183 research outputs found

    Perturbative renormalization factors for generic Δs=2\Delta s=2 four-quark operators in domain-wall QCD with improved gauge action

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    We calculate one-loop renormalization factors of generic DeltaS=2 four-quark operators for domain-wall QCD with the plaquette gauge action and the Iwasaki gauge action. The renormalization factors are presented in the modified minimal subtraction (MS-bar) scheme with the naive dimensional regularization. As an important application we show how to construct the renormalization factors for the operators contributing to K^0-K^0bar mixing in the supersymmetric models with the use of our results.Comment: 22 pages,uses revtex

    Precise determination of BKB_K and light quark masses in quenched domain-wall QCD

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    We calculate non-perturbative renormalization factors at hadronic scale for ΔS=2\Delta S=2 four-quark operators in quenched domain-wall QCD using the Schr\"{o}dinger functional method. Combining them with the non-perturbative renormalization group running by the Alpha collaboration, our result yields the fully non-perturbative renormalization factor, which converts the lattice bare BKB_K to the renormalization group invariant (RGI) B^K\hat{B}_K. Applying this to the bare BKB_K previously obtained by the CP-PACS collaboration at a12,3,4a^{-1}\simeq 2, 3, 4 GeV, we obtain B^K=0.782(5)(7)\hat{B}_K=0.782(5)(7) (equivalent to BKMSˉ(NDR,2GeV)=0.565(4)(5)B_K^{\bar{\rm MS}}({\rm NDR}, 2 {\rm GeV}) = 0.565(4)(5) by 2-loop running) in the continuum limit, where the first error is statistical and the second is systematic due to the continuum extrapolation. Except the quenching error, the total error we have achieved is less than 2%, which is much smaller than the previous ones. Taking the same procedure, we obtain mu,dRGI=5.613(66)m_{u,d}^{\rm RGI}=5.613(66) MeV and msRGI=147.1(17)m_s^{\rm RGI}=147.1(17) MeV (equivalent to mu,dMSˉ(2GeV)=4.026(48)m_{u,d}^{\bar{\rm MS}}(2 {\rm GeV})=4.026(48) MeV and msMSˉ(2GeV)=105.6(12)m_{s}^{\bar{\rm MS}}(2 {\rm GeV})=105.6(12) MeV by 4-loop running) in the continuum limit.Comment: 51 pages, 27 Postscript figures, corrected typos, added referenc

    Pre-DECIGO can get the smoking gun to decide the astrophysical or cosmological origin of GW150914-like binary black holes

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    Pre-DECIGO consists of three spacecraft arranged in an equilateral triangle with 100km arm lengths orbiting 2000km above the surface of the earth. It is hoped that the launch date will be in the late 2020s. Pre-DECIGO has one clear target: binary black holes (BBHs) like GW150914 and GW151226. Pre-DECIGO can detect 30M30M\sim 30M_\odot-30M_\odot BBH mergers up to redshift z30z\sim 30. The cumulative event rate is 1.8×105events yr1\sim 1.8\times 10^{5}\,{\rm events~yr^{-1}} in the Pop III origin model of BBHs like GW150914, and it saturates at z10z\sim 10, while in the primordial BBH (PBBH) model, the cumulative event rate is 3×104events yr1 \sim 3\times 10^{4}\,{\rm events~ yr^{-1}} at z=30z=30 even if only 0.1%0.1\% of the dark matter consists of PBHs, and it is still increasing at z=30z=30. In the Pop I/II model of BBHs, the cumulative event rate is (310)×105events yr1(3-10)\times10^{5}\,{\rm events~ yr^{-1}} and it saturates at z6z \sim 6. We present the requirements on orbit accuracy, drag free techniques, laser power, frequency stability, and interferometer test mass. For BBHs like GW150914 at 1Gpc, SNR90\sim 90 is achieved with the definition of Pre-DECIGO in the 0.011000.01-100Hz band. Pre-DECIGO can measure the mass spectrum and the zz-dependence of the merger rate to distinguish various models of BBHs like GW150914. Pre-DECIGO can also predict the direction of BBHs at z=0.1z=0.1 with an accuracy of 0.3deg2\sim 0.3\,{\rm deg}^2 and a merging time accuracy of 1\sim 1s at about a day before the merger so that ground-based GW detectors further developed at that time as well as electromagnetic follow-up observations can prepare for the detection of merger in advance. For intermediate mass BBHs at a large redshift z>10z > 10, the QNM frequency after the merger can be within the Pre-DECIGO band so that the ringing tail can also be detectable to confirm the Einstein theory of general relativity with SNR35\sim 35. [abridged]Comment: 17 pages, 10 figures, added some references, modifications to match the published version in PTE

    Laparoscopic Partial Hepatectomy: Animal Experiments

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    As a first step in firmly establishing laparoscopic hepatectomy, we introduce a porcine model of laparoscopic partial hepatectomy. This procedure has been successfully performed under the normal-pressure or low-pressure pneumoperitoneum condition supported by the full-thickness abdominal wall lifting technique. An ultrasonic dissector combined with electrocautery, newly developed by Olympus Optical Corporation (Japan) was effectively utilized in facilitating safe and smooth incisions into the liver parenchyma. Although indications for this procedure seem to be limited only to peripheral lesions and not to central lesions, clinical application of this method may be useful for some patients in the near future

    Portable Electrochemical Gas Sensing System with a Paper-Based Enzyme Electrode

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    An unconventional portable electrochemical gas sensor composed of a smartphone, a finger-sized sensing chip and a single use paper-based enzyme electrode was proposed to detect a particular target gaseous inclusion for self-breath-analysis with ease. This attempt allowed us to monitor our physical status immediately and continuously regardless of a time, place or person due to the improved convenience, immediacy, and affordability. The custom CMOS chip with the capability of performing an amperometric determination when the power voltage supplied from the earphone jack of a smartphone was designed as an analytical device. A disposable enzyme electrode was prepared simply from a chromatography paper and a commercial carbon pencil instead of the conventional indisposable material and complex manufacturing process. The quantification of ethanol in gaseous samples was demonstrated in range from 50 to 500ppm (V/V) in accord with concentrations in exhaled breath. The response current increased linearly with increasing vapor ethanol concentration
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