4,674 research outputs found

    Roughness of stylolites: a stress-induced instability with non local interactions

    Full text link
    We study the roughness of stylolite surfaces (i.e. natural pressure-dissolution surfaces in sedimentary rocks) from profiler measurements at laboratory scales. The roughness is shown to be nicely described by a self-affine scaling invariance. At large scales, the roughness exponent is ζ1≈0.5\zeta_1 \approx 0.5 and very different from that at small scales where ζ2≈1.1\zeta_2 \approx 1.1. A cross-over length scale at around λc=1\lambda_c =1mm is well characterized and interpreted as a possible fossil stress measurement if related to the Asaro-Tiller-Grinfeld stress-induced instability. Measurements are consistent with a Langevin equation that describes the growth of stylolite surfaces in a quenched disordered material with long range elastic correlations.Comment: 4 pages, 5 figure

    Higgs boson form factor effects in ttˉt\bar t production by W−W+W^-W^+ and ZZZZ fusion

    Full text link
    We study the fusion processes W−W+→ttˉW^-W^+\to t\bar t and ZZ→ttˉZZ\to t\bar t observable at a future e−e+e^-e^+ collider and we discuss their sensitivity to an HttHtt form factor which may be due to compositeness, in particular when the HH and the top quark have common constituents. We make an amplitude analysis and illustrate which helicity amplitudes and cross sections for specific final ttˉt\bar t polarizations are especially sensitive to this form factor.Comment: 24 pages, 37 figures, version including changes suggested by the Physical Review D publication tea

    Specific supersimple properties of e−e+→γHe^-e^+\to \gamma H at high energy

    Full text link
    We study the process e−e+→γHe^-e^+\to \gamma H, where HH represents HSMH_{SM}, h0h^0 or H0H^0, which occurs at the one loop level in the standard model (SM) or in the minimal supersymmetric standard model (MSSM). We establish supersimple (sim) high energy expressions for all helicity amplitudes of this process, and we identify their level of accuracy for describing the various polarized and unpolarized observables, and for distinguishing SM from MSSM or another beyond the standard model (BSM). We pay a special attention to transverse electron-positron polarizations and azimuthal dependencies induced by the imaginary parts of the amplitudes, which are relatively important in this process.Comment: 33 pages, 66 figures. Version to appear in Phys. Rev.

    A supersimple analysis of e−e+→ttˉe^-e^+\to t \bar t at high energy

    Full text link
    According to supersimplicity in MSSM, a renormalization scheme (SRS) may be defined for any high energy 2-to-2 process, to the 1loop EW order; where the helicity conserving (HC) amplitudes, are expressed as a linear combination of just three universal logarithm-involving forms. All other helicity amplitudes vanish asymptotically. Including to these SRS amplitudes the corresponding counter terms, the "supersimple" expressions for the high energy HC amplitudes, renormalized on-shell, are obtained. Previously, this property was noted for a large number of processes that do not involve Yukawa interactions or renormalization group corrections. Here we extend it to e−e+→ttˉe^-e^+\to t \bar t, which does involve large Yukawa and renormalization group contributions. We show that the resulting "supersimple" expressions may provide an accurate description, even at energies comparable to the SUSY scale. Such descriptions clearly identify the origin of the important SUSY effects, and they may be used for quickly constraining physics contributions, beyond MSSM.Comment: 26 pages, 15 figures. Paper appeared in Phys. Rev. D. The Journal where Reference 20 has appeared has been adde

    The Higgs boson structure functions as signposts of new physics

    Full text link
    We show that the Higgs boson structure functions observable in the inclusive process e−e+→H+"anything"e^-e^+ \to H + {\rm "anything"} may reveal the presence of anomalous contributions corresponding to several types of new physics partners, Higgs boson compositeness or invisible (dark) matter. This could be done without making a difficult or even an impossible experimental analysis of the contents of the "anything". We give illustrations showing how the shapes of the various structure functions containing such typical new contributions may differ from the standard prediction and allow their identification.Comment: 19 pages, 36 figures, version accepted in Phys. Rev.

    Remarkable virtual SUSY effects in W±W^{\pm} production at high energy hadron colliders

    Full text link
    We present a complete 1-loop study of the electroweak corrections to the process ug→dW+ug\to dW^+ in MSSM and SM. The occurrence of a number of remarkable properties in the behavior of the helicity amplitudes at high energies is stressed, and the crucial role of the virtual SUSY contributions in establishing them, is emphasized. The approach to asymptopia of these amplitudes is discussed, comparing the effects of the logarithmic and constant contributions to the mass suppressed ones, which are relevant at lower energies. Applying crossing to ug→dW+ug\to d W^+, we obtain all subprocesses needed for the 1-loop electroweak corrections to W±W^\pm-production at LHC. The SUSY model dependence of such a production is then studied, and illustrations are given for the transverse W±W^{\pm} momentum distribution, as well as the angular distribution in the subprocess center of mass.Comment: 21 pages, 12 figures, version to appear in Phys.Rev.

    Test of the triple Higgs boson form factor in μ−μ+→HH\mu^-\mu^+\to HH

    Full text link
    We study the sensitivity of the process μ−μ+→HH\mu^-\mu^+\to HH to the q2q^2-dependence of the HHHHHH form factor, which can reflect the Higgs boson structure, especially in the case of compositeness. We compute the Born and 1 loop SM contribution to this process. We then show how the μ−μ+→HH\mu^-\mu^+\to HH polarized and unpolarized cross sections are modified by the presence of various types of anomalous contributions to the HHHHHH form factor, in particular Higgs constituents in the case of compositeness.Comment: 24 pages, 22 figures, Version to appear to Physical Review D. arXiv admin note: substantial text overlap with arXiv:1510.0410

    Signals for Neutralino Box Effects at LEP2

    Full text link
    We have computed the contribution to the observables of the final two fermion channel at LEP2, at the limiting energy q2=200GeV\sqrt{q^2}=200 GeV, coming from boxes with two neutralinos of purely gaugino type, of mass M=100GeVM=100 GeV. We find a potentially visible effect only for the muon channel, in the cross section and, to a lesser extent, in the forward-backward asymmetry. Analogous effects coming from the chargino box are also briefly discussed.Comment: 10 pages and 2 figures. e-mail: [email protected]
    • …
    corecore