3,946 research outputs found

    Neutral Higgs production at proton colliders in the CP-conserving NMSSM

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    We discuss neutral Higgs boson production through gluon fusion and bottom-quark annihilation in the CP-conserving Z3\mathbb{Z}_3-invariant Next-to-Minimal Supersymmetric Standard Model (NMSSM) at proton colliders. For gluon fusion we adapt known asymptotic expansions in supersymmetric particles for the inclusion of next-to-leading order contributions of squarks and gluinos from the Minimal Supersymmetric Standard Model (MSSM) and include electro-weak corrections involving light quarks. Together with the resummation of higher order sbottom contributions in the bottom-quark Yukawa coupling for both production processes we thus present accurate cross section predictions implemented in a new release of the code SusHi. We elaborate on the new features of an additional SU(2)L(2)_L singlet in the production of CP-even and -odd Higgs bosons with respect to the MSSM and include a short discussion of theory uncertainties.Comment: 33 pages, 8 figures; minor corrections, updated references, matches published versio

    Off-shell effects in Higgs decays to heavy gauge bosons and signal-background interference in Higgs decays to photons at a linear collider

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    We discuss off-shell contributions in Higgs decays to heavy gauge bosons HVV()H\rightarrow VV^{(*)} with V{Z,W}V\in\lbrace Z,W\rbrace for a standard model (SM) Higgs boson for both dominant production processes e+eZHZVV()e^+e^-\rightarrow ZH\rightarrow ZVV^{(*)} and e+eννˉHννˉVV()e^+e^-\rightarrow \nu\bar\nu H\rightarrow \nu\bar\nu VV^{(*)} at a (linear) e+ee^+e^- collider. Dependent on the centre-of-mass energy off-shell effects are sizable and important for the understanding of the electroweak symmetry breaking mechanism. Moreover we shortly investigate the effects of the signal-background interference in HγγH\rightarrow \gamma\gamma decays for the Higgsstrahlung initiated process e+eZγγe^+e^-\rightarrow Z\gamma\gamma, where we report a similar shift in the invariant mass peak of the two photons as found for the LHC. For both effects we discuss the sensitivity to the total Higgs width.Comment: 11 pages, 9 figures, talk presented at the International Workshop on Future Linear Colliders (LCWS14), Belgrade, Serbia, 6-10 October 201

    CP violation in bilinear R-parity violation and its consequences for the early universe

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    Supersymmetric models with bilinear R-parity violation (BRpV) provide a framework for neutrino masses and mixing angles to explain neutrino oscillation data. We consider CP violation within the new physical phases in BRpV and discuss their effect on the generation of neutrino masses and the decays of the lightest supersymmetric particle (LSP), being a light neutralino with mass 100\sim 100 GeV, at next-to-leading order. The decays affect the lepton and via sphaleron transitions the baryon asymmetry in the early universe. For a rather light LSP, asymmetries generated before the electroweak phase transition via e.g. the Affleck-Dine mechanism are reduced up to two orders of magnitude, but are still present. On the other hand, the decays of a light LSP themselves can account for the generation of a lepton and baryon asymmetry, the latter in accordance to the observation in our universe, since the smallness of the BRpV parameters allows for an out-of-equilibrium decay and sufficiently large CP violation is possible consistent with experimental bounds from the non-observation of electric dipole-moments.Comment: 26 pages, 13 figure

    Phenomenology of on-shell Higgs production in the MSSM with complex parameters

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    A computation of inclusive cross sections for neutral Higgs boson production through gluon fusion and bottom-quark annihilation is presented in the MSSM with complex parameters. The predictions for the gluon-fusion process are based on an explicit calculation of the leading-order cross section for arbitrary complex parameters which is supplemented by higher-order corrections: massive top- and bottom-quark contributions at NLO QCD, in the heavy top-quark effective theory the top-quark contribution up to N3^3LO QCD including a soft expansion for the CP\mathcal{CP}-even component of the light Higgs boson. For its CP\mathcal{CP}-odd component and the heavy Higgs bosons the contributions are incorporated up to NNLO QCD. Two-loop electroweak effects are also incorporated, and SUSY QCD corrections at NLO are interpolated from the MSSM with real parameters. Finite wave function normalisation factors ensuring correct on-shell properties of the external Higgs bosons are incorporated from the code FeynHiggs\texttt{FeynHiggs}. For the typical case of a strong admixture of the two heavy Higgs bosons it is demonstrated that squark effects are strongly dependent on the phases of the complex parameters. The remaining theoretical uncertainties for cross sections are discussed. The results have been implemented into an extension of the numerical code SusHi\texttt{SusHi} called SusHiMi\texttt{SusHiMi}.Comment: 37 pages, 12 figures, minor clarifications, updated references, matches published versio

    Interference contributions to gluon initiated heavy Higgs production in the Two-Higgs-Doublet Model

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    We discuss the production of a heavy neutral Higgs boson of a CP-conserving Two-Higgs-Doublet Model in gluon fusion and its decay into a four-fermion final state, gg(VV)e+eμ+μ/e+eνlνˉlgg (\rightarrow VV) \rightarrow e^+e^-\mu^+\mu^-/e^+e^-\nu_l\bar\nu_l. We investigate the interference contributions to invariant mass distributions of the four-fermion final state and other relevant kinematical observables. The relative importance of the different contributions is quantified for the process in the on-shell approximation, ggZZgg\rightarrow ZZ. We show that interferences of the heavy Higgs with the light Higgs boson and background contributions are essential for a correct description of the differential cross section. Even though they contribute below O(10%)\mathcal{O}(10\%) to those heavy Higgs signal cross sections, to which the experiments at the Large Hadron Collider were sensitive in its first run, we find that they are sizeable in certain regions of the parameter space that are relevant for future heavy Higgs boson searches. In fact, the interference contributions can significantly enhance the experimental sensitivity to the heavy Higgs boson.Comment: 24 pages, 13 figures; minor clarifications, updated references, matches published versio

    ppAZhpp\to A\to Zh and the wrong-sign limit of the Two-Higgs-Doublet Model

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    We point out the importance of the decay channels AZhA\to Zh and HVVH\to VV in the wrong-sign limit of the Two-Higgs-Doublet Model (2HDM) of type II. They can be the dominant decay modes at moderate values of tanβ\tan\beta, even if the (pseudo)scalar mass is above the threshold where the decay into a pair of top quarks is kinematically open. Accordingly, large cross sections ppAZhpp\to A\to Zh and ppHVVpp\to H\to VV are obtained and currently probed by the LHC experiments, yielding conclusive statements about the remaining parameter space of the wrong-sign limit. In addition, mild excesses - as recently found in the ATLAS analysis bbˉAZhb\bar b \to A\to Zh - could be explained. The wrong-sign limit makes other important testable predictions for the light Higgs boson couplings.Comment: 19 pages, 6 figures, v2: journal versio

    Characterization and modification of cavitation pattern in shock wave lithotripsy

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    The temporal and spatial dynamics of cavitation bubble cloud growth and collapse in extracorporeal shock wave lithotripsy (ESWL) is studied experimentally. The first objective is obtaining reproducible cloud patterns experimentally and comparing them with FDTD-calculations. Second, we describe a method to modify the cavitation pattern by timing two consecutive pressure waves at variable delays. It is found that the spatial and temporal dynamics of the cavitation bubble can be varied in large ranges. The ability to control cavitation dynamics allows discussing strategies for improvement of medical and biological applications of shock waves such as cell membrane poration and stone fragmentation

    Higgs Strahlung at the Large Hadron Collider in the 2-Higgs-Doublet Model

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    We present a calculation of all relevant contributions to associated production of a Higgs boson with a weak gauge boson in the 2-Higgs-Doublet Model (2HDM) at the LHC, ppVϕpp \rightarrow V\phi, with ϕ{h,H0,A}\phi\in\{h,H^0,A\} and V{W,Z}V\in\{W,Z\}. While for the WϕW\phi mode, this mostly amounts to a simple rescaling of the Standard Model (SM) cross section, the ZϕZ\phi cross section depends on several 2HDM parameters. The ratio σWϕ/σZϕ\sigma^{W\phi}/\sigma^{Z\phi}, for which we present the currently most complete SM prediction, therefore appears to be a sensitive probe of possible New Physics effects. We study its numerical dependence on the top and bottom Yukawa couplings, including their sign. Furthermore, we consider the Wϕ/ZϕW\phi/Z\phi ratio in exemplary 2HDM scenarios and briefly address the effects in the boosted regime. Analogous studies for other 2HDM scenarios will become possible with an upcoming version of the program vh@nnlo which incorporates the 2HDM effects.Comment: 32 pages, 18 figures; v2: discussion of boosted regime added, typos corrected, references added, version published in JHE
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