894 research outputs found

    Loop effects and non-decoupling property of SUSY QCD in gb→tH−g b\to tH^{-}

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    One-loop SUSY QCD radiative correction to gb→tH−gb \to tH^{-} cross section is calculated in the Minimal Supersymmetric Standard Model. We found that SUSY QCD is non-decoupling if the gluino mass and the parameter ÎŒ\mu, AtA_t or AbA_b are at the same order and get large. The non-decoupling contribution can be enhanced by large tan⁥ÎČ\tan\beta and therefore large corrections to the hadronic production rates at the Tevatron and LHC are expected in the large tan⁥ÎČ\tan\beta limit. The fundamental reason for such non-decoupling behavior is found to be some couplings in the loops being proportional to SUSY mass parameters.Comment: 15 pages, 5 PS figures. A proof of non-decouplings of SUSY-QCD, Comments on corresponding QCD correction and references adde

    In vitro selection of salt-tolerant Ailanthus altissimaSwingle

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    Salt-tolerant cell lines of Ailanthus altissima were selected from callus derived protoplasts. Murashige–Skoog (MS) liquid medium incorporated with various concentrations of NaCl was employed to enrich salt-tolerant A. altissima cell lines. Salt-resistant A. altissima cells were transferred on MS solid medium supplemented with 2.5 ÎŒM 2,4-dichlorophenoxy acetic acid (2,4-D), 0.5 ÎŒM benzyl adenine (BA) and various NaCl concentrations. The callus was cultured on MS medium containing NaCl for 5 months, to determine the survival rate as an index of salt tolerance. The measurement of growth parameters for salt-tolerant cells showed that the selected plant cell lines grew better than the unselected ones at all levels of NaCl tested. The salt-tolerant callus accumulated proline in correlation to the concentration of salts. Media supplemented with BA induced shoot differentiation of salt-resistant A. altissima cells

    Josephson effect test for triplet pairing symmetry

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    The critical current modulation and the spontaneous flux of the vortex states in corner Josephson junctions between Sr2_2RuO4_4 and a conventional s-wave superconductor are calculated as a function of the crystal orientation, and the magnetic field. For Sr2_2RuO4_4 we assume two nodeless p-wave pairing states. Also we use the nodal ff-wave states B1g×EuB_{1g}\times E_u and B2g×EuB_{2g} \times E_u, and one special p-wave state having line nodes. It is seen that the critical current depends solely on the topology of the gap.Comment: 22 pages, 12 figure

    Virtual Effects of Split SUSY in Higgs Productions at Linear Colliders

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    In split supersymmetry the gauginos and higgsinos are the only supersymmetric particles possibly accessible at foreseeable colliders like the CERN Large Hadron Collider (LHC) and the International Linear Collider (ILC). In order to account for the cosmic dark matter measured by WMAP, these gauginos and higgsinos are stringently constrained and could be explored at the colliders through their direct productions and/or virtual effects in some processes. The clean environment and high luminosity of the ILC render the virtual effects of percent level meaningful in unraveling the new physics effects. In this work we assume split supersymmetry and calculate the virtual effects of the WMAP-allowed gauginos and higgsinos in Higgs productions e+e- -> Z h and e+e- -> \nu_e \bar_\nu_e h through WW fusion at the ILC. We find that the production cross section of e+e- -> Zh can be altered by a few percent in some part of the WMAP-allowed parameter space, while the correction to the WW-fusion process e+e- -> \nu_e \bar_\nu_e h is below 1%. Such virtual effects are correlated with the cross sections of chargino pair productions and can offer complementary information in probing split supersymmetry at the colliders.Comment: more discussions added (7 pages, 10 figs

    Supersymmetric effects in top quark decay into polarized W-boson

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    We investigate the one-loop supersymmetric QCD (SUSY-QCD) and electroweak (SUSY-EW) corrections to the top quark decay into a b-quark and a longitudinal or transverse W-boson. The corrections are presented in terms of the longitudinal ratio \Gamma(t-->W_L b)/\Gamma(t--> W b) and the transverse ratio \Gamma(t-->W_- b)/\Gamma(t--> W b). In most of the parameter space, both SUSY-QCD and SUSY-EW corrections to these ratios are found to be less than 1% in magnitude and they tend to have opposite signs. The corrections to the total width \Gamma(t-->W b) are also presented for comparison with the existing results in the literature. We find that our SUSY-EW corrections to the total width differ significantly from previous studies: the previous studies give a large correction of more than 10% in magnitude for a large part of the parameter space while our results reach only few percent at most.Comment: Version in PRD (explanation and refs added

    Supersymmetric Electroweak Corrections to Charged Higgs Boson Production in Association with a Top Quark at Hadron Colliders

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    We calculate the O(αewmt(b)2/mW2)O(\alpha_{ew}m_{t(b)}^{2}/m_{W}^{2}) and O(αewmt(b)4/mW4)O(\alpha_{ew} m_{t(b)}^4/m_W^4) supersymmetric electroweak corrections to the cross section for the charged Higgs boson production in association with a top quark at the Tevatron and the LHC. These corrections arise from the quantum effects which are induced by potentially large Yukawa couplings from the Higgs sector and the chargino-top(bottom)-sbottom(stop) couplings, neutralino-top(bottom)-stop(sbottom) couplings and charged Higgs-stop-sbottom couplings. They can decrease or increase the cross section depending on tan⁥ÎČ\tan\beta but are not very sensitive to the mass of the charged Higgs boson for high tan⁥ÎČ\tan\beta. At low tan⁥ÎČ(=2)\tan\beta(=2) the corrections decrease the total cross sections significantly, which exceed -12% for mH±m_{H^{\pm}} below 300GeV300GeV at both the Tevatron and the LHC, but for mH±>300GeVm_{H^{\pm}}>300GeV the corrections can become very small at the LHC. For high tan⁥ÎČ(=10,30)\tan\beta(=10,30) these corrections can decrease or increase the total cross sections, and the magnitude of the corrections are at most a few percent at both the Tevatron and the LHC.Comment: 28 pages including 4 eps figure

    Search for Invisible Decays of η\eta and ηâ€Č\eta^\prime in J/ψ→ϕηJ/\psi \to \phi\eta and ϕηâ€Č\phi \eta^\prime

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    Using a data sample of 58×10658\times 10^6 J/ψJ/\psi decays collected with the BES II detector at the BEPC, searches for invisible decays of η\eta and ηâ€Č\eta^\prime in J/ψJ/\psi to ϕη\phi\eta and ϕηâ€Č\phi\eta^\prime are performed. The ϕ\phi signals, which are reconstructed in K+K−K^+K^- final states, are used to tag the η\eta and ηâ€Č\eta^\prime decays. No signals are found for the invisible decays of either η\eta or ηâ€Č\eta^\prime, and upper limits at the 90% confidence level are determined to be 1.65×10−31.65 \times 10^{-3} for the ratio B(η→invisible)B(η→γγ)\frac{B(\eta\to \text{invisible})}{B(\eta\to\gamma\gamma)} and 6.69×10−26.69\times 10^{-2} for B(ηâ€Č→invisible)B(ηâ€Č→γγ)\frac{B(\eta^\prime\to \text{invisible})}{B(\eta^\prime\to\gamma\gamma)}. These are the first searches for η\eta and ηâ€Č\eta^\prime decays into invisible final states.Comment: 5 pages, 4 figures; Added references, Corrected typo

    Long-term trends in tropical cyclone tracks around Korea and Japan in late summer and early fall

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    This study investigates long-term trends in tropical cyclones (TCs) over the extratropical western North Pacific (WNP) over a period of 35 years (1982-2016). The area analyzed extended across 30-45 degrees N and 120-150 degrees E, including the regions of Korea and Japan that were seriously affected by TCs. The northward migration of TCs over the WNP to the mid-latitudes showed a sharp increase in early fall. In addition, the duration of TCs over the WNP that migrated northwards showed an increase, specifically in early to mid-September. Therefore, more recently, TC tracks have been observed to significantly extend into the mid-latitudes. The recent northward extension of TC tracks over the WNP in early fall was observed to be associated with changes in environmental conditions that were favorable for TC activities, including an increase in sea surface temperature (SST), decrease in vertical wind shear, expansion of subtropical highs, strong easterly steering winds, and an increase in relative vorticity. In contrast, northward migrations of TCs to Korea and Japan showed a decline in late August, because of the presence of unfavorable environmental conditions for TC activities. These changes in environmental conditions, such as SST and vertical wind shear, can be partially associated with the Pacific decadal oscillation

    Prospects for heavy supersymmetric charged Higgs boson searches at hadron colliders

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    We investigate the production of a heavy charged Higgs boson at hadron colliders within the context of the MSSM. A detailed study is performed for all important production modes and basic background processes for the t\bar{t}b\bar{b} signature. In our analysis we include effects of initial and final state showering, hadronization, and principal detector effects. For the signal production rate we include the leading SUSY quantum effects at high \tan\beta>~ mt/mb. Based on the obtained efficiencies for the signal and background we estimate the discovery and exclusion mass limits of the charged Higgs boson at high values of \tan\beta. At the upgraded Tevatron the discovery of a heavy charged Higgs boson (MH^+ >~ 200 GeV) is impossible for the tree-level cross-section values. However, if QCD and SUSY effects happen to reinforce mutually, there are indeed regions of the MSSM parameter space which could provide 3\sigma evidence and, at best, 5\sigma charged Higgs boson discovery at the Tevatron for masses M_H^+<~ 300 GeV and M_H^+<~ 250 GeV, respectively, even assuming squark and gluino masses in the (500-1000) GeV range. On the other hand, at the LHC one can discover a H^+ as heavy as 1 TeV at the canonical confidence level of 5\sigma; or else exclude its existence at 95% C.L. up to masses ~ 1.5 TeV. Again the presence of SUSY quantum effects can be very important here as they may shift the LHC limits by a few hundred GeV.Comment: Latex2e, 44 pages, 15 figures, 6 tables, uses JHEP3.sty, axodraw.sty. Comments added. Discussion on QCD factors clarified. Added discussion on uncertainties. Change of presentation of Tables 4 and 5 and Fig.6. Results and conclusions unchanged. Version accepted in JHE

    The flavor-changing bottom-strange quark production in the littlest Higgs model with T parity at the ILC

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    In the littlest Higgs model with T-parity (LHT) the mirror quarks induce the special flavor structures and some new flavor-changing (FC) couplings which could greatly enhance the production rates of the FC processes. We in this paper study some bottom and anti-strange production processes in the LHT model at the International Linear Collider (ILC), i.e., e+e−→bsˉe^+e^-\rightarrow b\bar{s} and γγ→bsˉ\gamma\gamma\rightarrow b\bar{s}. The results show that the production rates of these processes are sizeable for the favorable values of the parameters. Therefore, it is quite possible to test the LHT model or make some constrains on the relevant parameters of the LHT through the detection of these processes at the ILC.Comment: 12 pages, 8 figure
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