1,401 research outputs found

    Search for the Anomalous Interactions of Up-Type Heavy Quarks in γγ\gamma \gamma Collision at the LHC

    Get PDF
    We investigate the anomalous interactions of heavy up-type quark t' in a γγ\gamma \gamma collision at the LHC. We have obtained 95% confidence level(CL)limit of t′qγt'q \gamma anomalous coupling by taking into account three forward detector acceptances: 0.0015<ξ<0.150.0015<\xi<0.15,0.0015<ξ<0.50.0015<\xi<0.5, and 0.1<ξ<0.50.1<\xi<0.5.Comment: 16 pages, 3 figures, 3 table

    Probe of the Anomalous Quartic Couplings with Beam Polarization at the CLIC

    Full text link
    We have investigated the anomalous quartic couplings defined by the dimension-8 operators in semileptonic decay channel of the e+e−→νeW−W+νˉee^{+}e^{-}\rightarrow \nu_{e} W^{-} W^{+} \bar{\nu}_{e} process for unpolarized and polarized electron (positron) beam at the Compact Linear Collider. We give the 95%95\% confidence level bounds on anomalous fS0Λ4\frac{f_{S0}}{\Lambda^{4}}, fS1Λ4\frac{f_{S1}}{\Lambda^{4}} and fT0Λ4\frac{f_{T0}}{\Lambda^{4}} couplings for various values of the integrated luminosities and center-of-mass energies. The best sensitivities obtained on anomalous fS0Λ4\frac{f_{S0}}{\Lambda^{4}}, fS1Λ4\frac{f_{S1}}{\Lambda^{4}} and fT0Λ4\frac{f_{T0}}{\Lambda^{4}} couplings through the process e+e−→νeW−W+νˉee^{+}e^{-}\rightarrow \nu_{e} W^{-} W^{+} \bar{\nu}_{e} with beam polarization at s=3\sqrt{s}=3 TeV and an integrated luminosity of Lint=2000L_{int}=2000 fb−1^{-1} are [−4.05; 3.67]×10−12[-4.05;\, 3.67]\times 10^{-12} GeV−4^{-4}, [−3.08; 2.12]×10−12[-3.08; \, 2.12]\times 10^{-12} GeV−4^{-4}, [−1.98; 0.64]×10−13[-1.98; \, 0.64]\times 10^{-13} GeV−4^{-4}, which show improvement over the current bounds.Comment: 8 pages, 7 figures and 8 tables, published versio

    The SGR 1806-20 magnetar signature on the Earth's magnetic field

    Full text link
    SGRs denote ``soft γ\gamma-ray repeaters'', a small class of slowly spinning neutron stars with strong magnetic fields. On 27 December 2004, a giant flare was detected from magnetar SGR 1806-20. The initial spike was followed by a hard-X-ray tail persisting for 380 s with a modulation period of 7.56 s. This event has received considerable attention, particularly in the astrophysics area. Its relevance to the geophysics community lies in the importance of investigating the effects of such an event on the near-earth electromagnetic environment. However, the signature of a magnetar flare on the geomagnetic field has not previously been investigated. Here, by applying wavelet analysis to the high-resolution magnetic data provided by the CHAMP satellite, a modulated signal with a period of 7.5 s over the duration of the giant flare appears in the observed data. Moreover, this event was detected by the energetic ion counters onboard the DEMETER satellite.Comment: Science Editors' Choice: http://www.sciencemag.org/content/vol314/issue5798/twil.dt

    Anomalous WWγWW\gamma couplings with beam polarization at the Compact Linear Collider

    Get PDF
    We study the anomalous WWγWW\gamma couplings at the Compact Linear Collider through the processes e+e−→W+W−e^{+}e^{-}\to W^+W^-, e−e+→e−γ∗e+→e+νeW−e^{-}e^{+} \to e^{-} \gamma^{*} e^{+} \to e^{+} \nu_{e} W^- and e−e+→e−γ∗γ∗e+→e−W+W−e+e^{-}e^{+}\to e^{-} \gamma^{*} \gamma^{*} e^{+} \to e^{-} W^+ W^- e^{+} (γ∗ (\gamma^{*} is the Weizsacker-Williams photon). We give the 95\% confidence level limits for unpolarized and polarized electron (positron) beam on the anomalous couplings for various values of the integrated luminosities and center-of-mass energies. We show that the obtained limits on the anomalous couplings through these processes can highly improve the current experimental limits. In addition, our limits with beam polarization are approximately two times better than the unpolarized case.Comment: Tables and references adde

    The effect of electromagnetic properties of neutrinos on the photon-neutrino decoupling temperature

    Full text link
    We examine the impact of electromagnetic properties of neutrinos on the annihilation of relic neutrinos with ultra high energy cosmic neutrinos for the ννˉ→γγ\nu \bar{\nu}\to \gamma\gamma process. For this process, photon-neutrino decoupling temperature is calculated via effective lagrangian model beyond the standard model. We find that photon-neutrino decoupling temperature can be importantly reduced below the QCD phase transition with the model independent analysis defining electromagnetic properties of neutrinos.Comment: 12 pages, 3 figures, published versio

    Comparisons of environmental effects and productivity by road construction machines in forest areas in Turkey

    Get PDF
    In this study, forest road construction techniques, environmental damages, cross sections and productivity by using hydraulic excavator and bulldozer were investigated in forested lands in Antalya and Eskisehir region in Turkey. Maximum length of fill slope for bulldozer and excavator were found 17 m on 80% slope gradient and 11 m on same slope gradient, respectively. The costs of forest roads for bulldozer and excavator were calculated to be 21.8 US dollars/m and 8.5 US dollars/m, respectively. Productivity of bulldozer and excavator were found to be 105.8 and 66.2 m3/h, respectively. The types of environmental damages on trees were determined and found to be wounded, bending and crushing. In this study, 23% of trees under the forest road construction by excavator are damaged and 40% of trees by bulldozer are damaged for 45 - 90% ground slope.Key words: Hydraulic excavator, bulldozer, forest road, road construction, environmental damage, construction cost

    The impact of excited neutrinos on ννˉ→γγ\nu \bar{\nu}\to \gamma\gamma process

    Get PDF
    We examine the effect of excited neutrinos on the annihilation of relic neutrinos with ultra high energy cosmic neutrinos for the ννˉ→γγ\nu \bar{\nu}\to \gamma\gamma process. The contribution of the excited neutrinos to the neutrino-photon decoupling temperature are calculated. We see that photon-neutrino decoupling temperature can be significantly reduced below the obtained value of the Standard Model with the impact of excited neutrinos.Comment: 11 pages, 3 figures, published versio
    • …
    corecore