Q. Liu

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 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…

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…

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…

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…

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…

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…

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…

First measurement of the absolute branching fractions of $Σ^{+}$ nonleptonic decays and test of the $Δ I = 1/2$ rule

BESIII Collaboration, M. Ablikim, M. N. Achasov +689

Based on $(10087 \pm 44) \times 1 0^{6}$ $J / ψ$ events collected by the BESIII detector at the center-of-mass energy $s = 3.097$ GeV, the first absolute measurement of the branc…

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…

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…

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…

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★ 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…

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

Belle, Belle II Collaborations, : +375

We present the results of a search for the charged-lepton-flavor violating decays $B^{0} \to K^{* 0} τ^{\pm} ℓ^{\mp}$ , where $ℓ^{\mp}$ is either an electron or a muon. The…

hep-ex2025★ 1 cited

Search for lepton-flavor-violating $τ^{-} \to ℓ^{-} K_{s}^{0}$ decays at Belle and Belle II

Belle, Belle II Collaborations, : +419

We present the results of a search for charged-lepton-flavor violating decays $τ^{-} \to ℓ^{-} K_{S}^{0}$ , where $ℓ^{-}$ is either an electron or a muon. We combine $e…

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★ 4 cited

Measurement of $B^{+} \to τ^{+} ν_{τ}$ branching fraction with a hadronic tagging method at Belle II

Belle II Collaboration, I. Adachi, K. Adamczyk +341

We present a measurement of the branching fraction of $B^{+} \to τ^{+} ν_{τ}$ decays using $(387 \pm 6) \times 1 0^{6}$ $Υ (4 S)$ collected between 2019 and 2022 with the Belle II detector at the S…

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…

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…

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-…

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…