3,400 research outputs found

    Two-photon width of the charmonium state X_(c2)

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    The two-photon width of X_(c2)^3P_2 state of charmonium has been measured using 14.4 fb^(-1) of e^+e^-data taken at √s =9.46–11.30 GeV with the CLEO III detector. The yy-fusion reaction studied is e^+e^- → e^+e^-yy, → yy X_(c2) → yJ/Ψ → ye^+e^-(µ^+µ^-). We measure Г_(yy) (X_(c2))B(X_(c2)) → y J/Ψ)B(J/Ψ → e^+e^- + µ^+µ^-)= 13.2 ± 1.4(stat)± 1.1(syst) eV, and obtain Г yy(Xc2)= 559 ± 57(stat) ± 48(syst) ± 36(br) eV. This result is in excellent agreement with the result of -fusion measurement by Belle and is consistent with that of the pp → X_(c2) → yy measurement, when they are both reevaluated using the recent CLEO result for the radiative decay X_(c2) → J/Ψ

    Observation of B_s Production at the Y(5S) Resonance

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    Using the CLEO detector at the Cornell Electron Storage Ring, we have observed the B_s meson in e^+e^- annihilation at the Υ(5S) resonance. We find 14 candidates consistent with B_s decays into final states with a J/ψ or a D_s^((*)-). The probability that we have observed a background fluctuation is less than 8×10^(-10). We have established that at the energy of the Υ(5S) resonance B_s production proceeds predominantly through the creation of B_s^*B̅ _s^* pairs. We find σ(e^+e^-→B^s^*B̅ ^*)=[0.11_(-0.03)^(+0.04)(stat)±0.02(syst)]  nb, and set the following limits: σ(e^+e^-→B_sB̅ _s)/σ(e^+e^-→B_s^*B̅ _s^*)<0.16 and [σ(e^+e^-→B_sB̅ _s^*)+σ(e^+e^-→B_s*B̅ _s)]/σ(e^+e^-→B_s*B̅ _s^*)<0.16 (90% C.L.). The mass of the B_s^* meson is measured to be M_(B_s^*=[5.414±0.001(stat)±0.003(syst)]  GeV/c^2

    Quantum Sensor Miniaturization

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    The classical bound on image resolution defined by the Rayleigh limit can be beaten by exploiting the properties of quantum mechanical entanglement. If entangled photons are used as signal states, the best possible resolution is instead given by the Heisenberg limit, an improvement proportional to the number of entangled photons in the signal. In this paper we present a novel application of entanglement by showing that the resolution obtained by an imaging system utilizing separable photons can be achieved by an imaging system making use of entangled photons, but with the advantage of a smaller aperture, thus resulting in a smaller and lighter system. This can be especially valuable in satellite imaging where weight and size play a vital role.Comment: 3 pages, 1 figure. Accepted for publication in Photonics Technology Letter

    Matching of analytical and numerical solutions for neutron stars of arbitrary rotation

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    We demonstrate the results of an attempt to match the two-soliton analytical solution with the numerically produced solutions of the Einstein field equations, that describe the spacetime exterior of rotating neutron stars, for arbitrary rotation. The matching procedure is performed by equating the first four multipole moments of the analytical solution to the multipole moments of the numerical one. We then argue that in order to check the effectiveness of the matching of the analytical with the numerical solution we should compare the metric components, the radius of the innermost stable circular orbit (RISCOR_{ISCO}), the rotation frequency Ωdϕdt\Omega\equiv\frac{d\phi}{dt} and the epicyclic frequencies Ωρ,  Ωz\Omega_{\rho},\;\Omega_z. Finally we present some results of the comparison.Comment: Contribution at the 13th Conference on Recent Developments in Gravity (NEB XIII), corrected typo in M4M_4 of eq. 5 of the published versio

    Quantitation of buried contamination by use of solvents

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    Experiments directed at determining the potential of reclaimed silicone polymers for reuse are described

    Quantitation of buried contamination by use of solvents

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    Spore recovery form cured silicone potting compounds using amine solvents to degrade the cured polymers was investigated. A complete list of solvents and a description of the effect of each on two different silicone polymers is provided

    Identifying capacitive and inductive loss in lumped element superconducting hybrid titanium nitride/aluminum resonators

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    We present a method to systematically locate and extract capacitive and inductive losses in superconducting resonators at microwave frequencies by use of mixed-material, lumped element devices. In these devices, ultra-low loss titanium nitride was progressively replaced with aluminum in the inter-digitated capacitor and meandered inductor elements. By measuring the power dependent loss at 50 mK as the Al-TiN fraction in each element is increased, we find that at low electric field, i.e. in the single photon limit, the loss is two level system in nature and is correlated with the amount of Al capacitance rather than the Al inductance. In the high electric field limit, the remaining loss is linearly related to the product of the Al area times its inductance and is likely due to quasiparticles generated by stray radiation. At elevated temperature, additional loss is correlated with the amount of Al in the inductance, with a power independent TiN-Al interface loss term that exponentially decreases as the temperature is reduced. The TiN-Al interface loss is vanishingly small at the 50 mK base temperature.Comment: 10 pages, 5 figure

    Characterization and In-situ Monitoring of Sub-stoichiometric Adjustable Tc Titanium Nitride Growth

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    The structural and electrical properties of Ti-N films deposited by reactive sputtering depend on their growth parameters, in particular the Ar:N2 gas ratio. We show that the nitrogen percentage changes the crystallographic phase of the film progressively from pure \alpha-Ti, through an \alpha-Ti phase with interstitial nitrogen, to stoichiometric Ti2N, and through a substoichiometric TiNX to stoichiometric TiN. These changes also affect the superconducting transition temperature, Tc, allowing, the superconducting properties to be tailored for specific applications. After decreasing from a Tc of 0.4 K for pure Ti down to below 50 mK at the Ti2N point, the Tc then increases rapidly up to nearly 5 K over a narrow range of nitrogen incorporation. This very sharp increase of Tc makes it difficult to control the properties of the film from wafer-to-wafer as well as across a given wafer to within acceptable margins for device fabrication. Here we show that the nitrogen composition and hence the superconductive properties are related to, and can be determined by, spectroscopic ellipsometry. Therefore, this technique may be used for process control and wafer screening prior to investing time in processing devices

    Remote Sensing and Control of Phase Qubits

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    We demonstrate a remote sensing design of phase qubits by separating the control and readout circuits from the qubit loop. This design improves measurement reliability because the control readout chip can be fabricated using more robust materials and can be reused to test different qubit chips. Typical qubit measurements such as Rabi oscillations, spectroscopy, and excited-state energy relaxation are presented.Comment: 3 pages, 4 figure
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