A5084738188- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Particle Accelerators and Free-Electron Lasers
- Computational Physics and Python Applications
- Medical Imaging Techniques and Applications
- Superconducting Materials and Applications
- Neutrino Physics Research
- Black Holes and Theoretical Physics
- Advanced Mathematical Theories
- Nuclear physics research studies
- Quantum and Classical Electrodynamics
- Machine Learning in Bioinformatics
- Field-Flow Fractionation Techniques
- Numerical Methods and Algorithms
- Cold Atom Physics and Bose-Einstein Condensates
- Hemoglobin structure and function
- Particle Detector Development and Performance
- Biological Research and Disease Studies
University of Göttingen
2017-2022
The experimental results on the ratios of branching fractions R(D)=B(B[over ¯]→Dτ^{-}ν[over ¯]_{τ})/B(B[over ¯]→Dℓ^{-}ν[over ¯]_{ℓ}) and R(D^{*})=B(B[over ¯]→D^{*}τ^{-}ν[over ¯]→D^{*}ℓ^{-}ν[over ¯]_{ℓ}), where ℓ denotes an electron or a muon, show long-standing discrepancy with standard model predictions, might hint at violation lepton flavor universality. We report new simultaneous measurement R(D) R(D^{*}), based data sample containing 772×10^{6} BB[over ¯] events recorded ϒ(4S) resonance...
We present measurements of the branching fractions for decays $B\to K \mu^{+}\mu^{-}$ and e^{+}e^{-}$, their ratio ($R_{K}$), using a data sample 711 $fb^{-1}$ that contains $772 \times 10^{6}$ $B\bar{B}$ events. The were collected at $\Upsilon(4S)$ resonance with Belle detector KEKB asymmetric-energy $e^{+}e^{-}$ collider. $R_{K}$ is measured in five bins dilepton invariant-mass-squared ($q^{2}$): $q^{2} \in (0.1, 4.0), (4.0, 8.12), (1.0, 6.0)$, $(10.2, 12.8)$ ($>14.18) GeV^{2}/c^{4}$,...
We present a new measurement of the Cabibbo-Kobayashi-Maskawa matrix element $|{V}_{cb}|$ from ${B}^{0}\ensuremath{\rightarrow}{D}^{*\ensuremath{-}}{\ensuremath{\ell}}^{+}{\ensuremath{\nu}}_{\ensuremath{\ell}}$ decays, reconstructed with full Belle data set $711\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ integrated luminosity. Two form factor parametrizations, originally conceived by Caprini-Lellouch-Neubert (CLN) and Boyd, Grinstein Lebed (BGL) groups, are used to extract product...
We report the first observation of spontaneous polarization $\mathrm{\ensuremath{\Lambda}}$ and $\overline{\mathrm{\ensuremath{\Lambda}}}$ hyperons transverse to production plane in ${e}^{+}{e}^{\ensuremath{-}}$ annihilation, which is attributed effect arising from a polarizing fragmentation function. For inclusive $\mathrm{\ensuremath{\Lambda}}/\overline{\mathrm{\ensuremath{\Lambda}}}$ production, we also results with subtracted feed-down contributions ${\mathrm{\ensuremath{\Sigma}}}^{0}$...
We report the first measurement of $D^{\ast -}$ meson polarization in decay $B^0 \to D^{*-} \tau^+\nu_{\tau}$ using full data sample 772$\times 10^6$ $B\bar{B}$ pairs recorded with Belle detector at KEKB electron-positron collider. Our result, $F_L^{D^\ast} = 0.60 \pm 0.08 ({\rm stat}) 0.04 sys})$, where $F_L^{D^\ast}$ denotes $D^{\ast-}$ longitudinal fraction, agrees within about $1.7$ standard deviations model prediction.
Using data recorded with the Belle detector, we observe a new excited hyperon, an Ω^{*-} candidate decaying into Ξ^{0}K^{-} and Ξ^{-}K_{S}^{0} mass of 2012.4±0.7(stat)±0.6(syst) MeV/c^{2} width Γ=6.4_{-2.0}^{+2.5}(stat)±1.6(syst) MeV. The is seen primarily in ϒ(1S),ϒ(2S), ϒ(3S) decays.
We present the first measurements of absolute branching fractions ${\mathrm{\ensuremath{\Xi}}}_{c}^{0}$ decays into ${\mathrm{\ensuremath{\Xi}}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$, $\mathrm{\ensuremath{\Lambda}}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$, and $p{K}^{\ensuremath{-}}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ final states. The are made using a dataset comprising $(772\ifmmode\pm\else\textpm\fi{}11)\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected...
We report the first observation of double strange baryon Ξ(1620)^{0} in its decay to Ξ^{-}π^{+} via Ξ_{c}^{+}→Ξ^{-}π^{+}π^{+} decays based on a 980 fb^{-1} data sample collected with Belle detector at KEKB asymmetric-energy e^{+}e^{-} collider. The mass and width are measured be 1610.4±6.0(stat)_{-4.2}^{+6.1} (syst) MeV/c^{2} 59.9±4.8(stat)_{-7.1}^{+2.8}(syst) MeV, respectively. obtain 4.0σ evidence Ξ(1690)^{0} same sample. These results shed light structure hyperon resonances strangeness S=-2.
A bstract We report a new measurement of the e + − → ϒ( nS ) π ( n = 1 , 2 3) cross sections at energies from 10 . 52 to 11 02 GeV using data collected with Belle detector KEKB asymmetric-energy collider. observe structure in energy dependence sections; if described by Breit-Wigner function its mass and width are found be $$ M=\left(10752.7\pm {5.9}_{-1.1}^{+0.7}\right)\mathrm{MeV}/{c}^2 <mml:math...
We report the result for a search leptonic decay of B+→μ+νμ using full Belle dataset 711 fb−1 integrated luminosity at Υ(4S) resonance. In Standard Model B-meson decays are helicity and Cabibbo-Kobayashi-Maskawa suppressed. To maximize sensitivity an inclusive tagging approach is used to reconstruct second B meson produced in collision. The directional information from this boost observed μ into signal rest frame, which has monochromatic momentum spectrum. Though its smeared by experimental...
We present the first measurements of absolute branching fractions $\Xi_c^+$ decays into $\Xi^- \pi^+ \pi^+$ and $p K^- final states. Our analysis is based on a data set $(772\pm 11)\times 10^{6}$ $B\bar{B}$ pairs collected at $\Upsilon(4S)$ resonance with Belle detector KEKB $e^+e^-$ collider. measure fraction $\bar{B}^{0} \to \bar{\Lambda}_{c}^{-} \Xi_{c}^{+}$ recoiling against $\bar{\Lambda}_c^-$ in $\bar{B}^0$ resulting ${\cal B}(\bar{B}^{0} \Xi_{c}^{+}) = [1.16 \pm 0.42(\rm stat.)...
We report results from a study of the spin and parity ${\mathrm{\ensuremath{\Xi}}}_{c}(2970{)}^{+}$ using $980\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ data sample collected by Belle detector at KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. The decay angle distributions in chain...
Using data samples of $e^+e^-$ collisions collected at the $\Upsilon(1S)$, $\Upsilon(2S)$, and $\Upsilon(3S)$ resonances with Belle detector, we search for three-body decay $\Omega(2012)$ baryon to $K\pi\Xi$. This is predicted dominate models describing as a $K\Xi(1530)$ molecule. No significant signals are observed in studied channels, 90\% credibility level upper limits on ratios branching fractions relative $K \Xi$ modes obtained.
We present the result of search for rare $B$ meson decay ${B}^{+}\ensuremath{\rightarrow}{\ensuremath{\ell}}^{+}{\ensuremath{\nu}}_{\ensuremath{\ell}}\ensuremath{\gamma}$ with $\ensuremath{\ell}=\mathrm{e},\ensuremath{\mu}$. For full data set recorded by Belle experiment $711\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ integrated luminosity near $\mathrm{\ensuremath{\Upsilon}}(4\mathrm{S})$ resonance is used. Signal candidates are reconstructed photon energies ${E}_{\ensuremath{\gamma}}$...
We report evidence for the charged charmed-strange baryon $\Xi_{c}(2930)^+$ with a signal significance of 3.9$\sigma$ systematic errors included. The is found in its decay to $K_{S}^{0} \Lambda_{c}^+$ substructure $\bar{B}^{0} \to K^{0}_{S} \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-}$ decays. measured mass and width are $[2942.3 \pm 4.4 (\rm stat.) 1.5(\rm syst.)]$~MeV/$c^{2}$ $[14.8 8.8(\rm 2.5(\rm syst.)]$~MeV, respectively, product branching fraction $\cal{B}(\bar{B}^{0} \Xi_c(2930)^{+}...
We report measurements of the production cross sections charged pions, kaons, and protons as a function fractional energy, event-shape variable called thrust, transverse momentum with respect to thrust axis. These access momenta created in fragmentation process, which are critical importance understanding any transverse-momentum-dependent distribution functions. The low transverse-momentum part can be well described by Gaussians is generally assumed but fractional-energy dependence...
We report the first evidence for $X(3872)$ production in two-photon interactions by tagging either electron or positron final state, exploring highly virtual photon region. The search is performed ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}}J/\ensuremath{\psi}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$, using $825\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of data collected Belle detector operated at KEKB ${e}^{+}{e}^{\ensuremath{-}}$...
We report measurements of isospin asymmetry ${\mathrm{\ensuremath{\Delta}}}_{0\ensuremath{-}}$ and difference direct $CP$ asymmetries $\mathrm{\ensuremath{\Delta}}{A}_{CP}$ between charged neutral $B\ensuremath{\rightarrow}{X}_{s}\ensuremath{\gamma}$ decays. This analysis is based on the data sample containing $772\ifmmode\times\else\texttimes\fi{}{10}^{6}B\overline{B}$ pairs that was collected with Belle detector at KEKB energy-asymmetric ${e}^{+}{e}^{\ensuremath{-}}$ collider. Using a...
We report branching fraction measurements of four decay modes the $\Lambda_{c}^{+}$ baryon, each which includes an $\eta$ meson and a $\Lambda$ baryon in final state, all are measured relative to $\Lambda_{c}^{+} \rightarrow p K^{-} pi^{+}$ mode. The results based on $980~\mathrm{fb^{-1}}$ data sample collected by Belle detector at KEKB asymmetric-energy $e^{+}e^{-}$ collider. Two decays, $\eta \Sigma^{0} \pi^{+}$ $\Lambda(1670) \pi^{+}$, observed for first time, while other modes,...
We report a measurement of time-dependent $CP$ violation parameters in ${B}^{0}\ensuremath{\rightarrow}{K}_{S}^{0}\ensuremath{\eta}\ensuremath{\gamma}$ decays. The study is based on data sample, containing $772\ifmmode\times\else\texttimes\fi{}{10}^{6}B\overline{B}$ pairs, that was collected at the $\mathrm{\ensuremath{\Upsilon}}(4S)$ resonance with Belle detector KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. obtain...
We report a search for $X(3872)$ and $X(3915)$ in $B^+ \to \chi_{c1} \pi^0 K^+$ decays. set an upper limit of $\mathcal{B}(B^+ X(3872) K^+) \times \mathcal{B}(X(3872) \pi^0)$ $ < 8.1 10^{-6}$ X(3915) \mathcal{B}(X(3915) 3.8 10^{-5}$ at 90\% confidence level. also measure $\mathcal{B}(X(3872) \pi^0)/\mathcal{B}(X(3872) J/\psi \pi^+ \pi^-) 0.97$ The results reported here are obtained from $772 10^{6}$ $B\overline{B}$ events collected the $\Upsilon(4S)$ resonance with Belle detector KEKB...
Using 980 $fb^-1$ of data collected with the Belle detector operating at KEKB asymmetric-energy e^+e^- collider, we report a study electromagnetic decays excited {charmed baryons} $\Xi_c(2790)$ and $\Xi_c(2815)$. A clear signal (8.6 standard deviations) is observed for $\Xi_c(2815)^0 \to \Xi_c^0\gamma$, measure: $B[\Xi_c(2815)^0 \Xi_c^0\gamma]/B[\Xi_c(2815)^0 \Xi_c(2645)^+\pi^- \Xi_c^0\pi^+\pi^-] = 0.41 \pm 0.05 0.03$. We also present evidence (3.8 similar decay $\Xi_c(2790)^0$...
Using data samples of $89.5\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$, $711.0\text{ and $121.4\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected with the Belle detector at KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider center-of-mass energies 10.52, 10.58, 10.867 GeV, respectively, we study exclusive reactions ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{cJ}$ ($J=0$, 1, 2)...
We have searched for the lepton-flavor-violating decay $B^{0}\to K^{\ast 0} \mu^{\pm} e^{\mp}$ using a data sample of 711 $fb^{-1}$ that contains $772 \times 10^{6}$ $B\bar{B}$ pairs. The were collected near $\Upsilon (4S)$ resonance with Belle detector at KEKB asymmetric-energy $e^{+}e^{-}$ collider. No signals observed, and we set 90% confidence level upper limits on branching fractions ${\cal B}(B^{0}\to \mu^{+} e^{-})< 1.2\times 10^{-7}$, \mu^{-} e^{+})< 1.6\times and, both decays...