S. Wallner

activity

20222026

B^{+} \to K^{+} ν ν ˉ

decays

90 citations · 185 across the 28 of their papers we have counts for

collaborators

32 papers

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

First Observation of an Exotic Reggeon

G. D. Alexeev, M. G. Alexeev, C. Alice +180

We present new \compass high-statistics measurements of the peripheral production of $η π^{-}$ and $η^{'} π^{-}$ pairs in the reactions $π^{-} p \to η^{(')} π^{-} p$ . For the first t…

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

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

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…

hep-ex2026

Study of $e^{+} e^{-} \to h^{+} h^{-} J / ψ (h = π, K, p)$ via initial-state radiation at Belle~II

Belle II Collaboration, M. Abumusabh, I. Adachi +417

Using a data sample of 427.9 fb $^{- 1}$ collected by the Belle~II detector at or near the $Υ (4 S)$ and $Υ (10753)$ resonances, the cross sections for $e^{+} e^{-} \to h^{+} h^{-} J / ψ$ $(h = π / K / p)$ …

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

Dihadron Transverse-Spin Asymmetries in Muon-Deuteron Deep-Inelastic Scattering

G. D. Alexeev, M. G. Alexeev, C. Alice +168

In 2022, the COMPASS collaboration performed semi-inclusive measurements of deep-inelastic muon-scattering on a transversely polarised deuteron (6LiD) target. From these data, tran…

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

Spectroscopy of Strange Mesons and First Observation of a Strange Crypto-Exotic State with $J^{P} = 0^{-}$

G. D. Alexeev, M. G. Alexeev, C. Alice +160

We measured the strange-meson spectrum in the scattering reaction $K^{-} + p \to K^{-} π^{-} π^{-} + p$ with the COMPASS spectrometer at CERN. Using the world's largest sample 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

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-ex2023

High-statistics measurement of Collins and Sivers asymmetries for transversely polarised deuterons

G. D. Alexeev, M. G. Alexeev, C. Alice +183

New results are presented on a high-statistics measurement of Collins and Sivers asymmetries of charged hadrons produced in deep inelastic scattering of muons on a transversely pol…

hep-ex2023

Final COMPASS results on the transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan process

G. D. Alexeev, M. G. Alexeev, C. Alice +180

The COMPASS Collaboration performed measurements of the Drell-Yan process in 2015 and 2018 using a 190 GeV/c $π^{-}$ beam impinging on a transversely polarised ammonia target. Comb…

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

Strange-Meson Spectroscopy with COMPASS

S. Wallner

While the spectrum of non-strange light mesons is well known, many predicted strange mesons have not yet been observed, and many potentially observed states require further confirm…

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

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…

Search for the B0→KS0​τ+τ− decay

First Observation of an Exotic Reggeon

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

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

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

Study of e+e−→h+h−J/ψ (h=π, K, p) via initial-state radiation 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

Dihadron Transverse-Spin Asymmetries in Muon-Deuteron Deep-Inelastic Scattering

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

Spectroscopy of Strange Mesons and First Observation of a Strange Crypto-Exotic State with JP=0−

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

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

High-statistics measurement of Collins and Sivers asymmetries for transversely polarised deuterons

Final COMPASS results on the transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan process

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

Strange-Meson Spectroscopy with COMPASS

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

Measurement of branching-fraction ratios and CP asymmetries in B±→DCP±​K± decays at Belle and 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 $B^{0} \to π^{0} π^{0}$

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 $e^{+} e^{-} \to h^{+} h^{-} J / ψ (h = π, K, p)$ via initial-state radiation 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

Spectroscopy of Strange Mesons and First Observation of a Strange Crypto-Exotic State with $J^{P} = 0^{-}$

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

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

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

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

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