P. Ecker

activity

20212026

most citedNew graph-neural-network flavor tagger for Belle II and measurement of

sin 2 ϕ_{1}

B^{0} \to J / ψ K_{S}^{0}

decays

13 citations · 72 across the 19 of their papers we have counts for

collaborators

20 papers

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 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

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-ex2026

A search for feebly-interacting particles in $B$ decays with missing energy at Belle

Belle, Belle II Collaborations, : +406

We present a search for an invisible hidden-sector particle $X_{inv}$ , produced in $B^{0} \to D ˉ^{0} X_{inv}$ and $B^{\pm} \to h X_{inv}$ decays, where $h = π^{\pm}$ , $…

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-ex2024★ 4 cited

Production cross sections of light and charmed mesons in $e^{+} e^{-}$ annihilation near 10.58 GeV

Belle Collaboration, R. Seidl, I. Adachi +131

We report measurements of production cross sections for $ρ^{+}$ , $ρ^{0}$ , $ω$ , $K^{*+}$ , $K^{* 0}$ , $ϕ$ , $η$ , $K_{S}^{0}$ , $f_{0} (980)$ , $D^{+}$ , $D^{0}$ , $D_{s}^{+}$ , $D^{*+}$ , $D^{* 0}$ , and $D^{*+}…

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

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

Search for the baryon number and lepton number violating decays $τ^{-} \to Λ π^{-}$ and $τ^{-} \to Λ ˉ π^{-}$ at Belle II

Belle II Collaboration, I. Adachi, L. Aggarwal +371

We present a search for the baryon number $B$ and lepton number $L$ violating decays $τ^{-} \to Λ π^{-}$ and $τ^{-} \to Λ ˉ π^{-}$ produced from the $e^{+} e^{-} \to τ^{+} τ^{-}$ pro…

hep-ex2024

Determination of the CKM angle $ϕ_{3}$ from a combination of Belle and Belle II results

Belle, Belle II Collaborations, : +399

We report a determination of the CKM angle $ϕ_{3}$ , also known as $γ$ , from a combination of measurements using samples of up to 711~fb $^{- 1}$ from the Belle experiment and up to 3…

hep-ex2024★ 7 cited

Search for Rare $b \to d ℓ^{+} ℓ^{-}$ Transitions at Belle

Belle, Belle II Collaborations, : +393

We present the results of a search for the $b \to d ℓ^{+} ℓ^{-}$ flavor-changing neutral-current rare decays $B^{+, 0} \to (η, ω, π^{+, 0}, ρ^{+, 0}) e^{+} e^{-}$ and $B^{+, 0} \to (η, ω…

hep-ex2024★ 10 cited

Search for a $μ^{+} μ^{-}$ resonance in four-muon final states at Belle II

Belle II Collaboration, I. Adachi, K. Adamczyk +401

We report on a search for a resonance $X$ decaying to a pair of muons in $e^{+} e^{-} \to μ^{+} μ^{-} X$ events in the 0.212-9.000 GeV/ $c^{2}$ mass range, using 178 fb $^{- 1}$ of…

hep-ex2024★ 13 cited

New graph-neural-network flavor tagger for Belle II and measurement of $sin 2 ϕ_{1}$ in $B^{0} \to J / ψ K_{S}^{0}$ decays

Belle II Collaboration, I. Adachi, L. Aggarwal +413

We present GFlaT, a new algorithm that uses a graph-neural-network to determine the flavor of neutral $B$ mesons produced in $Υ (4 S)$ decays. It improves previous algorithms by usin…

hep-ex2024★ 4 cited

Search for a heavy neutral lepton that mixes predominantly with the tau neutrino

Belle Collaboration, M. Nayak, S. Dey +165

We report a search for a heavy neutral lepton (HNL) that mixes predominantly with $ν_{τ}$ . The search utilizes data collected with the Belle detector at the KEKB asymmetric energy $e…

hep-ex2023

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★ 6 cited

Measurement of the branching fraction and $CP$ asymmetry of $B^{0} \to π^{0} π^{0}$ decays using $198 \times 1 0^{6}$ $B B$ pairs in Belle II data

Belle II Collaboration, F. Abudinén, I. Adachi +425

We report measurements of the branching fraction and $CP$ asymmetry in $B^{0} \to π^{0} π^{0}$ decays reconstructed at Belle II in an electron-positron collision sample contain…

hep-ex2023★ 10 cited

Measurement of the $B^{0}$ lifetime and flavor-oscillation frequency using hadronic decays reconstructed in 2019-2021 Belle II data

Belle II Collaboration, F. Abudinén, I. Adachi +393

We measure the $B^{0}$ lifetime and flavor-oscillation frequency using $B^{0} \to D^{(*) -} π^{+}$ decays collected by the Belle II experiment in asymmetric-energy $e^{+} e^{-}$ collisions produ…

hep-ex2023★ 10 cited

Measurement of decay-time-dependent $CP$ violation in $B^{0} \to J / ψ K_{S}^{0}$ decays using 2019-2021 Belle II data

Belle II Collaboration, I. Adachi, L. Aggarwal +392

We report a measurement of the mixing-induced and direct $CP$ violation parameters $S_{CP}$ and $A_{CP}$ from $B^{0} \to J / ψ K_{S}^{0}$ decays reconstructed by the…

hep-ex2022★ 6 cited

Search for a dark leptophilic scalar produced in association with $τ^{+} τ^{-}$ pair in $e^{+} e^{-}$ annihilation at center-of-mass energies near 10.58 GeV

Belle Collaboration, D. Biswas, Sw. Banerjee +177

A dark leptophilic scalar $(ϕ_{L})$ is a hypothetical particle that couples only to leptons rather than quarks. We report on a search for $ϕ_{L}$ in the $e^+e^- \to τ^+ τ^- ϕ_L, ~ϕ_L \…

hep-ex2021★ 1 cited

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

Belle Collaboration, A. Abdesselam, I. Adachi +470

We report results from a study of hadronic transitions of the $χ_{b J} (n P)$ states of bottomonium at Belle. The $P$ -wave states are reconstructed in transitions to the $Υ (1 S)$ with…

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

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

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

A search for feebly-interacting particles in B decays with missing energy at Belle

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

Production cross sections of light and charmed mesons in e+e− annihilation near 10.58 GeV

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

Search for hb​(2P)→γχbJ​(1P) at s​=10.860 GeV

Search for the baryon number and lepton number violating decays τ−→Λπ− and τ−→Λˉπ− at Belle II

Determination of the CKM angle ϕ3​ from a combination of Belle and Belle II results

Search for Rare b→dℓ+ℓ− Transitions at Belle

Search for a μ+μ− resonance in four-muon final states at Belle II

New graph-neural-network flavor tagger for Belle II and measurement of sin2ϕ1​ in B0→J/ψKS0​ decays

Search for a heavy neutral lepton that mixes predominantly with the tau neutrino

Search for the semileptonic decays Ξc0​→Ξ0ℓ+ℓ− at Belle

Measurement of the branching fraction and CP asymmetry of B0→π0π0 decays using 198×106 BB pairs in Belle II data

Measurement of the B0 lifetime and flavor-oscillation frequency using hadronic decays reconstructed in 2019-2021 Belle II data

Measurement of decay-time-dependent CP violation in B0→J/ψKS0​ decays using 2019-2021 Belle II data

Search for a dark leptophilic scalar produced in association with τ+τ− pair in e+e− annihilation at center-of-mass energies near 10.58 GeV

Study of χbJ​(nP)→ωΥ(1S) at Belle

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

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

A search for feebly-interacting particles in $B$ decays with missing energy at Belle

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

Production cross sections of light and charmed mesons in $e^{+} e^{-}$ annihilation near 10.58 GeV

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

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

Search for the baryon number and lepton number violating decays $τ^{-} \to Λ π^{-}$ and $τ^{-} \to Λ ˉ π^{-}$ at Belle II

Determination of the CKM angle $ϕ_{3}$ from a combination of Belle and Belle II results

Search for Rare $b \to d ℓ^{+} ℓ^{-}$ Transitions at Belle

Search for a $μ^{+} μ^{-}$ resonance in four-muon final states at Belle II

New graph-neural-network flavor tagger for Belle II and measurement of $sin 2 ϕ_{1}$ in $B^{0} \to J / ψ K_{S}^{0}$ decays

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

Measurement of the branching fraction and $CP$ asymmetry of $B^{0} \to π^{0} π^{0}$ decays using $198 \times 1 0^{6}$ $B B$ pairs in Belle II data

Measurement of the $B^{0}$ lifetime and flavor-oscillation frequency using hadronic decays reconstructed in 2019-2021 Belle II data

Measurement of decay-time-dependent $CP$ violation in $B^{0} \to J / ψ K_{S}^{0}$ decays using 2019-2021 Belle II data

Search for a dark leptophilic scalar produced in association with $τ^{+} τ^{-}$ pair in $e^{+} e^{-}$ annihilation at center-of-mass energies near 10.58 GeV

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