M. Nakao

activity

20242026

collaborators

34 papers

hep-ex2026

First measurement of the masses of the $I^¥_{1} (1 D)$ and $I^¥_{3} (1 D)$ states and the energy dependence of the cross sections for $e^{+} e^{-} \to I^¥_{J} (1 D) I^\cdot$ and $e^{+} e^{-} \to I^¥_{J} (1 D) I ¨ ^{+} I ¨ ^{-}$

Belle, Belle II Collaborations, : +398

We study the processes $e^{+} e^{-} \to I^¥_{J} (1 D) I^\cdot$ and $e^{+} e^{-} \to I^¥_{J} (1 D) I ¨ ^{+} I ¨ ^{-}$ at center-of-mass energies $s$ =(10.73 -- 11.02) GeV using a $142.5 fb^{- 1}$ data sampl…

hep-ex2026

First search for $B \to X_{s} I^½ I^ˉ ½$ decays

Belle II Collaboration, M. Abumusabh, I. Adachi +440

We report the first search for the flavor-changing neutral-current decays $B \to X_{s} I^½ I^ˉ ½$ , where $X_{s}$ is a hadronic system with strangeness equal to 1, in data co…

hep-ex2026

Observation of the decays $B^{+} \to I^£_{c} (2455)^{++} I^ˉ _{c}^{' -}$ and $B^{0} \to I^£_{c} (2455)^{0} I^ˉ _{c}^{'0}$

Belle, Belle II Collaborations, : +403

We report the first observation of the decays $B^{+} \to I^£_{c} (2455)^{++} I^ˉ _{c}^{' -}$ and $B^{0} \to I^£_{c} (2455)^{0} I^ˉ _{c}^{'0}$ , with significances of $6.4\,…

hep-ex2026

Search for the lepton-flavor-violating $I ¨ ^{-} \to e^{\mp} ℓ^{\pm} ℓ^{\mp}$ 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 $I ¨ ^{-} \to e^{\mp} ℓ^{\pm} ℓ^{-}$ , where $ℓ$ is a muon or an electron, using a data sampl…

hep-ex2026

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^{(*)+} \,Ï^- \, \overlineÎ½_Ï)}{{\cal B}(\overline{B}{}^0…

hep-ex2025

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…

First measurement of the masses of the I^¥1​(1D) and I^¥3​(1D) states and the energy dependence of the cross sections for e+e−→I^¥J​(1D)I^⋅ and e+e−→I^¥J​(1D)I¨+I¨−

First search for B→Xs​I^½I^ˉ½ decays

Observation of the decays B+→I^£c​(2455)++I^ˉc′−​ and B0→I^£c​(2455)0I^ˉc′0​

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

Test of lepton flavor universality with measurements of R(D+) and R(D∗+) using semileptonic B tagging at the Belle II experiment

Search for a Dark Higgs Boson Produced in Association with Inelastic Dark Matter at the Belle II Experiment

First measurement of the masses of the $I^¥_{1} (1 D)$ and $I^¥_{3} (1 D)$ states and the energy dependence of the cross sections for $e^{+} e^{-} \to I^¥_{J} (1 D) I^\cdot$ and $e^{+} e^{-} \to I^¥_{J} (1 D) I ¨ ^{+} I ¨ ^{-}$

First search for $B \to X_{s} I^½ I^ˉ ½$ decays

Observation of the decays $B^{+} \to I^£_{c} (2455)^{++} I^ˉ _{c}^{' -}$ and $B^{0} \to I^£_{c} (2455)^{0} I^ˉ _{c}^{'0}$

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

Test of lepton flavor universality with measurements of $R (D^{+})$ and $R (D^{*+})$ using semileptonic $B$ tagging at the Belle II experiment