J. Kumar

activity

20222026

Λ_{c}^{+}

lifetime

9 citations · 20 across the 10 of their papers we have counts for

collaborators

17 papers

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

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

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…

hep-ex2025★ 1 cited

Measurement of the $D^{0} \to K^{-} π^{+} e^{+} e^{-}$ branching fraction and search for $D^{0} \to π^{+} π^{-} e^{+} e^{-}$ and $D^{0} \to K^{+} K^{-} e^{+} e^{-}$ decays at Belle

Belle, Belle II Collaborations, : +481

We present a study of the rare charm meson decays $D^{0} \to K^{+} K^{-} e^{+} e^{-}$ , $π^{+} π^{-} e^{+} e^{-}$ , and $K^{-} π^{+} e^{+} e^{-}$ using a 942 fb $^{- 1}$ data set c…

hep-ex2025

Charged-hadron identification at Belle II

Belle II Collaboration, I. Adachi, H. Ahmed +408

The Belle II experiment's ability to identify particles critically affects the sensitivity of its measurements. We describe Belle II's algorithms for identifying charged particles…

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…

hep-ex2025★ 3 cited

Search for $B^{0} \to K^{* 0} τ^{+} τ^{-}$ decays at the Belle II experiment

Belle II Collaboration, I. Adachi, K. Adamczyk +446

We present a search for the rare flavor-changing neutral-current decay $B^{0} \to K^{* 0} τ^{+} τ^{-}$ with data collected by the Belle II experiment at the SuperKEKB electron-positro…

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-ph2024

Genuine lepton-flavor-universality-violating observables in the $τ - μ$ sector of $B \to (K, K^{*}) ℓℓ$ decays

Ashutosh Kumar Alok, Neetu Raj Singh Chundawat, Jitendra Kumar +2

It was previously shown that unlike the ratios $R_{K}^{μ e} \equiv R_{K} \equiv Γ (B \to K μ^{+} μ^{-}) /Γ (B \to K e^{+} e^{-})$ and $R_{K^*}^{μe} \equiv R_{K^*} \equiv Γ(B \to K^* μ^+ μ^-)/Γ(B \…

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-ex2023

Measurement of the $τ$ -lepton mass with the Belle~II experiment

Belle II Collaboration, I. Adachi, K. Adamczyk +418

We present a measurement of the $τ$ -lepton mass using a sample of about 175 million $e^{+} e^{-} \to τ^{+} τ^{-}$ events collected with the Belle II detector at the SuperKEKB $e^{+} e^{-}$ collid…

hep-ex2022★ 9 cited

Measurement of the $Λ_{c}^{+}$ lifetime

Belle II Collaboration, F. Abudinén, L. Aggarwal +360

An absolute measurement of the $Λ_{c}^{+}$ lifetime is reported using $Λ_{c}^{+} \to p K^{-} π^{+}$ decays in events reconstructed from data collected by the Belle II experiment at the…

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

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

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

Measurement of the D0→K−π+e+e− branching fraction and search for D0→π+π−e+e− and D0→K+K−e+e− decays at Belle

Charged-hadron identification at Belle II

Search for lepton-flavor-violating τ−→ℓ−Ks0​ decays at Belle and Belle II

Search for B0→K∗0τ+τ− decays at 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 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

Genuine lepton-flavor-universality-violating observables in the τ−μ sector of B→(K,K∗)ℓℓ decays

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

Measurement of the τ-lepton mass with the Belle~II experiment

Measurement of the Λc+​ lifetime

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

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

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

Measurement of the $D^{0} \to K^{-} π^{+} e^{+} e^{-}$ branching fraction and search for $D^{0} \to π^{+} π^{-} e^{+} e^{-}$ and $D^{0} \to K^{+} K^{-} e^{+} e^{-}$ decays at Belle

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

Search for $B^{0} \to K^{* 0} τ^{+} τ^{-}$ decays at 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

Genuine lepton-flavor-universality-violating observables in the $τ - μ$ sector of $B \to (K, K^{*}) ℓℓ$ decays

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

Measurement of the $τ$ -lepton mass with the Belle~II experiment

Measurement of the $Λ_{c}^{+}$ lifetime