J. Eppelt

activity

20242026

B^{+} \to τ^{+} ν_{τ}

branching fraction with a hadronic tagging method at Belle II

4 citations · 26 across the 35 of their papers we have counts for

collaborators

41 papers

hep-ex2026

Measurements of the branching fractions of $Λ_{c}^{+} \to Λ K^{+} π^{0}$ and $Λ_{c}^{+} \to Λ K^{+} η$ decays at Belle and Belle II

Belle, Belle II Collaborations, : +400

We present a study of the three-body, singly Cabibbo-suppressed decays $Λ_{c}^{+} \to Λ K^{+} π^{0}$ and $Λ_{c}^{+} \to Λ K^{+} η$ using data recorded with the Belle and Belle II detectors at the…

hep-ex2026

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}…

hep-ex2026

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…

hep-ex2026

Search for the $B^{0} \to K_{S}^{0} τ^{+} τ^{-}$ decay

Belle, Belle II Collaborations, : +432

We present the first search for $B^{0} \to K_{S}^{0} τ^{+} τ^{-}$ decays. We look for signal decays in $B^{0} B ˉ^{0}$ events produced in asymmetric-energy electron-positron collisions. T…

hep-ex2026

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…

hep-ex2026

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…

hep-ex2026

Charged-lepton identification at Belle~II

Belle II Collaboration, M. Abumusabh, I. Adachi +409

Effective particle identification capabilities are a strategic priority for the physics program of the Belle~II experiment. We describe the algorithms used at Belle~II for identify…

hep-ex2026

First evidence of $X (3872) \to π^{0} χ_{c 0} (1 P)$ and search for $X (3915) \to π^{0} χ_{c 1} (1 P)$

Belle, Belle II Collaborations, : +412

We search for the pionic transitions $X (3872) \to π^{0} χ_{c J} (1 P)$ $(J = 0, 1, 2)$ and $X (3915) \to π^{0} χ_{c 1}$ in $B^{+} \to π^{0} χ_{c J} K^{+}$ decays using the Belle and Belle~II data samples c…

hep-ex2026

Measurement of mixing-induced CP violation in the decay $B^{0} \to π^{0} π^{0}$

Belle II Collaboration, M. Abumusabh, I. Adachi +437

Measurements of charge-parity (CP) violation in quark transitions provide stringent tests of the current theory and sensitive probes of particles or interactions beyond it. We repo…

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-ex2026

Measurement of time-dependent $C P$ violation parameters in $B^{0} \to K_{S}^{0} π^{0} γ$ decays at Belle and Belle II

Belle, Belle II Collaborations, : +417

We perform a measurement of time-dependent $C P$ violation parameters in $B^{0} \to K_{S}^{0} π^{0} γ$ decays using a dataset of approximately $772 \times 1 0^{6}$ and $521 \times 10^6…

hep-ex2026

Search for $Ξ^{0} p$ , $Ω^{-} p$ , and $Ω^{-} n$ dibaryons in $Υ (1 S)$ and $Υ (2 S)$ decays at Belle

Belle, Belle II Collaborations, : +367

We search for $Ξ^{0} p$ , $Ω^{-} p$ , and $Ω^{-} n$ dibaryon states in $Υ (1 S)$ and $Υ (2 S)$ decays, probing mass regions near the corresponding baryon-pair thresholds. Multistrange baryon-bary…

hep-ex2026

Using Graph Neural Networks for hadronic clustering and to reduce beam background in the Belle~II electromagnetic calorimeter

Jonas Eppelt, Torben Ferber

The Belle~II electromagnetic calorimeter consists of 8376 CsI(Tl) scintillation crystals and is not only used for measuring electromagnetic particles but also for identifying and d…

hep-ex2026

Search for the decay $B^{+} \to K^{+} τ^{+} τ^{-}$ using data from the Belle and Belle II experiments

Belle, Belle II Collaborations, : +435

We report a search for the rare decay $B^{+} \to K^{+} τ^{+} τ^{-}$ using $1.2 \times 1 0^{9}$ $Υ (4 S)$ mesons produced near threshold in electron-positron collisions and colle…

physics.ins-det2026

Real-time graph neural networks on FPGAs for the Belle II electromagnetic calorimeter

I. Haide, M. Neu, Y. Unno +19

We present the development and evaluation of a real-time Graph Neural Network-based trigger module for the electromagnetic calorimeter of the Belle~II experiment at the SuperKEKB c…

hep-ex2026

Study of $B^{+} \to μ^{+} ν_{μ}$ decays at Belle and Belle II

Belle, Belle II Collaborations, : +412

We report a measurement of the branching fraction for the leptonic decay $B^{+} \to μ^{+} ν_{μ}$ . This work presents the first $B^{+} \to μ^{+} ν_{μ}$ result using Belle~II data, an updated Belle me…

hep-ex2025★ 1 cited

Measurement of inclusive $B \to X_{u} ℓ ν$ partial branching fractions and $∣ V_{u b} ∣$ at Belle II

Belle II Collaboration, M. Abumusabh, I. Adachi +419

A sample of 365 fb $^{- 1}$ of $e^{+} e^{-} \to Υ (4 S) \to B B ˉ$ data collected by the Belle II experiment is used to measure the partial branching fractions of charmless semileptonic…

hep-ex2025

Measurements of the mass difference $m (B^{0}) - m (B^{+})$ and the energy dependence of the cross-section ratio $σ (e^{+} e^{-} \to B^{0} B ˉ^{0}) / σ (e^{+} e^{-} \to B^{+} B^{-})$ at Belle and Belle II

Belle, Belle II Collaborations, : +396

Using data samples collected by the Belle and Belle II experiments at the $Υ (4 S)$ resonance with integrated luminosities of 571 fb $^{- 1}$ and 365 fb $^{- 1}$ , respectively, we measur…

hep-ex2025

Observation of the radiative decay $D_{s} (2317)^{+} \to D_{s}^{*} γ$

Belle II Collaboration, M. Abumusabh, I. Adachi +367

We observe the radiative decay $D_{s 0}^{*} (2317)^{+} \to D_{s}^{*+} γ$ for the first time, with a significance exceeding $10$ standard deviations. The signal is found in the contin…

hep-ex2025

Improved measurement of Born cross sections for $χ_{b J} ω$ and $χ_{b J} (π^{+} π^{-} π^{0})_{non - ω}$ ( $J$ = 0, 1, 2) at Belle and Belle II

Belle, Belle II Collaborations, : +424

We study the processes $χ_{b J} ω$ and $χ_{b J} (π^{+} π^{-} π^{0})_{non - ω}$ ( $J$ = 0, 1, 2) at center-of-mass energies $s$ from 10.73 to 11.02 GeV using a $142.5\,\mathrm{fb}^{…

hep-ex2025★ 2 cited

First measurements of the branching fractions for the decay modes $Ξ_{c}^{0} \to Λ η$ and $Ξ_{c}^{0} \to Λ η^{'}$ and search for the decay $Ξ_{c}^{0} \to Λ π^{0}$ using Belle and Belle II data

Belle, Belle II Collaborations, : +321

Using data samples of 988.4 fb $^{- 1}$ and 427.9 fb $^{- 1}$ collected with the Belle and Belle II detectors, we present a study of the singly Cabibbo-suppressed decays $Ξ_c^{0} \to Λ…

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

Search for $e^{+} e^{-} \to γ χ_{b J}$ ( $J$ = 0, 1, 2) near $s = 10.746$ GeV at Belle II

Belle II Collaboration, M. Abumusabh, I. Adachi +399

We search for the $e^{+} e^{-} \to γ χ_{b J}$ ( $J$ = 0, 1, 2) processes at center-of-mass energies $s$ = 10.653, 10.701, 10.746, and 10.804 GeV. These data were collected with the…

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…

Measurements of the branching fractions of Λc+​→ΛK+π0 and Λc+​→ΛK+η decays at Belle and Belle II

Test of lepton flavor universality with Bˉ→D(∗)τ−νˉτ​ and Bˉ→D(∗)ℓ−νˉℓ​ decays at Belle II

Search for the lepton-flavor-violating decay τ±→μ±γ at Belle II

Search for the B0→KS0​τ+τ− decay

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

First measurement of the masses of the Υ1​(1D) and Υ3​(1D) states and the energy dependence of the cross sections for e+e−→ΥJ​(1D)η and e+e−→ΥJ​(1D)π+π−

Charged-lepton identification at Belle~II

First evidence of X(3872)→π0χc0​(1P) and search for X(3915)→π0χc1​(1P)

Measurement of mixing-induced CP violation in the decay B0→π0π0

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

Measurement of time-dependent CP violation parameters in B0→KS0​π0γ decays at Belle and Belle II

Search for Ξ0p, Ω−p, and Ω−n dibaryons in Υ(1S) and Υ(2S) decays at Belle

Using Graph Neural Networks for hadronic clustering and to reduce beam background in the Belle~II electromagnetic calorimeter

Search for the decay B+→K+τ+τ− using data from the Belle and Belle II experiments

Real-time graph neural networks on FPGAs for the Belle II electromagnetic calorimeter

Study of B+→μ+νμ​ decays at Belle and Belle II

Measurement of inclusive B→Xu​ℓν partial branching fractions and ∣Vub​∣ at Belle II

Measurements of the mass difference m(B0)−m(B+) and the energy dependence of the cross-section ratio σ(e+e−→B0Bˉ0)/σ(e+e−→B+B−) at Belle and Belle II

Observation of the radiative decay Ds​(2317)+→Ds∗​γ

Improved measurement of Born cross sections for χbJ​ω and χbJ​(π+π−π0)non−ω​ (J = 0, 1, 2) at Belle and Belle II

First measurements of the branching fractions for the decay modes Ξc0​→Λη and Ξc0​→Λη′ and search for the decay Ξc0​→Λπ0 using Belle and Belle II data

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

Search for e+e−→γχbJ​ (J = 0, 1, 2) near s​=10.746 GeV at Belle II

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

Measurements of the branching fractions of $Λ_{c}^{+} \to Λ K^{+} π^{0}$ and $Λ_{c}^{+} \to Λ K^{+} η$ decays at Belle and Belle II

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

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

Search for the $B^{0} \to K_{S}^{0} τ^{+} τ^{-}$ decay

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 $e^{+} e^{-} \to Υ_{J} (1 D) π^{+} π^{-}$

First evidence of $X (3872) \to π^{0} χ_{c 0} (1 P)$ and search for $X (3915) \to π^{0} χ_{c 1} (1 P)$

Measurement of mixing-induced CP violation in the decay $B^{0} \to π^{0} π^{0}$

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

Measurement of time-dependent $C P$ violation parameters in $B^{0} \to K_{S}^{0} π^{0} γ$ decays at Belle and Belle II

Search for $Ξ^{0} p$ , $Ω^{-} p$ , and $Ω^{-} n$ dibaryons in $Υ (1 S)$ and $Υ (2 S)$ decays at Belle

Search for the decay $B^{+} \to K^{+} τ^{+} τ^{-}$ using data from the Belle and Belle II experiments

Study of $B^{+} \to μ^{+} ν_{μ}$ decays at Belle and Belle II

Measurement of inclusive $B \to X_{u} ℓ ν$ partial branching fractions and $∣ V_{u b} ∣$ at Belle II

Measurements of the mass difference $m (B^{0}) - m (B^{+})$ and the energy dependence of the cross-section ratio $σ (e^{+} e^{-} \to B^{0} B ˉ^{0}) / σ (e^{+} e^{-} \to B^{+} B^{-})$ at Belle and Belle II

Observation of the radiative decay $D_{s} (2317)^{+} \to D_{s}^{*} γ$

Improved measurement of Born cross sections for $χ_{b J} ω$ and $χ_{b J} (π^{+} π^{-} π^{0})_{non - ω}$ ( $J$ = 0, 1, 2) at Belle and Belle II

First measurements of the branching fractions for the decay modes $Ξ_{c}^{0} \to Λ η$ and $Ξ_{c}^{0} \to Λ η^{'}$ and search for the decay $Ξ_{c}^{0} \to Λ π^{0}$ using Belle and Belle II data

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 $e^{+} e^{-} \to γ χ_{b J}$ ( $J$ = 0, 1, 2) near $s = 10.746$ GeV at Belle II

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