S. Al Said
A5072507962- 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
- Neutrino Physics Research
- Black Holes and Theoretical Physics
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Superconducting Materials and Applications
- Medical Imaging Techniques and Applications
- Nuclear physics research studies
- Cosmology and Gravitation Theories
- Muon and positron interactions and applications
- Astrophysics and Cosmic Phenomena
- Atrial Fibrillation Management and Outcomes
- Distributed and Parallel Computing Systems
- Advanced NMR Techniques and Applications
- Atomic and Subatomic Physics Research
- NMR spectroscopy and applications
- Radioactive Decay and Measurement Techniques
- Biological Research and Disease Studies
- Machine Learning in Bioinformatics
- Coding theory and cryptography
- Reproductive Health and Technologies
Thrombolysis in Myocardial Infarction Study Group
2024
Brigham and Women's Hospital
2024
Harvard University
2024
Universitäts-Herzzentrum Freiburg-Bad Krozingen
2023
University of Cincinnati
2023
King Abdulaziz University
2014-2022
University of Tabuk
2014-2022
Korea Institute of Science & Technology Information
2015-2018
Korea University
2015-2018
Istituto Nazionale di Fisica Nucleare, Sezione di Bari
2018
We report a measurement of the branching fraction ratios R(D(*)) Bbar -> D(*) tau- nubar_tau relative to D()* l- nubar_l (where l = e or mu) using full Belle data sample 772 x 10^6 BBbar pairs collected at Y(4S) resonance with detector KEKB asymmetric-energy e+e- collider. The measured values are R(D)= 0.375 +- 0.064(stat.) 0.026(syst.) and R(D*) 0.293 0.038(stat.) 0.015(syst.). analysis uses hadronic reconstruction tag-side B meson purely leptonic tau decays. results consistent earlier...
We report the first measurement of $\ensuremath{\tau}$ lepton polarization ${P}_{\ensuremath{\tau}}({D}^{*})$ in decay $\overline{B}\ensuremath{\rightarrow}{D}^{*}{\ensuremath{\tau}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\tau}}$ as well a new ratio branching fractions...
We present a measurement of angular observables and test lepton flavor universality in the $B\ensuremath{\rightarrow}{K}^{*}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$ decay, where $\ensuremath{\ell}$ is either $e$ or $\ensuremath{\mu}$. The analysis performed on data sample corresponding to an integrated luminosity $711\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ containing $772\ifmmode\times\else\texttimes\fi{}1{0}^{6}$ $B\overline{B}$ pairs, collected at...
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...
With the full data sample of $772 \times 10^6$ $B{\bar B}$ pairs recorded by Belle detector at KEKB electron-positron collider, decay $\bar{B} \rightarrow D^* \tau^- \bar{\nu}_\tau$ is studied with hadronic $\tau$ decays $\tau^- \pi^- \nu_\tau$ and \rho^- \nu_\tau$. The polarization $P_\tau(D^*)$ in two-body measured, as well ratio branching fractions $R(D^{*}) = \mathcal{B}(\bar {B} \bar{\nu}_\tau) / \mathcal{B}(\bar{B} \ell^- \bar{\nu}_\ell)$, where $\ell^-$ denotes an electron or a muon....
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 the results of an amplitude analysis anti-B0 -> J/psi K- pi+ decays. A new charged charmoniumlike state Zc(4200)+ decaying to is observed with a significance 6.2 sigma. The mass and width are 4196 +31-29 +17-13 MeV/c^2 370 +70-70 +70-132 MeV, respectively; preferred assignment quantum numbers J^P = 1^+. In addition, we find evidence for Zc(4430)+ pi+. based on 711 fb^-1 data sample collected by Belle detector at asymmetric-energy e+ e- collider KEKB.
We present the results of a search for rare decays $B\to h\nu\overline{\nu}$, where $h$ stands $K^+,\:K^0_{\mathrm{S}},\:K^{\ast +},\:K^{\ast 0},\:\pi^+,\:\pi^0,\:\rho^+$ and $\rho^{0}$. The are obtained with $772\times10^{6}$ $B\overline{B}$ pairs collected Belle detector at KEKB $e^+ e^-$ collider. reconstruct one $B$ meson in semileptonic decay require single but nothing else on signal side. observe no significant set upper limits branching fractions. K^0_{\mathrm{S}}\nu\overline{\nu}$,...
We present a determination of the magnitude Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$ using decay $B\to D\ell\nu_\ell$ ($\ell=e,\mu$) based on 711 fb$^{-1}$ $e^+e^-\to \Upsilon(4S)$ data recorded by Belle detector and containing $772 \times 10^6$ $B\bar{B}$ pairs. One $B$ meson in event is fully reconstructed hadronic mode while other, signal side, partially from charged lepton either $D^+$ or $D^0$ total 23 modes. The isospin-averaged branching fraction found to be...
We report measurement of the cross section $e^+e^-\to \pi^+\pi^-\psi(2S)$ between 4.0 and $5.5 {\rm GeV}$, based on an analysis initial state radiation events in a $980 \rm fb^{-1}$ data sample recorded with Belle detector. The properties $Y(4360)$ $Y(4660)$ states are determined. Fitting mass spectrum $\pi^+\pi^-\psi(2S)$ two coherent Breit-Wigner functions, we find solutions identical width but different couplings to electron-positron pairs: $M_{Y(4360)} = (4347\pm 6\pm 3) MeV}/c^2$,...
We present a measurement of angular observables and test lepton flavor universality in the $B\to K^\ast \ell^+\ell^-$ decay, where $\ell$ is either $e$ or $μ$. The analysis performed on data sample corresponding to an integrated luminosity $711~\mathrm{fb}^{-1}$ containing $772\times 10^{6}$ $B\bar B$ pairs, collected at $Υ(4S)$ resonance with Belle detector asymmetric-energy $e^+e^-$ collider KEKB. result consistent Standard Model (SM) expectations, largest discrepancy from SM prediction...
We present a measurement of angular observables, $P_4'$, $P_5'$, $P_6'$, $P_8'$, in the decay $B^0 \to K^\ast(892)^0 \ell^+ \ell^-$, where $\ell^+\ell^-$ is either $e^+e^-$ or $\mu^+\mu^-$. The analysis performed on data sample corresponding to an integrated luminosity $711~\mathrm{fb}^{-1}$ containing $772\times 10^{6}$ $B\bar B$ pairs, collected at $\Upsilon(4S)$ resonance with Belle detector asymmetric-energy collider KEKB. Four $P_{4,5,6,8}'$ are extracted five bins invariant mass...
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...
Using the entire Belle data sample of 980 ${\rm fb}^{-1}$ $e^+e^-$ collisions, we present results a study excited $\Omega_c$ charmed baryons in decay mode $\Xi_c^+K^-$. We show confirmation four five narrow states reported by LHCb Collaboration: $\Omega_c(3000)$ , $\Omega_c(3050)$, $\Omega_c(3066)$, and $\Omega_c(3090)$.
We present a measurement of the differential shapes exclusive $B\ensuremath{\rightarrow}{D}^{*}\ensuremath{\ell}{\overline{\ensuremath{\nu}}}_{\ensuremath{\ell}}$ ($B={B}^{\ensuremath{-}},{\overline{B}}^{0}$ and $\ensuremath{\ell}=e$, $\ensuremath{\mu}$) decays with hadronic tag-side reconstruction for full $711\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ Belle dataset. extract Caprini-Lellouch-Neubert (CLN) Boyd-Grinstein-Lebed (BGL) form factor parameters use an external input absolute...
We report results on studies of the e+e- annihilation into three-body Y(nS)pi+pi- (n=1,2,3) final states including measurements cross sections and full amplitude analysis. The measured at sqrt(s)=10.865 GeV corrected for initial state radiation are sigma(e+e-=>Y(1S)pi+pi-)=(2.27+-0.12+-0.14) pb, sigma(e+e-=>Y(2S)pi+pi-)=(4.07+-0.16+-0.45) sigma(e+e-=>Y(3S)pi+pi-)=(1.46+-0.09+-0.16) pb. Amplitude analysis strongly favors I^G(J^P)=1^+(1^+) quantum-number assignments two bottomonium-like Zb+-...
We perform a full amplitude analysis of the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}D\overline{D}$, where $D$ refers to either ${D}^{0}$ or ${D}^{+}$. A new charmoniumlike state ${X}^{*}(3860)$ that decays $D\overline{D}$ is observed with significance $6.5\ensuremath{\sigma}$. Its mass $({3862}_{\ensuremath{-}32}^{+26}{\text{ }}_{\ensuremath{-}13}^{+40})\text{ }\text{ }\mathrm{MeV}/{c}^{2}$, and its width $({201}_{\ensuremath{-}67}^{+154}{\text{...
Received 25 April 2018DOI:https://doi.org/10.1103/PhysRevD.97.099902© 2018 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasFlavor changing neutral currentsParticle decaysParticle interactionsParticles & Fields
A new measurement of the branching fraction leptonic decay ${B}^{+}\ensuremath{\rightarrow}{\ensuremath{\tau}}^{+}\phantom{\rule{0}{0ex}}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ confirms previous measurements and agrees with standard model predictions.
We use 772$\times 10^6$ $B \bar{B}$ meson pairs collected at the $\Upsilon(4S)$ resonance with Belle detector to measure branching fraction for $\bar{B} \rightarrow X_s \gamma$. Our measurement uses a sum-of-exclusives approach in which 38 of hadronic final states strangeness equal $+1$, denoted by $X_s$, are reconstructed. The inclusive $M_{X_s}<$ 2.8 GeV/$c^2$, corresponds minimum photon energy 1.9 GeV, is measured be ${\cal B}(\bar{B} \gamma)=(3.51\pm0.17\pm0.33)\times10^{-4}$, where...
The dark photon ${A}^{\ensuremath{'}}$ and the Higgs boson ${h}^{\ensuremath{'}}$ are hypothetical constituents featured in a number of recently proposed sector models. Assuming prompt decays both particles, we search for their production so-called Higgstrahlung channel ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{A}^{\ensuremath{'}}{h}^{\ensuremath{'}}$, with ${h}^{\ensuremath{'}}\ensuremath{\rightarrow}{A}^{\ensuremath{'}}{A}^{\ensuremath{'}}$. We investigate ten exclusive final...
We report a measurement of the differential cross section ${\ensuremath{\pi}}^{0}$ pair production in single-tag two-photon collisions, ${\ensuremath{\gamma}}^{*}\ensuremath{\gamma}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}$, ${e}^{+}{e}^{\ensuremath{-}}$ scattering. The is measured for ${Q}^{2}$ up to $30\text{ }\text{ }{\mathrm{GeV}}^{2}$, where negative invariant mass squared tagged photon, kinematic range $0.5\text{ }\mathrm{GeV}<W<2.1\text{ }\mathrm{GeV}$ and...
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.