21 research outputs found

    W-+ H+- production and CP asymmetry at the LHC

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    The dominant contributions to W-+ H+- production at the LHC are the tree-level b anti-b annihilation and the gg fusion. We perform for the case of the complex MSSM a complete calculation of the NLO EW corrections to the b anti-b annihilation channel and a consistent combination with other contributions including the standard and SUSY QCD corrections and the gg fusion, with resummation of the leading radiative corrections to the bottom-Higgs couplings and the neutral Higgs-boson propagators. We observe a large CP-violating asymmetry, arising mainly from the gg channel.Comment: 33 pages, 21 figures, a few typos corrected, one reference adde

    NLO electroweak corrections to doubly-polarized W+W−W^+W^- production at the LHC

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    We present new results of next-to-leading order (NLO) electroweak corrections to doubly-polarized cross sections of W+W−W^+W^- production at the LHC. The calculation is performed for the leptonic final state of e+μeμ−νˉμe^+\mu_e \mu^- \bar{\nu}_\mu using the double-pole approximation in the diboson center-of-mass frame. NLO QCD corrections and subleading contributions from the gggg, bbˉb\bar{b}, γγ\gamma\gamma induced processes are taken into account in the numerical results. We found that NLO EW corrections are small for angular distributions but can reach tens of percent for transverse momentum distributions at high energies, e.g. reaching −40%-40\% at pT,e≈300p_{T,e}\approx 300 GeV. In these high pTp_T regions, EW corrections are largest for the doubly-transverse mode.Comment: 15 pages, 1 table, 5 figure

    D0C : A code to calculate scalar one-loop four-point integrals with complex masses

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    We present a new Fortran code to calculate the scalar one-loop four-point integral with complex internal masses, based on the method of 't Hooft and Veltman. The code is applicable when the external momenta fulfill a certain physical condition. In particular it holds if one of the external momenta or a sum of them is timelike or lightlike and therefore covers all physical processes at colliders. All the special cases related to massless external particles are treated separately. Some technical issues related to numerical evaluation and Landau singularities are discussed.Comment: Version published in CP

    Nutritional status, feeding practice and incidence of infectious diseases among children aged 6 to 18 months in northern mountainous Vietnam

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    To assess the prevalence of undernutrition, incidence of infectious diseases and the situation of feeding practices to determine the risk factors for undernutrition among children aged 6 to 18 months in rural Vietnam. Design : A cross-sectional study was conducted among one hundred eighty-eight mother-child pairs in Bac Giang, Vietnam. Weight and height of the children were measured and referred to data from the WHO/CDC/NCHS. Incidence of infectious diseases was diagnosed based on the WHO Recommended Surveillance Standards. Data on socio-demographic variables and feeding practices were obtained through a structured questionnaire. Result : The prevalence of underweight, stunting and wasting was 19.7%, 23.4% and 5.3%, respectively. The incidence of diarrhea and acute respiratory infections (ARIs) during the last 14 days of the interview was 12.2% and 20.2%, respectively. Although 99% of the children were breastfed, the prevalence of exclusive breastfeeding in the first 4 mo was 21.3%. Non-exclusive breastfeeding in the first 4 month (OR 3.95, p=0.025) and low birth weight (OR 4.38, p=0.009) were associated with underweight in the children, while incidence of infectious disease was not (OR 1.16, p=0.734). Conclusion : Undernutrition is highly prevalent in the study site and non-exclusive breast feeding is one of the risk factors

    NLO electroweak corrections to doubly-polarized

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    We present new results of next-to-leading order (NLO) electroweak corrections to doubly-polarized cross sections of W+W−W^+W^- production at the LHC. The calculation is performed for the leptonic final state of e+μeμ−νˉμe^{+}\mu _{e} \mu ^{-} {\bar{\nu }}_{\mu } using the double-pole approximation in the diboson center-of-mass frame. NLO QCD corrections and subleading contributions from the gg, bbˉb{\bar{b}}, γγ\gamma \gamma induced processes are taken into account in the numerical results. We found that NLO EW corrections are small for angular distributions but can reach tens of percent for transverse momentum distributions at high energies, e.g. reaching −40%-40\% at pT,e≈300p_{T,e}\approx 300 GeV. In these high pTp_T regions, EW corrections are largest for the doubly-transverse mode

    Doubly-polarized

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    The doubly-polarized production of W±ZW^\pm Z pairs at the Large Hadron Collider (LHC) is presented at next-to-leading order (NLO) accuracy both for the electroweak (EW) and QCD corrections, including a detailed description of the calculational method using the double-pole approximation. Numerical results at the 13 TeV LHC are presented in particular for the W−ZW^- Z case in the e−νˉeμ+μ−e^-\bar{\nu }_e \mu ^+\mu ^- channel using ATLAS fiducial cuts and for polarized distributions defined in the WZ center-of-mass system. The NLO EW corrections relative to the NLO QCD predictions are found to be smaller than 5% in most kinematic distributions, but can reach the level of 10% in some distributions such as lepton transverse momentum distributions or rapidity separation between the electron and the Z boson. EW corrections are not uniform for different polarizations. A comparison between the new ATLAS measurement of polarization fractions to our theoretical prediction is presented

    Leptonic anomalous magnetic and electric dipole moments in the CP-violating NMSSM with and without inverse seesaw mechanism

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    The new results on the muon anomalous magnetic moment (AMM) published by Fermilab in 2021 did not lead to a reduction of its long-pending deviation from the Standard Model (SM) value by more than 4σ\sigma . The explanation of this discrepancy by adding new particles to the theory puts many new physics models under tension when combined with the null results of the LHC direct searches for new particles. In this paper, we investigate the CP-violating Next-to-Minimal Supersymmetric extension of the SM (NMSSM) with and without an inverse seesaw mechanism. We compute the one-loop supersymmetric contributions to the AMM and the two-loop Barr–Zee-type diagrams with effective Higgs couplings to photons for the leptonic electric dipole moments (EDMs). The effects of the extended (s)neutrino sector on the muon AMM and on the mass of the SM-like Higgs boson can be significant. Complex phases can have an important impact on the AMM. On the other hand, the stringent limits from the EDMs on the complex phases have to be taken into account. Our calculations have been implemented in the Fortran codes NMSSMCALC and NMSSMCALC-nuSS which are publicly available. Besides the leptonic AMMs and EDMs, these programs can compute the Higgs boson masses and mixings, together with Higgs boson decay widths and branching ratios taking into account the most up-to-date higher-order corrections in the NMSSM with and without inverse seesaw mechanism
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