S. Cunliffe
A5101511387- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Black Holes and Theoretical Physics
- Particle Accelerators and Free-Electron Lasers
- Computational Physics and Python Applications
- Medical Imaging Techniques and Applications
- Superconducting Materials and Applications
- Atomic and Subatomic Physics Research
- Cosmology and Gravitation Theories
- Scientific Computing and Data Management
- Distributed and Parallel Computing Systems
- Stochastic processes and statistical mechanics
- Radiation Detection and Scintillator Technologies
- Advanced NMR Techniques and Applications
- Nuclear physics research studies
- Particle accelerators and beam dynamics
- Cold Atom Physics and Bose-Einstein Condensates
- Neural Networks and Applications
- Sensor Technology and Measurement Systems
- Physics of Superconductivity and Magnetism
- Pulsars and Gravitational Waves Research
Deutsches Elektronen-Synchrotron DESY
2018-2023
Campbell Collaboration
2021
Imperial College London
2012-2018
Pacific Northwest National Laboratory
2018
Istituto Nazionale di Fisica Nucleare, Sezione di Bari
2014-2018
University of the Basque Country
2018
Laboratoire d’Annecy de Physique des Particules
2018
Institut National de Physique Nucléaire et de Physique des Particules
2018
Centre National de la Recherche Scientifique
2018
Universitat de Barcelona
2018
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 a measurement of ${R}_{{K}^{*}}$, the branching fraction ratio $\mathcal{B}(B\ensuremath{\rightarrow}{K}^{*}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})/\mathcal{B}(B\ensuremath{\rightarrow}{K}^{*}{e}^{+}{e}^{\ensuremath{-}})$, for both charged and neutral $B$ mesons. The case ${R}_{{K}^{*+}}$ is first ever performed. In addition, we report absolute fractions individual modes in bins squared dilepton invariant mass ${q}^{2}$. analysis based on data sample $711\text{...
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 search for the rare decay <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi>B</a:mi><a:mo>+</a:mo></a:msup><a:mo stretchy="false">→</a:mo><a:msup><a:mi>K</a:mi><a:mo>+</a:mo></a:msup><a:mi>ν</a:mi><a:mover accent="true"><a:mi>ν</a:mi><a:mo stretchy="false">¯</a:mo></a:mover></a:math> in a <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" display="inline"><f:mn>362</f:mn><f:mtext> </f:mtext><f:mtext>...
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 a measurement of the ratios branching fractions $\mathcal{R}(D) = {\cal B}(\bar{B} \to D \tau^- \bar{\nu}_{\tau})/{\cal \ell^- \bar{\nu}_{\ell})$ and $\mathcal{R}(D^{\ast}) D^* \bar{\nu}_{\ell})$, where $\ell$ denotes an electron or muon. The results are based on data sample containing $772\times10^6$ $B\bar{B}$ events recorded at $\Upsilon(4S)$ resonance with Belle detector KEKB $e^+ e^-$ collider. analysis utilizes method tag-side $B$ meson is reconstructed in semileptonic decay...
We present a search for the direct production of light pseudoscalar decaying into two photons with Belle II detector at SuperKEKB collider. process e^{+}e^{-}→γa, a→γγ in mass range 0.2<m_{a}<9.7 GeV/c^{2} using data corresponding to an integrated luminosity (445±3) pb^{-1}. Light pseudoscalars interacting predominantly standard model gauge bosons (so-called axionlike particles or ALPs) are frequently postulated extensions model. find no evidence ALPs and set 95% confidence level upper...
The full event interpretation is presented: a new exclusive tagging algorithm used by the high-energy physics experiment Belle II. experimental setup of II allows precise measurement otherwise inaccessible B meson decay modes. Full Event Interpretation enables many these measurements. relies on machine learning to automatically identify plausible chains based data recorded detector. Compared similar algorithms employed previous experiments, provides greater efficiency, yielding larger...
A search for the flavor-changing neutral-current decay B^{+}→K^{+}νν[over ¯] is performed at Belle II experiment SuperKEKB asymmetric energy electron-positron collider. The data sample corresponds to an integrated luminosity of 63 fb^{-1} collected ϒ(4S) resonance and a 9 60 MeV below resonance. Because measurable signature involves only single charged kaon, novel measurement approach used that exploits not properties decay, but also inclusive other B meson in ϒ(4S)→BB[over event, suppress...
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.
Theories beyond the standard model often predict existence of an additional neutral boson, $Z^{\prime}$. Using data collected by Belle II experiment during 2018 at SuperKEKB collider, we perform first searches for invisible decay a $Z^{\prime}$ in process $e^+ e^- \to \mu^+ \mu^- Z^{\prime}$ and lepton-flavor-violating e^{\pm} \mu^{\mp} Z^{\prime}$. We do not find any excess events set 90\% credibility level upper limits on cross sections these processes. translate former, framework...
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...
Charged lepton flavor violation is forbidden in the Standard Model but possible several new physics scenarios. In many of these models, radiative decays $\tau^{\pm}\rightarrow\ell^{\pm}\gamma$ ($\ell=e,\mu$) are predicted to have a sizeable probability, making them particularly interesting channels search at various experiments. An updated via using full data Belle experiment, corresponding an integrated luminosity 988 fb$^{-1}$, reported for charged violation. No significant excess over...
Abstract We report on new flavor tagging algorithms developed to determine the quark-flavor content of bottom ( "Image missing"<!-- image only, no MathML or LaTex -->) mesons at Belle II. The provide essential inputs for measurements mixing and charge-parity violation. validate evaluate performance using hadronic --> decays with flavor-specific final states reconstructed in a data set corresponding an integrated luminosity 62.8 fb $$^{-1}$$ <mml:math...
We study the processes e^{+}e^{-}→ωχ_{bJ}(1P) (J=0, 1, or 2) using samples at center-of-mass energies sqrt[s]=10.701, 10.745, and 10.805 GeV, corresponding to 1.6, 9.8, 4.7 fb^{-1} of integrated luminosity, respectively. These data were collected with Belle II detector during special operations SuperKEKB collider above ϒ(4S) resonance. report first observation ωχ_{bJ}(1P) signals sqrt[s]=10.745 GeV. By combining results sqrt[s]=10.867 we find energy dependencies Born cross sections for...
We present the first measurement of ratio branching fractions inclusive semileptonic B-meson decays, R(X_{e/μ})=B(B→Xeν)/B(B→Xμν), a precision test electron-muon universality, using data corresponding to 189 fb^{-1} from electron-positron collisions collected with Belle II detector. In events where partner B meson is fully reconstructed, we use fits lepton momentum spectra above 1.3 GeV/c obtain R(X_{e/μ})=1.007±0.009(stat)±0.019(syst), which most precise lepton-universality its kind and...
We search for lepton-flavor-violating τ^{-}→e^{-}α and τ^{-}→μ^{-}α decays, where α is an invisible spin-0 boson. The uses electron-positron collisions at 10.58 GeV center-of-mass energy with integrated luminosity of 62.8 fb^{-1}, produced by the SuperKEKB collider collected Belle II detector. excess in lepton-energy spectrum known τ^{-}→e^{-}ν[over ¯]_{e}ν_{τ} τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ} decays. report 95% confidence-level upper limits on branching-fraction ratio...
The $L_{\mu}-L_{\tau}$ extension of the standard model predicts existence a lepton-flavor-universality-violating $Z^{\prime}$ boson that couples only to heavier lepton families. We search for such $Z^\prime$ through its invisible decay in process $e^+ e^- \to \mu^+ \mu^- Z^{\prime}$. use sample electron-positron collisions at center-of-mass energy 10.58GeV collected by Belle II experiment 2019-2020, corresponding an integrated luminosity 79.7fb$^{-1}$. find no excess over expected...
We report the first observation of $$\Xi _{c}(2930)^0$$ charmed-strange baryon with a significance greater than 5 $$\sigma $$ . The is found in its decay to $$K^- \Lambda _{c}^+$$ $$B^{-} \rightarrow K^{-} _{c}^{+} \bar{\Lambda }_{c}^{-}$$ decays. measured mass and width are $$[2928.9 \pm 3.0(\mathrm stat.)^{+0.9}_{-12.0}(\mathrm syst.)]$$ MeV/ $$c^{2}$$ $$[19.5 8.4(\mathrm stat.) ^{+5.9}_{-7.9}(\mathrm MeV, respectively, product branching fraction $$\mathcal{B}(B^{-} \Xi _{c}(2930)^0...
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...