F. Metzner

activity

20172025

most citedThe Belle II Physics Book

570 citations · 2.4k across the 115 of their papers we have counts for

collaborators

134 papers

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-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

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

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…

hep-ex2024★ 2 cited

Test of light-lepton universality in $τ$ decays with the Belle II experiment

Belle II Collaboration, I. Adachi, K. Adamczyk +428

We present a measurement of the ratio $R_{μ} = B (τ^{-} \to μ^{-} ν ˉ_{μ} ν_{τ}) / B (τ^{-} \to e^{-} ν ˉ_{e} ν_{τ})$ of branching fractions $B$ of the $τ$ lepton decaying t…

hep-ex2024★ 8 cited

Search for lepton-flavor-violating $τ^{-} \to μ^{-} μ^{+} μ^{-}$ decays at Belle II

Belle II Collaboration, I. Adachi, L. Aggarwal +429

We present the result of a search for the charged-lepton-flavor violating decay $τ^{-} \to μ^{-} μ^{+} μ^{-}$ using a $424 f b^{- 1}$ sample of data recorded by the Belle II experiment at the S…

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

Angular analysis of $B \to K^{*} e^{+} e^{-}$ in the low- $q^{2}$ region with new electron identification at Belle

Belle Collaboration, D. Ferlewicz, P. Urquijo +167

We perform an angular analysis of the $B \to K^{*} e^{+} e^{-}$ decay for the dielectron mass squared, $q^{2}$ , range of $0.0008$ to $1.1200 GeV^{2} / c^{4}$ using the full Belle data se…

hep-ex2024

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…

hep-ex2024

Search for a pentaquark state decaying into $p J / ψ$ in $Υ (1, 2 S)$ inclusive decays at Belle

Belle Collaboration, X. Dong, S. M. Zou +162

Using the data samples of 102 million $Υ (1 S)$ and 158 million $Υ (2 S)$ events collected by the Belle detector, we search for a pentaquark state in the $p J / ψ$ final state from $Υ(1,2…

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

Search for Baryon-Number-Violating Processes in $B^{-}$ Decays to the $Ξ ˉ_{c}^{0} Λ ˉ_{c}^{-}$ Final State

Belle Collaboration, T. Gu, V. Savinov +161

We report the results of the first search for $B^{-}$ decays to the $Ξ ˉ_{c}^{0} Λ ˉ_{c}^{-}$ final state using 711~ $f b^{- 1}$ of data collected at the $Υ (4 S)$ resonance wit…

hep-ex2024

A test of lepton flavor universality with a measurement of $R (D^{*})$ using hadronic $B$ tagging at the Belle II experiment

Belle II Collaboration, I. Adachi, K. Adamczyk +434

The ratio of branching fractions $R (D^{*}) = B (B \to D^{*} τ^{-} ν_{τ})$ /$\mathcal{B} (\overline{B} \rightarrow D^{*} \ell^{-} \overlineν_{\ell}…

hep-ex2024

Study of $Υ (10753)$ decays to $π^{+} π^{-} Υ (n S)$ final states at Belle II

Belle II Collaboration, I. Adachi, L. Aggarwal +393

We present an analysis of the process $e^{+} e^{-} \to π^{+} π^{-} Υ (n S)$ (where $n$ = 1, 2, or 3) reconstructed in $19.6$ $f b^{- 1}$ of Belle II data during a special run of the…

hep-ex2023

Search for the $e^{+} e^{-} \to η_{b} (1 S) ω$ and $e^{+} e^{-} \to χ_{b 0} (1 P) ω$ processes at $s = 10.745 GeV$

Belle II Collaboration, I. Adachi, L. Aggarwal +419

We search for the $e^{+} e^{-} \to η_{b} (1 S) ω$ and $e^{+} e^{-} \to χ_{b 0} (1 P) ω$ processes at a center-of-mass energy of 10.745 GeV, which is close to the peak of the $Υ (10753)$ state. We use data…

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

Search for baryon and lepton number violating decays $D \to p ℓ$

Belle Collaboration, S. Maity, R. Garg +159

We search for the baryon and lepton number violating charm decays, $D \to p ℓ$ , where $D$ is either a $D^{0}$ or a $D^{0}$ and $ℓ$ is a muon or an electron, usi…

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…

hep-ex2023

Search for charged-lepton flavor violation in $Υ (2 S) \to ℓ^{\mp} τ^{\pm}$ ( $ℓ = e, μ$ ) decays at Belle

R. Dhamija, S. Nishida, A. Giri +178

We report a search for the charged-lepton flavor violation in $Υ (2 S) \to ℓ^{\mp} τ^{\pm}$ ( $ℓ = e, μ$ ) decays using a $25~\fbi$ $Υ (2 S)$ sample collected by the Belle detector at the…

hep-ex2023

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…

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

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

Measurement of the energy dependence of the e+e−→BBˉ, BBˉ∗, and B∗Bˉ∗ cross sections at Belle~II

Test of light-lepton universality in τ decays with the Belle II experiment

Search for lepton-flavor-violating τ−→μ−μ+μ− decays at Belle II

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

Angular analysis of B→K∗e+e− in the low-q2 region with new electron identification at Belle

Measurement of CP asymmetries in B0→KS0​KS0​KS0​ decays at Belle II

Search for a pentaquark state decaying into pJ/ψ in Υ(1,2S) inclusive decays 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 Baryon-Number-Violating Processes in B− Decays to the Ξˉc0​Λˉc−​ Final State

A test of lepton flavor universality with a measurement of R(D∗) using hadronic B tagging at the Belle II experiment

Study of Υ(10753) decays to π+π−Υ(nS) final states at Belle II

Search for the e+e−→ηb​(1S)ω and e+e−→χb0​(1P)ω processes at s​=10.745GeV

Evidence for B+→K+ννˉ decays

Search for baryon and lepton number violating decays D→pℓ

Measurement of branching fractions and direct CP asymmetries for B→Kπ and B→ππ decays at Belle II

Search for charged-lepton flavor violation in Υ(2S)→ℓ∓τ± (ℓ=e,μ) decays at Belle

Measurement of branching-fraction ratios and CP asymmetries in B±→DCP±​K± decays at Belle and Belle II

Tests of light-lepton universality in angular asymmetries of B0→D∗−ℓν decays

Search for a τ+τ− resonance in e+e−→μ+μ−τ+τ− events with 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 inclusive branching fractions for $B_{s}^{0}$ decays into $D$ mesons via hadronic tagging

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

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

Test of light-lepton universality in $τ$ decays with the Belle II experiment

Search for lepton-flavor-violating $τ^{-} \to μ^{-} μ^{+} μ^{-}$ decays at Belle II

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

Angular analysis of $B \to K^{*} e^{+} e^{-}$ in the low- $q^{2}$ region with new electron identification at Belle

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

Search for a pentaquark state decaying into $p J / ψ$ in $Υ (1, 2 S)$ inclusive decays 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 Baryon-Number-Violating Processes in $B^{-}$ Decays to the $Ξ ˉ_{c}^{0} Λ ˉ_{c}^{-}$ Final State

A test of lepton flavor universality with a measurement of $R (D^{*})$ using hadronic $B$ tagging at the Belle II experiment

Study of $Υ (10753)$ decays to $π^{+} π^{-} Υ (n S)$ final states at Belle II

Search for the $e^{+} e^{-} \to η_{b} (1 S) ω$ and $e^{+} e^{-} \to χ_{b 0} (1 P) ω$ processes at $s = 10.745 GeV$

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

Search for baryon and lepton number violating decays $D \to p ℓ$

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

Search for charged-lepton flavor violation in $Υ (2 S) \to ℓ^{\mp} τ^{\pm}$ ( $ℓ = e, μ$ ) decays at Belle

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

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

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