Y.-K. Kim

activity

20202026

most citedSearch for Axion-Like Particles produced in

e^{+} e^{-}

collisions at Belle II

99 citations · 1k across the 135 of their papers we have counts for

collaborators

157 papers

hep-ex2026

Observation of the decays $B^{+} \to Σ_{c} (2455)^{++} Ξ ˉ_{c}^{' -}$ and $B^{0} \to Σ_{c} (2455)^{0} Ξ ˉ_{c}^{'0}$

Belle, Belle II Collaborations, : +403

We report the first observation of the decays $B^{+} \to Σ_{c} (2455)^{++} Ξ ˉ_{c}^{' -}$ and $B^{0} \to Σ_{c} (2455)^{0} Ξ ˉ_{c}^{'0}$ , with significances of $6.4 σ$ a…

hep-ex2025

First search for $B \to X_{s} ν ν ˉ$ decays

Belle II Collaboration, M. Abumusabh, I. Adachi +440

We report the first search for the flavor-changing neutral-current decays $B \to X_{s} ν ν ˉ$ , where $X_{s}$ is a hadronic system with strangeness equal to 1, in data coll…

hep-ex2025

Observation of $e^{+} e^{-} \to η Υ (2 S)$ and search for $e^{+} e^{-} \to η Υ (1 S), γ X_{b}$ at $s$ near 10.75 GeV

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

We present an analysis of the processes $e^{+} e^{-} \to η Υ (1 S)$ , $η Υ (2 S)$ , and $γ X_{b}$ with $X_{b} \to π^{+} π^{-} χ_{b J}, χ_{b J} \to γ Υ (1 S)$ $(J = 1, 2)$ reconstructed from $γγπ^+π^-\ell^+\ell^-~(…

hep-ex2025★ 1 cited

Search for the lepton-flavor-violating $τ^{-} \to e^{\mp} ℓ^{\pm} ℓ^{\mp}$ decays at Belle II

Belle II Collaboration, I. Adachi, L. Aggarwal +447

We present the result of a search for the charged-lepton-flavor violating decays $τ^{-} \to e^{\mp} ℓ^{\pm} ℓ^{-}$ , where $ℓ$ is a muon or an electron, using a data sample…

hep-ex2025★ 3 cited

Observation of the decays $B^{+} \to Σ_{c} (2455)^{++} Ξ_{c}^{-}$ and $B^{0} \to Σ_{c} (2455)^{0} Ξ_{c}^{0}$

Belle, Belle II Collaborations, : +386

We report the first observation of the two-body baryonic decays $B^{+} \to Σ_{c} (2455)^{++} Ξ_{c}^{-}$ and $B^{0} \to Σ_{c} (2455)^{0} Ξ_{c}^{0}$ with significance…

hep-ex2025★ 1 cited

Measurement of the $D^{0} \to K^{-} π^{+} e^{+} e^{-}$ branching fraction and search for $D^{0} \to π^{+} π^{-} e^{+} e^{-}$ and $D^{0} \to K^{+} K^{-} e^{+} e^{-}$ decays at Belle

Belle, Belle II Collaborations, : +481

We present a study of the rare charm meson decays $D^{0} \to K^{+} K^{-} e^{+} e^{-}$ , $π^{+} π^{-} e^{+} e^{-}$ , and $K^{-} π^{+} e^{+} e^{-}$ using a 942 fb $^{- 1}$ data set c…

hep-ex2025★ 1 cited

Search for an Axion-Like Particle in $B \to K^{(*)} a (\to γ γ)$ Decays at Belle

Belle, Belle II Collaborations, : +422

We report a search for an axion-like particle $a$ in $B \to K^{(*)} a (\to γ γ)$ decays using data collected with the Belle detector at the KEKB asymmetric energy elec…

hep-ex2025★ 2 cited

Measurement of the CP asymmetry in $D^{+} \to π^{+} π^{0}$ decays at Belle II

Belle II Collaboration, I. Adachi, L. Aggarwal +402

We measure the CP asymmetry in $D^{+} \to π^{+} π^{0}$ decays reconstructed in $e^{+} e^{-}$ collisions at the Belle II experiment using a data set corresponding to an integrated luminosity…

hep-ex2025★ 4 cited

Search for a Dark Higgs Boson Produced in Association with Inelastic Dark Matter at the Belle II Experiment

Belle II Collaboration, I. Adachi, L. Aggarwal +437

Inelastic dark matter models that have two dark matter particles and a massive dark photon can reproduce the observed relic dark matter density without violating cosmological limit…

hep-ex2025★ 5 cited

Test of lepton flavor universality with measurements of $R (D^{+})$ and $R (D^{*+})$ using semileptonic $B$ tagging at the Belle II experiment

Belle II Collaboration, I. Adachi, K. Adamczyk +450

We report measurements of the ratios of branching fractions ${\cal R}(D^{(*)+}) = \frac{{\cal B}(\overline{B}{}^0 \to D^{(*)+} \,τ^- \, \overlineν_τ)}{{\cal B}(\overline{B}{}^0 \to…

hep-ex2025

Measurement of the Branching Fraction of $Λ_{c}^{+} \to p K_{S}^{0} π^{0}$ at Belle

The Belle, Belle II Collaborations, : +426

We report a precise measurement of the ratio of branching fractions $B (Λ_{c}^{+} \to p K_{S}^{0} π^{0}) / B (Λ_{c}^{+} \to p K^{-} π^{+})$ using 980 fb $^{- 1}$ of $e^{+} e^{-}$ data from th…

hep-ex2025

Search for Pcs(4459) and Pcs(4338) in Upsilon(1S,2S) inclusive decays at Belle

I. Adachi, L. Aggarwal, H. Ahmed +402

Using data samples of 102 million Upsilon(1S) events and 158 million Upsilon(2S) events collected by the Belle detector at the KEKB asymmetric-energy $e^{+} e^{-}$ collider, we search f…

hep-ex2024

Search for lepton flavor-violating decay modes $B^{0} \to K_{S}^{0} τ^{\pm} ℓ^{\mp} (ℓ = μ, e)$ with hadronic $B$ -tagging at Belle and Belle II

Belle, Belle II Collaborations, : +425

We present the first search for the lepton flavor-violating decay modes $B^{0} \to K_{S}^{0} τ^{\pm} ℓ^{\mp} (ℓ = μ, e)$ using the 711 fb $^{- 1}$ and 365 fb $^{- 1}$ data samples re…

hep-ex2024

Measurement of the branching fraction and $CP$ -violating asymmetry of the decay $B^{0} \to π^{0} π^{0}$ using $387$ million bottom-antibottom meson pairs in Belle II data

Belle II Collaboration, I. Adachi, L. Aggarwal +437

We measure the branching fraction and $CP$ -violating flavor-dependent rate asymmetry of $B^{0} \to π^{0} π^{0}$ decays reconstructed using the Belle II detector in an electron-…

hep-ex2024

Measurement of the branching fraction, polarization, and time-dependent $C P$ asymmetry in $B^{0} \to ρ^{+} ρ^{-}$ decays and constraint on the CKM angle $ϕ_{2}$

Belle II Collaboration, I. Adachi, L. Aggarwal +377

We present a measurement of the branching fraction and fraction of longitudinal polarization of $B^{0} \to ρ^{+} ρ^{-}$ decays, which have two $π^{0}$ 's in the final state. We also measure…

hep-ex2024

Measurement of the inclusive branching fractions for $B_{s}^{0}$ decays into $D$ mesons via hadronic tagging

Belle, Belle II Collaborations, : +452

We report measurements of the absolute branching fractions $B (B_{s}^{0} \to D_{s}^{\pm} X)$ , $B (B_{s}^{0} \to D^{0} / D ˉ^{0} X)$ , and $B (B_{s}^{0} \to D^{\pm} X)$ , w…

hep-ex2024★ 1 cited

Measurement of $B \to K^{*} (892) γ$ decays at Belle II

Belle II Collaboration, I. Adachi, L. Aggarwal +451

We present measurements of $B \to K^{*} (892) γ$ decays using $365 fb^{- 1}$ of data collected from 2019 to 2022 by the Belle~II experiment at the SuperKEKB asymmetric-energy…

hep-ex2024★ 3 cited

Measurement of the time-integrated CP asymmetry in $D^{0} \to K_{S}^{0} K_{S}^{0}$ decays using Belle and Belle II data

Belle, Belle II Collaborations, : +360

We measure the time-integrated CP asymmetry in $D^{0} \to K_{S}^{0} K_{S}^{0}$ decays reconstructed in $e^{+} e^{-} \to c c$ events collected by the Belle a…

hep-ex2024★ 1 cited

Model-independent measurement of $D^{0}$ - $D^{0}$ mixing parameters in $D^{0} \to K_{S}^{0} π^{+} π^{-}$ decays at Belle and Belle II

Belle, Belle II Collaborations, : +339

We perform a model-independent measurement of the $D^{0}$ - $D^{0}$ mixing parameters using samples of $e^{+} e^{-}$ -collision data collected by the Belle and Belle II experiment…

hep-ex2024★ 2 cited

Observation of time-dependent $C P$ violation and measurement of the branching fraction of $B^{0} \to J / ψ π^{0}$ decays

Belle II Collaboration, I. Adachi, L. Aggarwal +391

We present a measurement of the branching fraction and time-dependent charge-parity ( $C P$ ) decay-rate asymmetries in $B^{0} \to J / ψ π^{0}$ decays. The data sample was collected with the…

hep-ex2024

Search for $C P$ violation in $D_{(s)}^{+} \to K_{S}^{0} K^{-} π^{+} π^{+}$ decays using triple and quadruple products

Belle, Belle II Collaborations, : +366

We perform the first search for $C P$ violation in $D_{(s)}^{+} \to K_{S}^{0} K^{-} π^{+} π^{+}$ decays. We use a combined data set from the Belle and Belle II experiments, which s…

hep-ex2024

Determination of $∣ V_{u b} ∣$ from simultaneous measurements of untagged $B^{0} \to π^{-} ℓ^{+} ν_{ℓ}$ and $B^{+} \to ρ^{0} ℓ^{+} ν_{ℓ}$ decays

Belle II Collaboration, I. Adachi, L. Aggarwal +417

We present a measurement of $∣ V_{u b} ∣$ from a simultaneous study of the charmless semileptonic decays $B^{0} \to π^{-} ℓ^{+} ν_{ℓ}$ and $B^{+} \to ρ^{0} ℓ^{+} ν_{ℓ}$ , where $\ell = e, μ…

hep-ex2024

Measurement of branching fractions, CP asymmetry, and isospin asymmetry for $B \to ργ$ decays using Belle and Belle II data

Belle II Collaboration, I. Adachi, K. Adamczyk +407

We present measurements of $B^{+} \to ρ^{+} γ$ and $B^{0} \to ρ^{0} γ$ decays using a combined data sample of $772 \times 1 0^{6}$ $B B$ pairs collected by the Bel…

hep-ex2024

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…

Observation of the decays B+→Σc​(2455)++Ξˉc′−​ and B0→Σc​(2455)0Ξˉc′0​

First search for B→Xs​ννˉ decays

Observation of e+e−→ηΥ(2S) and search for e+e−→ηΥ(1S), γXb​ at s​ near 10.75 GeV

Search for the lepton-flavor-violating τ−→e∓ℓ±ℓ∓ decays at Belle II

Observation of the decays B+→Σc​(2455)++Ξc−​ and B0→Σc​(2455)0Ξc0​

Measurement of the D0→K−π+e+e− branching fraction and search for D0→π+π−e+e− and D0→K+K−e+e− decays at Belle

Search for an Axion-Like Particle in B→K(∗)a(→γγ) Decays at Belle

Measurement of the CP asymmetry in D+→π+π0 decays at Belle II

Search for a Dark Higgs Boson Produced in Association with Inelastic Dark Matter at the Belle II Experiment

Test of lepton flavor universality with measurements of R(D+) and R(D∗+) using semileptonic B tagging at the Belle II experiment

Measurement of the Branching Fraction of Λc+​→pKS0​π0 at Belle

Search for Pcs(4459) and Pcs(4338) in Upsilon(1S,2S) inclusive decays at Belle

Search for lepton flavor-violating decay modes B0→KS0​τ±ℓ∓ (ℓ=μ,e) with hadronic B-tagging at Belle and Belle II

Measurement of the branching fraction and CP-violating asymmetry of the decay B0→π0π0 using 387 million bottom-antibottom meson pairs in Belle II data

Measurement of the branching fraction, polarization, and time-dependent CP asymmetry in B0→ρ+ρ− decays and constraint on the CKM angle ϕ2​

Measurement of the inclusive branching fractions for Bs0​ decays into D mesons via hadronic tagging

Measurement of B→K∗(892)γ decays at Belle II

Measurement of the time-integrated CP asymmetry in D0→KS0​KS0​ decays using Belle and Belle II data

Model-independent measurement of D0-D0 mixing parameters in D0→KS0​π+π− decays at Belle and Belle II

Observation of time-dependent CP violation and measurement of the branching fraction of B0→J/ψπ0 decays

Search for CP violation in D(s)+​→KS0​K−π+π+ decays using triple and quadruple products

Determination of ∣Vub​∣ from simultaneous measurements of untagged B0→π−ℓ+νℓ​ and B+→ρ0ℓ+νℓ​ decays

Measurement of branching fractions, CP asymmetry, and isospin asymmetry for B→ργ decays using Belle and Belle II data

Evidence of hb​(2P)→Υ(1S)η decay and search for hb​(1P,2P)→Υ(1S)π0 with the Belle detector

Observation of the decays $B^{+} \to Σ_{c} (2455)^{++} Ξ ˉ_{c}^{' -}$ and $B^{0} \to Σ_{c} (2455)^{0} Ξ ˉ_{c}^{'0}$

First search for $B \to X_{s} ν ν ˉ$ decays

Observation of $e^{+} e^{-} \to η Υ (2 S)$ and search for $e^{+} e^{-} \to η Υ (1 S), γ X_{b}$ at $s$ near 10.75 GeV

Search for the lepton-flavor-violating $τ^{-} \to e^{\mp} ℓ^{\pm} ℓ^{\mp}$ decays at Belle II

Observation of the decays $B^{+} \to Σ_{c} (2455)^{++} Ξ_{c}^{-}$ and $B^{0} \to Σ_{c} (2455)^{0} Ξ_{c}^{0}$

Measurement of the $D^{0} \to K^{-} π^{+} e^{+} e^{-}$ branching fraction and search for $D^{0} \to π^{+} π^{-} e^{+} e^{-}$ and $D^{0} \to K^{+} K^{-} e^{+} e^{-}$ decays at Belle

Search for an Axion-Like Particle in $B \to K^{(*)} a (\to γ γ)$ Decays at Belle

Measurement of the CP asymmetry in $D^{+} \to π^{+} π^{0}$ decays at Belle II

Test of lepton flavor universality with measurements of $R (D^{+})$ and $R (D^{*+})$ using semileptonic $B$ tagging at the Belle II experiment

Measurement of the Branching Fraction of $Λ_{c}^{+} \to p K_{S}^{0} π^{0}$ at Belle

Search for lepton flavor-violating decay modes $B^{0} \to K_{S}^{0} τ^{\pm} ℓ^{\mp} (ℓ = μ, e)$ with hadronic $B$ -tagging at Belle and Belle II

Measurement of the branching fraction and $CP$ -violating asymmetry of the decay $B^{0} \to π^{0} π^{0}$ using $387$ million bottom-antibottom meson pairs in Belle II data

Measurement of the branching fraction, polarization, and time-dependent $C P$ asymmetry in $B^{0} \to ρ^{+} ρ^{-}$ decays and constraint on the CKM angle $ϕ_{2}$

Measurement of the inclusive branching fractions for $B_{s}^{0}$ decays into $D$ mesons via hadronic tagging

Measurement of $B \to K^{*} (892) γ$ decays at Belle II

Measurement of the time-integrated CP asymmetry in $D^{0} \to K_{S}^{0} K_{S}^{0}$ decays using Belle and Belle II data

Model-independent measurement of $D^{0}$ - $D^{0}$ mixing parameters in $D^{0} \to K_{S}^{0} π^{+} π^{-}$ decays at Belle and Belle II

Observation of time-dependent $C P$ violation and measurement of the branching fraction of $B^{0} \to J / ψ π^{0}$ decays

Search for $C P$ violation in $D_{(s)}^{+} \to K_{S}^{0} K^{-} π^{+} π^{+}$ decays using triple and quadruple products

Determination of $∣ V_{u b} ∣$ from simultaneous measurements of untagged $B^{0} \to π^{-} ℓ^{+} ν_{ℓ}$ and $B^{+} \to ρ^{0} ℓ^{+} ν_{ℓ}$ decays

Measurement of branching fractions, CP asymmetry, and isospin asymmetry for $B \to ργ$ decays using Belle and Belle II data

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