A. Garmash

Test of lepton flavor universality with $B ˉ \to D^{()} τ^{-} ν ˉ_{τ}$ and $B ˉ \to D^{()} ℓ^{-} ν ˉ_{ℓ}$ decays at Belle II

Belle II Collaboration, M. Abumusabh, I. Adachi +494

We test lepton flavor universality with a measurement of the branching-fraction ratios $R(D^{(*)}) \equiv \mathcal{B}(\bar{B} \rightarrow D^{(*)} τ^{-} \barν_τ)/\mathcal{B}(\bar{B}…

Search for the lepton-flavor-violating decay $τ^{\pm} \to μ^{\pm} γ$ at Belle II

Belle II Collaboration, M. Abumusabh, I. Adachi +466

We present a search for the lepton-flavor-violating decay $τ^{\pm} \to μ^{\pm} γ$ using a data sample that corresponds to an integrated luminosity of 428 fb $^{- 1}$ recorded by the Bel…

Search for axion-like particles decaying to two photons at Belle II

Belle II Collaboration, M. Abumusabh, I. Adachi +450

Axion-like particles (ALPs) are predicted in many extensions of the Standard Model and provide a well-motivated portal between visible and hidden sectors through their coupling to…

First measurement of the masses of the $Υ_{1} (1 D)$ and $Υ_{3} (1 D)$ states and the energy dependence of the cross sections for $e^{+} e^{-} \to Υ_{J} (1 D) η$ and $e^{+} e^{-} \to Υ_{J} (1 D) π^{+} π^{-}$

Belle, Belle II Collaborations, : +398

We study the processes $e^{+} e^{-} \to Υ_{J} (1 D) η$ and $e^{+} e^{-} \to Υ_{J} (1 D) π^{+} π^{-}$ at center-of-mass energies $s$ =(10.73 -- 11.02) GeV using a $142.5 fb^{- 1}$ data sample, in…

Search for $h_{b} (2 P) \to γ χ_{b J} (1 P)$ at $s = 10.860$ GeV

Belle Collaboration, A. Boschetti, R. Mussa +140

In the bottomonium sector, the hindered magnetic dipole (M1) transitions between P-wave states $h_{b} (2 P) \to χ_{b J} (1 P) γ$ , $J = 0, 1, 2$ , are expected to be severely su…

hep-ex2024★ 2 cited

Search for charmed baryons in the $Λ_{c}^{+} η$ system and measurement of the branching fractions of $Λ_{c} (2880)^{+}$ and $Λ_{c} (2940)^{+}$ decaying to $Λ_{c}^{+} η$ and $p D^{0}$ relative to $Σ_{c} (2455) π$

Belle Collaboration, S. X. Li, C. P. Shen +125

We search for excited charmed baryons in the $Λ_{c}^{+} η$ system using a data sample corresponding to an integrated luminosity of 980 $f b^{- 1}$ . The data were collected by the Bell…

Evidence of $h_{b} (2P) \to Υ (1S) η$ decay and search for $h_{b} (1P,2P) \to Υ (1S) π^{0}$ with the Belle detector

Belle Collaboration, E. Kovalenko, I. Adachi +164

We report the first evidence for the $h_{b} (2P) \to Υ (1S) η$ transition with a significance of $3.5$ standard deviations. The decay branching fraction is measured to b…

hep-ex2024★ 2 cited

Study of $χ_{b J} (2 P) \to ω Υ (1 S)$ at Belle

Belle Collaboration, Z. S. Stottler, T. K. Pedlar +179

We report a study of the hadronic transitions $χ_{b J} (2 P) \to ω Υ (1 S)$ , with $ω \to π^{+} π^{-} π^{0}$ , using $28.2 \times 1 0^{6} Υ (3 S)$ mesons recorded by the Belle detector. We present the…

Measurement of the energy dependence of the $e^{+} e^{-} \to B B ˉ$ , $B B ˉ^{}$ , and $B^{} B ˉ^{*}$ cross sections at Belle~II

Belle II Collaboration, I. Adachi, L. Aggarwal +466

We report measurements of the $e^{+} e^{-} \to B B ˉ$ , $B B ˉ^{*}$ , and $B^{*} B ˉ^{*}$ cross sections at four energies, 10653, 10701, 10746 and 10805 MeV, using data collected b…

Measurement of $C P$ asymmetries in $B^{0} \to K_{S}^{0} K_{S}^{0} K_{S}^{0}$ decays at Belle II

Belle II Collaboration, I. Adachi, L. Aggarwal +450

We report a measurement of decay-time dependent charge-parity ( $C P$ ) asymmetries in $B^{0} \to K_{S}^{0} K_{S}^{0} K_{S}^{0}$ decays. We use $387 \times 1 0^{6} B B ˉ$ pairs collected at…

Search for the semileptonic decays $Ξ_{c}^{0} \to Ξ^{0} ℓ^{+} ℓ^{-}$ at Belle

Belle Collaboration, J. X. Cui, Y. B. Li +163

Using the full data sample of 980 $fb^{- 1}$ collected with the Belle detector at the KEKB asymmetric energy electron-positron collider, we report the results of the first…

hep-ex2023★ 90 cited

Evidence for $B^{+} \to K^{+} ν ν ˉ$ decays

Belle II Collaboration, I. Adachi, K. Adamczyk +452

We search for the rare decay $B^{+} \to K^{+} ν ν ˉ$ in a $362 fb^{- 1}$ sample of electron-positron collisions at the $Υ (4 S)$ resonance collected with the Belle II det…

hep-ex2023★ 8 cited

Measurement of branching fractions and direct $C P$ asymmetries for $B \to K π$ and $B \to π π$ decays at Belle II

Belle II Collaboration, I. Adachi, L. Aggarwal +435

We report measurements of the branching fractions and direct $CP$ asymmetries of the decays $B^{0} \to K^{+} π^{-}$ , $B^{+} \to K^{+} π^{0}$ , $B^{+} \to K^{0} π^{+}$ , and $B^{0} \to K^{0} π^{0}$ , and…

Measurement of branching-fraction ratios and $C P$ asymmetries in $B^{\pm} \to D_{C P \pm} K^{\pm}$ decays at Belle and Belle II

The Belle, Belle II Collaborations, : +427

We report results from a study of $B^{\pm} \to D K^{\pm}$ decays followed by $D$ decaying to $C P$ ~eigenstates, where $D$ indicates a $D^{0}$ or $D ˉ^{0}$ meson. These decays a…

hep-ex2023★ 7 cited

Tests of light-lepton universality in angular asymmetries of $B^{0} \to D^{*-} ℓ ν$ decays

Belle II Collaboration, I. Adachi, K. Adamczyk +416

We present the first comprehensive tests of light-lepton universality in the angular distributions of semileptonic $B^{0}$ -meson decays to charged spin-1 charmed mesons. We measure f…

hep-ex2023★ 10 cited

Search for a $τ^{+} τ^{-}$ resonance in $e^{+} e^{-} \to μ^{+} μ^{-} τ^{+} τ^{-}$ events with the Belle II experiment

Belle II Collaboration, I. Adachi, K. Adamczyk +464

We report the first search for a non-standard-model resonance decaying into $τ$ pairs in $e^{+} e^{-} \to μ^{+} μ^{-} τ^{+} τ^{-}$ events in the 3.6-10 GeV/ $c^{2}$ mass range. We u…

hep-ex2023★ 5 cited

Measurement of $C P$ asymmetries and branching-fraction ratios for $B^{\pm} \to D K^{\pm}$ and $D π^{\pm}$ with $D \to K_{S}^{0} K^{\pm} π^{\mp}$ using Belle and Belle II data

Belle, Belle II Collaboration, : +408

We measure $C P$ asymmetries and branching-fraction ratios for $B^{\pm} \to D K^{\pm}$ and $D π^{\pm}$ decays with $D \to K_{S}^{0} K^{\pm} π^{\mp}$ , where $D$ is a superposition of $D^{0}$ and…

hep-ex2023★ 16 cited

Search for a long-lived spin-0 mediator in $b \to s$ transitions at the Belle II experiment

Belle II Collaboration, I. Adachi, K. Adamczyk +411

Additional spin-0 particles appear in many extensions of the standard model. We search for long-lived spin-0 particles $S$ in $B$ -meson decays mediated by a $b \to s$ quark transiti…

hep-ex2023★ 5 cited

Precise measurement of the $D_{s}^{+}$ lifetime at Belle II

Belle II Collaboration, I. Adachi, L. Aggarwal +359

We measure the lifetime of the $D_{s}^{+}$ meson using a data sample of 207 fb $^{- 1}$ collected by the Belle II experiment running at the SuperKEKB asymmetric-energy $e^{+} e^{-}$ collider…

Measurement of the $τ$ -lepton mass with the Belle~II experiment

Belle II Collaboration, I. Adachi, K. Adamczyk +418

We present a measurement of the $τ$ -lepton mass using a sample of about 175 million $e^{+} e^{-} \to τ^{+} τ^{-}$ events collected with the Belle II detector at the SuperKEKB $e^{+} e^{-}$ collid…

Search for lepton-flavor-violating $τ^{-} \to ℓ^{-} ϕ$ decays in 2019-2021 Belle II data

Belle II Collaboration, F. Abudinén, I. Adachi +575

We report a search for lepton-flavor-violating decays $τ^{-} \to ℓ^{-} ϕ$ ( $ℓ^{-} = e^{-}, μ^{-}$ ) at the Belle II experiment, using a sample of electron-positron data produced at the Su…

hep-ex2023★ 2 cited

Observation of $B \to D^{(*)} K^{-} K_{S}^{0}$ decays using the 2019-2022 Belle II data sample

Belle II Collaboration, F. Abudinén, I. Adachi +575

We present a measurement of the branching fractions of four $B^{0, -} \to D^{(*) +, 0} K^{-} K_{S}^{0}$ decay modes. The measurement is based on data from SuperKEKB electron-positron colli…