Now showing items 4880-4899 of 7445

    • Observation of Floquet Bands in Driven Spin-Orbit-Coupled Fermi Gases 

      Huang, L.; Peng, P.; Li, D.; Meng, Z.; Chen, L.; Qu, Chunlei; Wang, P.; Zhang, Chuanwei; Zhang, J.
      Periodic driving of a quantum system can significantly alter its energy bands and even change the band topology, opening a completely new avenue for engineering novel quantum matter. Although important progress has been ...
    • Observation of J/ψ → pp̅α₀(980) at BESII 

      Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; An, F. F.; Lou, Xinchou (2014-09-26)
      Using 2.25 x 10⁸ J/ψ events collected with the BESIII detector at the BEPCII storage rings, we observe for the first time the process J/ψ → pp̅α₀(980), α₀ → π⁰η with a significance of 6.5σ (3.2σ including systematic ...
    • Observation of Spin Correlation in tt̄ Events from pp Collisions at √s = 7 TeV Using the ATLAS Detector 

      Aad, G.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Ahsan, Mahsana; Izen, Joseph M.; Lou, Xinchou; Reeves, Kendall; Wong, Wei-Cheng; ATLAS Collaboration (American Physical Society, 2012-05-24)
      A measurement of spin correlation in tt̅ production is reported using data collected with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 2.1 fb⁻¹. Candidate events are selected in the dilepton ...
    • Observation of the Decay Λ_c⁺→ Σ⁻π⁺π⁺π⁰ 

      Ablikim, M.; Achasov, M. N.; Ahmed, S.; Albrecht, M.; Amoroso, A.; An, F. F.; An, Q.; Lou, Xinchou (Elsevier B.V, 2017)
      We report the first observation of the decay Λ_c⁺→ Σ⁻π⁺π⁺π⁰, based on data obtained in e⁺e⁻ annihilations with an integrated luminosity of 567 pb⁻¹ at √s̅=4.6 GeV. The data were collected with the BESIII detector at the ...
    • Observation of the Helicity-Selection-Rule Suppressed Decay of the χ(c2) Charmonium State 

      Ablikim, M.; Achasov, M. N.; Ahmed, S.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Lou, Xinchou; BESIII Collaboration (Amer Physical Soc, 2018-10-01)
      The decays of χ(c2) → K⁺K⁻ π⁰, K(S)K(±)π(∓), and π⁺π⁻π⁰ are studied with the ψ(3686) data samples collected with the Beijing Spectrometer ( BESIII). For the first time, the branching fractions of χ(c2) → K*K̅, χ(c2) → ...
    • Observation of the Isospin-Violating Decay J/ψ → φπ⁰ f₀(980) 

      Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Amoroso, A.; Lou, Xinchou; BESIII Collaboration (Amer Physical Soc, 2015-07)
      Using a sample of 1.31 x 10⁹ J/ψ events collected with the BESIII detector at the BEPCII collider, the decays J/ψ → φπ⁺π⁻π⁰ and J/ψ → φπ⁰π⁰π⁰ are investigated. The isospin-violating decay J/ψ → φπ⁰f₀(980) with f₀(980) → ...
    • Observation of the Singly Cabibbo-Suppressed Decay D⁺ → ωπ⁺ and Evidence for D⁰ → ωπ⁰ 

      Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Amoroso, A.; Lou, Xinchou; BESIII Collaboration (American Physical Society, 2016-02-23)
      Based on 2.93 fb⁻¹ e⁺e⁻ collision data taken at center-of-mass energy of 3.773 GeV by the BESIII detector, we report searches for the singly Cabibbo-suppressed decays D⁺ → ωπ⁺ and D⁰ → ωπ⁰. A double tag technique is used ...
    • Observation of Time-Reversal Violation in the B⁰ Meson System 

      Lees, J. P.; Poireau, V.; Tisserand, V.; Grauges, E.; Palano, A.; Eigen, G.; Izen, Joseph M.; Lou, Xinchou; BaBar Collaboration (American Physical Society, 2012-11-19)
      Although CP violation in the B meson system has been well established by the B factories, there has been no direct observation of time-reversal violation. The decays of entangled neutral B mesons into definite flavor states ...
    • Observation of Top-Quark Pair Production in Association with a Photon and Measurement of the tt̅γ Production Cross Section in pp Collisions at √s=7 TeV Using the ATLAS Detector 

      Aad, G.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Izen, Joseph M.; Leyton, Michael; Lou, Xinchou; Namasivayam, Harisankar; Reeves, Kendall; ATLAS Collaboration (Amer Physical Soc, 2015-04-01)
      A search is performed for top-quark pairs tt̅ produced together with a photon (γ) with transverse energy greater than 20 GeV using a sample of tt̅ candidate events in final states with jets, missing transverse momentum, ...
    • Observation of Z_c (3900)⁰ in e⁺e⁻ → π⁰π⁰J/ψ 

      Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Amoroso, A.; Lou, Xinchou; BESIII Collaboration (2015-09-11)
      Using a data sample collected with the BESIII detector operating at the BEPCII storage ring, we observe a new neutral state Z_c (3900)⁰ with a significance of 10.4σ. The mass and width are measured to be 3894.8 ± 2.3 ± 3.2 ...
    • Observation of η'→π⁺π⁻π⁺π⁻ and η'→π⁺π⁻π⁰π⁰ 

      Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; An, F. F.; Lou, Xinchou (2014-06-25)
      Using a sample of 1.3 x 10⁹ J/ψ events collected with the BESIII detector, we report the first observation of η'→π⁺π⁻π⁺π⁻ and η'→π⁺π⁻π⁰π⁰. The measured branching fractions are ℬ(η'→π⁺π⁻π⁺π⁻) = [8.53 ± 0.69(stat.) ± ...
    • Observation of η′ → ωe⁺e⁻ 

      Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Amoroso, A.; Lou, Xinchou; BESIII Collaboration (Amer Physical Soc, 2015-09-15)
      Based on a sample of η′ mesons produced in the radiative decay J/ψ → γη′ in 1.31 x 10⁹ J/ψ events collected with the BESIII detector, the decay η′ → ωe⁺e⁻ is observed for the first time, with a statistical significance of ...
    • Observation of Λ_c⁺ → nK_s⁰ π⁺ 

      Ablikim, M.; Achasov, M. N.; Ahmed, S.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Lou, Xinchou (American Physical Society, 2018-05-24)
      We report the first direct measurement of decays of the Λ_c⁺ baryon involving the neutron. The analysis is performed using 567 pb⁻¹ of e⁺e⁻ collision data collected at √s̅ = 4.599 GeV with the BESIII detector at the BEPCII ...
    • Observation of ψ(3686) → e⁺e⁻χ_{cJ} and χ_{cJ} → e⁺e⁻J/ψ 

      Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Amoroso, A.; Lou, Xinchou; BESIII Collaboration (American Physical Society, 2017)
      Using 4.479 x 10⁸ ψ(3686) events collected with the BESIII detector, we search for the decays ψ(3686)→ e⁺e⁻χ_{cJ} and χ_{cJ} → e⁺e⁻J/ψ, where J=0, 1, 2. The decays ψ(3686) → e⁺e⁻χ_{cJ} and χ_{cJ} → e⁺e⁻J/ψ are observed for ...
    • Observational Evidence of the Drift-Mirror Plasma Instability in Earth's Inner Magnetosphere 

      Soto-Chavez, A. R.; Lanzerotti, L. J.; Manweiler, J. W.; Gerrard, A.; Cohen, R.; Xia, Zhiyang; Chen, Lunjin; Kim, H.
      We report on evidence for the generation of an ultra-low frequency plasma wave by the drift-mirror plasma instability in the dynamic plasma environment of Earth's inner magnetosphere. The plasma measurements are obtained ...
    • Observations of Discrete Harmonics Emerging from Equatorial Noise 

      Balikhin, Michael A.; Shprits, Yuri Y.; Walker, Simon N.; Chen, Lunjin; Cornilleau-Wehrlin, Nicole; Dandouras, Iannis; Santolik, Ondrej; Carr, Christopher; Yearby, Keith H.; Weiss, Benjamin (Nature Publishing Group, 2015-07-14)
      A number of modes of oscillations of particles and fields can exist in space plasmas. Since the early 1970s, space missions have observed noise-like plasma waves near the geomagnetic equator known as 'equatorial noise'. ...
    • Observations of the Generation of Eastward Equatorial Electric Fields near Dawn 

      Kelley, M. C.; Rodrigues, Fabiano S.; Pfaff, R. F.; Klenzing, J. (Copernicus Gesellschaft Mbh, 2014-09-19)
      We report and discuss interesting observations of the variability of electric fields and ionospheric densities near sunrise in the equatorial ionosphere made by instruments onboard the Communications/Navigation Outage ...
    • Observations while attempting to fabricate a micro-electron detection system 

      Hernandez, Keith Valdez (2016-12)
      Over the past 20 years, Micro-Electromechanical Systems (MEMS) influence typical daily activities and have become integrated in everyday life. Fabrication of such devices on the micro- and nano-scale is made possible with ...
    • Observer-Based Feedback Controllers for Exponential Stabilization of Hybrid Periodic Orbits: Application to Underactuated Bipedal Walking 

      Hamed, K. A.; Ames, A. D.; Gregg, Robert D.
      This paper presents a systematic approach to design observer-based output feedback controllers for hybrid dynamical systems arising from bipedal walking. We consider a class of parameterized observer-based output feedback ...
    • Observing Cascade Behavior Depending on the Network Topology and Transaction Costs 

      Kim, Joohyun; Kwon, Ohsung; Lee, Duk Hee (Springer, 2019-01-31)
      The Internet, smartphones, Social Networking Service, and other IT goods have improved the overall quality of life, but created an over-connectedness with extremely low transaction costs in our society, amplifying latent ...