Related papers: New Particles from Belle

We measure the branching fractions of $B^{0} \to J/\psi \eta^{(}{}'{}^{)}$ decays with the complete Belle data sample of $772 \times 10^{6}$ $B\bar{B}$ events collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB…

The process $e^+e^- \to \gamma\chi_{cJ}$ ($J$=1, 2) is studied via initial state radiation using 980 fb$^{-1}$ of data at and around the $\Upsilon(nS)$ ($n$=1, 2, 3, 4, 5) resonances collected with the Belle detector at the KEKB…

We present a search for the decay $X(3872) \to \pi^+\pi^-\pi^0$ in the $(772\pm11)\times10^6$ $\Upsilon(4S)\to B \bar B$ data sample collected at the Belle detector, where the $X(3872)$ is produced in $B^{\pm}\to K^{\pm}X(3872)$ and…

Using a data sample of 980 fb$^{-1}$ collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider, we study for the first time the singly Cabibbo-suppressed decays $\Omega^0_c\to\Xi^{-}\pi^{+}$ and $\Omega^-K^+$ and the…

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…

Using the large data sample accumulated by the Belle experiment at KEKB asymmetry energy $e^+e^-$ Collider, we report the preliminary measurements of the branching fractions of the radiative decays $D^0 \rightarrow V\gamma$, where $V$ =…

Using 58 million $J/\psi$ decays, we have investigated the $p \bar{p}$ invariant mass spectrum in the radiative decay $J/\psi \to \gamma p \bar{p}$ and observe a prominent structure with mass near $2m_p$. Fitting with an S-wave…

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 report a measurement of the inclusive electron energy spectrum for charmed semileptonic decays of B mesons in a 140 fb^-1 data sample collected on the Upsilon(4S) resonance, with the Belle detector at the KEKB asymmetric energy e^+ e^-…

We present a search for the B-> pi e^+ e^- and B-> pi \mu^+ \mu^- decays, with a data sample of 657 million BBbar pairs collected with the Belle detector at the KEKB $e^+e^-$ collider. Signal events are reconstructed from a charged or a…

We report the first measurement of the charm-mixing parameter $y_{CP}$ in $D^{0}$ decays to the $CP$-odd final state $K^{0}_{S}\omega$. The study uses the full Belle $e^{+}e^-$ annihilation data sample of $976\rm~ fb^{-1}$ taken at or near…

Using the data sample of 980 fb$^{-1}$ collected with the Belle detector operating at the KEKB asymmetric-energy $e^+e^-$ collider, we present the results of an investigation of the $\Lambda\pi^+$ and $\Lambda\pi^-$ invariant mass…

The $b \rightarrow s \gamma$, $b \rightarrow d \gamma$ and $b \rightarrow s \ell^+ \ell^-$ processes are allowed at higher order via the electroweak loop or box diagrams in the Standard model. It is sensitive probe to search for new physics…

We report an observation of the decay B^\pm -> \phi \phi K^\pm and evidence for B^0 -> \phi \phi K^0. These results are based on a 414 fb^{-1} data sample collected with the Belle detector at the KEKB asymmetric-energy e^+e^- collider…

Using the data sample of 10.5 fb-1 collected by the Belle detector, we searched for two-body charmless decays involving vector mesons. The clear signal signature of B+ -> phi K+ is seen and its branching fraction is measured to be…

We report results based on a 1.86 fb$^{-1}$ data sample collected on the $\Upsilon$(5S) resonance by the Belle detector at the KEKB asymmetric energy $e^+ e^-$ collider. The inclusive production of $D_s$, $D^0$ and $J/\psi$ mesons at the…

We present a search for the dark photon $A^{\prime}$ in the $B^0 \to A^{\prime} A^{\prime}$ decays, where $A^{\prime}$ subsequently decays to $e^+ e^-$, $\mu^+ \mu^-$, and $\pi^+ \pi^-$. The search is performed by analyzing $772 \times…

The Belle and Belle II experiments have collected an 1.6 ab$^{-1}$ sample of $e^+e^-$ collision data at center-of-mass energies near the $\Upsilon(nS)$ resonances. In particular, the Belle II experiment collected a 19.2 fb$^{-1}$ sample of…

We search for the doubly charmed baryonic decay $\bar{B}^0\to\Lambda_c^+\bar{\Lambda}_c^-$, in a data sample of $520\times10^6$ $B{\bar B}$ events accumulated at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric…

We report a study of $B \to J/\psi(\ell^{+}\ell^{-})K$ decays, where $\ell$ represents an electron or a muon, using $e^{+}e^{-}$ collisions at the $\Upsilon(4S)$ resonance. The data were collected by the Belle II experiment at the SuperKEKB…