
The Belle detector at the KEKB electron-positron collider has collected approximately 800 million Upsilon(4S) events in its decade of operation. The KEKB group has proposed Super-KEKB, an upgrade of KEKB to increase the luminosity by two…
The Belle detector operated at KEKb B-factory in 1999-2010 was one of the most remarkable experiments in the field of elementary particle physics of the last decades. The Belle successor, Belle II collaboration, is aimed to operate the…
The high design luminosity of the SuperKEKB electron-positron collider is expected to result in challenging levels of beam-induced backgrounds in the interaction region. Properly simulating and mitigating these backgrounds is critical to…
The Belle II experiment, located at the SuperKEKB collider at the high-energy research facility KEK in Tsukuba, Japan, started operation in 2018. Compared to the predecessor experiment Belle, Belle II plans to increase the peak luminosity…
We utilize a sample of 34.6 fb$^{-1}$, collected by the Belle II experiment at the SuperKEKB asymmetric energy $e^+e^-$ collider, to search for the $B^+ \to \phi K^+$, $B^+ \to \phi K^{*+}$, $B^0 \to \phi K^0_S$, and $B^0 \to \phi K^{*0}$…
Quarkonium is the bound state of a heavy quark and its anti-quark counterpart. The study of this system has experienced a renaissance thanks to results from e+e- collider experiments, including discoveries of long-predicted conventional…
Belle II is a major upgrade of the Belle experiment and will operate at the $B$-factory SuperKEKB in Japan. Here we discuss the expected sensitivity of Belle II for $D^0 - \bar{D}^0$ mixing and $CP$ violation measurements in the charm…
We report on a Belle II measurement of the branching fraction ($\mathcal{B}$), longitudinal polarization fraction ($f_L$), and CP asymmetry ($\mathcal{A}_{CP}$) of $B^+\to \rho^+\rho^0$ decays. We reconstruct $B^+\to \rho^+(\to…
We report on the reconstruction of various charmless $B$ decays from electron-positron collisions at the energy corresponding to the $\Upsilon(4S)$ resonance collected with the Belle II detector at the SuperKEKB collider. We use simulation…
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…
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…
The Belle II experiment is a high-energy physics experiment at the SuperKEKB electron-positron collider. Using Belle II data, high precision measurement of rare decays and CP-violation in heavy quarks and leptons can be performed to probe…
The investigation of $B$ meson decays to charmed and charmless hadronic final states is a keystone of the Belle II program. Analyses of such decays provide reliable and experimentally precise constraints on the weak interactions of quarks.…
We report updated measurements of branching fractions ($\mathcal{B}$) and CP-violating charge asymmetries ($\mathcal{A_{\rm CP}}$) for charmless $B$ decays at Belle II, which operates on or near the $\Upsilon$(4S) resonance at the SuperKEKB…