838 research outputs found

    Associated Production of Neutral Higgs Boson with Squark Pair in the Minimal Supersymmetric Standard Model with Explicit CP Violation at the CERN LHC

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    We investigate the associated production of neutral Higgs boson with squark pair in the minimal supersymmetric standard model with and without explicit CP violation, respectively. We show that the dominant productions in both cases are always ones of the lightest neutral Higgs boson associated with the lightest stop pair, which can reach a few pb, in the ranges of parameters allowed by constraints from the electric dipole moment experiments. In most of the parameter space, the total cross sections in the case with explicit CP violation are significantly enhanced, compared with ones without explicit CP violation. For some special parameters, several orders of magnitude enhancement can be obtained.Comment: 4 pages, 7 figures, version to appear in PR

    Updated predictions for graviton and photon associated production at the LHC

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    We present updated predictions on the inclusive total cross sections, including the complete next-to-leading order QCD corrections, for the graviton and photon associated production process in the large extra dimensions model at the LHC with a center-of-mass energy of 7 and 8 TeV, using the parameters according to the requirements of the ATLAS and CMS Collaborations. Moreover, we also discuss in detail the dependence on the transverse momentum cut and uncertainties due to the choices of scales and parton distribution functions.Comment: 5 pages, 3 figures, 2 tables, version published in PR

    Top-squark mixing effects in the supersymmetric electroweak corrections to top quark production at the Tevatron

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    Taking into account the mixing effects between left- and right-handed top-squarks, we calculate the genuine supersymmetric eletroweak correction to top quark production at the Tevatron in the minimal supersymmetric model. The analytic expressions of the corrections to both the parton level cross section and the total hadronic cross section are presented. Some numerical examples are also given to show the size of the corrections.Comment: 11 pages, 3 figures, available at reques

    Probing the baryogenesis and dark matter relaxed in phase transition by gravitational waves and colliders

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    The cosmological phase transition with Q-balls production mechanism can explain the baryogenesis and dark matter simultaneously, where constraints on dark matter masses and reverse dilution are significantly relaxed. We study how to probe this scenario by collider signals at QCD next-to-leading order and gravitational wave signals.Comment: 22 pages,9 figures,4 tables, published in Phys.Rev.

    Electroweak baryogenesis in the framework of the effective field theory

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    We study the electroweak baryogenesis in the framework of the effective field theory. Our study shows that by introducing a light singlet scalar particle and a dimension-5 operator, it can provide the strong first order phase transition and the source of the CP-violation during the phase transition, and then produce abundant particle phenomenology at zero temperature. We also show the constraints on the new physics scale from the observed baryon-to-photon ratio, the low-energy experiments, and the LHC data.Comment: 12 pages, 5 figures, 1 table; version published in Phys.Rev.

    Renormalization group improved predictions for ttˉW±t\bar{t}W^\pm production at hadron colliders

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    We study the factorization and resummation of the ttˉW±t\bar{t}W^\pm production at hadron colliders. The cross section in the threshold limit can be factorized into a convolution of hard and soft functions and parton distribution functions with the soft-collinear effective theory. We calculate the next-to-leading order soft function for the associated production of the heavy quark pair and colorless particle, and we perform the resummation calculation with the next-to-next-to-leading logarithms accuracy. Our results show that the resummation effects reduce the dependence of the cross section on the scales significantly and increase the total cross section by 713%7-13\% compared with NLO QCD results.Comment: 23 pages, 7 figures and 2 tables; final version in PR

    Next-to-leading order QCD predictions for associated production of top squarks and charginos at the CERN LHC

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    We present the calculations of the complete next-to-leading order (NLO) inclusive total cross sections for the associated production processes ppt~iχ~k+Xpp\to \tilde{t}_i\tilde{\chi}_k^-+X in the Minimal Supersymmetric Standard Model at the CERN Large Hadron Collider. Our calculations show that the total cross sections for the t~1χ~1\tilde{t}_1\tilde{\chi}_1^- production for the lighter top squark masses in the region 100 GeV <mt~1<< m_{\tilde{t}_1}< 160 GeV can reach 1 pb in the favorable parameter space allowed by the current precise experiments, and in other cases the total cross sections generally vary from 10 fb to several hundred fb except both mt~1>m_{\tilde{t}_1}> 500 GeV and the t~2χ~2\tilde{t}_2\tilde{\chi}_2^- production channel. Moreover, we find that the NLO QCD corrections in general enhance the leading order total cross sections significantly, and vastly reduce the dependence of the total cross sections on the renormalization/factorization scale, which leads to increased confidence in predictions based on these results.Comment: 42 pages, 13 figures, RevTex4. Journal-ref adde

    Higgs Boson Production via Gluon Fusion in the Standard Model with four Generations

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    Higgs bosons can be produced copiously at the LHC via gluon fusion induced by top and bottom quark loops, and can be enhanced strongly if extra heavy quarks exist. We present results for Higgs +zero-, one- and two-jet production at the LHC, in both the Standard Model and the 4th generation model, by evaluating the corresponding heavy quark triangle, box and pentagon Feynman diagrams. We compare the results by using the effective Higgs-gluon interactions in the limit of heavy quarks with the cross sections including the full mass dependences. NLO effects with full mass dependence are included in the inclusive Higgs boson production rate. Our results improve the theoretical basis for fourth generation effects on the Higgs boson search at the LHC.Comment: Published version in PR
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