6,992 research outputs found

    Ultrastable Optical Clock with Neutral Atoms in an Engineered Light Shift Trap

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    An ultrastable optical clock based on neutral atoms trapped in an optical lattice is proposed. Complete control over the light shift is achieved by employing the 5s21S0→5s5p3P05s^2 {}^1S_0 \to 5s5p {}^3P_0 transition of 87Sr{}^{87}{\rm Sr} atoms as a "clock transition". Calculations of ac multipole polarizabilities and dipole hyperpolarizabilities for the clock transition indicate that the contribution of the higher-order light shifts can be reduced to less than 1 mHz, allowing for a projected accuracy of better than 10−17 10^{-17}.Comment: 4 pages, 2 figures, accepted for publication in Phys. Rev. Let

    Atypical Interstitial Pneumonia in the Bovine

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    On August 5, 1980, a dead 950 pound steer was submitted to the Iowa Veterinary Diagnostic Laboratory for necropsy (IVDL Case 18274). The history included acute dyspnea, raspy cough, a temperature of 40.5-41.7 C (105-107 F) in 20 out of 125 animals and two death.s These cattle had been purchased on July 17, 1980 and first noticed sick on August 4, 1980. The tentative diagnoses were Hemophilus pneumonia and viral pneumonia. Treatment included intravenous tetrayccline and intramuscular penicillin and resulted in a fairly good response

    Pixel Detectors for Charged Particles

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    Pixel Detectors, as the current technology of choice for the innermost vertex detection, have reached a stage at which large detectors have been built for the LHC experiments and a new era of developments, both for hybrid and for monolithic or semi-monolithic pixel detectors is in full swing. This is largely driven by the requirements of the upgrade programme for the superLHC and by other collider experiments which plan to use monolithic pixel detectors for the first time. A review on current pixel detector developments for particle tracking and vertexing is given, comprising hybrid pixel detectors for superLHC with its own challenges in radiation and rate, as well as on monolithic, so-called active pixel detectors, including MAPS and DEPFET pixels for RHIC and superBelle.Comment: 19 pages, 23 drawings in 14 figure

    Evidence for a breakdown of the Isobaric Multiplet Mass Equation: A study of the A=35, T=3/2 isospin quartet

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    Mass measurements on radionuclides along the potassium isotope chain have been performed with the ISOLTRAP Penning trap mass spectrometer. For 35K T1/2=178ms) to 46K (T1/2=105s) relative mass uncertainties of 2x10-8 and better have been achieved. The accurate mass determination of 35K (dm=0.54keV) has been exploited to test the Isobaric Multiplet Mass Equation (IMME) for the A=35, T=3/2 isospinquartet. The experimental results indicate a deviation from the generally adopted quadratic form.Comment: 8 pages, 4 figure
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