66,829 research outputs found

    Implications of Z-normalization in the matrix profile

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    Companies are increasingly measuring their products and services, resulting in a rising amount of available time series data, making techniques to extract usable information needed. One state-of-the-art technique for time series is the Matrix Profile, which has been used for various applications including motif/discord discovery, visualizations and semantic segmentation. Internally, the Matrix Profile utilizes the z-normalized Euclidean distance to compare the shape of subsequences between two series. However, when comparing subsequences that are relatively flat and contain noise, the resulting distance is high despite the visual similarity of these subsequences. This property violates some of the assumptions made by Matrix Profile based techniques, resulting in worse performance when series contain flat and noisy subsequences. By studying the properties of the z-normalized Euclidean distance, we derived a method to eliminate this effect requiring only an estimate of the standard deviation of the noise. In this paper we describe various practical properties of the z-normalized Euclidean distance and show how these can be used to correct the performance of Matrix Profile related techniques. We demonstrate our techniques using anomaly detection using a Yahoo! Webscope anomaly dataset, semantic segmentation on the PAMAP2 activity dataset and for data visualization on a UCI activity dataset, all containing real-world data, and obtain overall better results after applying our technique. Our technique is a straightforward extension of the distance calculation in the Matrix Profile and will benefit any derived technique dealing with time series containing flat and noisy subsequences

    Impact parameter dependent S-matrix for dipole-proton scattering from diffractive meson electroproduction

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    We extract the S-matrix element for dipole-proton scattering using the data on diffractive electroproduction of vector mesons at HERA. By considering the full t dependence of this process we are able to reliably unfold the profile of the S-matrix for impact parameter values b>0.3 fm. We show that the results depend only weakly on the choice of the form for the vector meson wave function. We relate this result to the discussion about possible saturation effects at HERA.Comment: 15 pages, 6 figure

    A description of the Galactic Center excess in the Minimal Supersymmetric Standard Model

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    Observations with the Fermi Large Area Telescope (LAT) indicate an excess in gamma rays originating from the center of our Galaxy. A possible explanation for this excess is the annihilation of Dark Matter particles. We have investigated the annihilation of neutralinos as Dark Matter candidates within the phenomenological Minimal Supersymmetric Standard Model (pMSSM). An iterative particle filter approach was used to search for solutions within the pMSSM. We found solutions that are consistent with astroparticle physics and collider experiments, and provide a fit to the energy spectrum of the excess. The neutralino is a Bino/Higgsino or Bino/Wino/Higgsino mixture with a mass in the range 849284-92~GeV or 879787-97~GeV annihilating into W bosons. A third solutions is found for a neutralino of mass 174187174-187~GeV annihilating into top quarks. The best solutions yield a Dark Matter relic density 0.06<Ωh2<0.130.06 < \Omega h^2 <0.13. These pMSSM solutions make clear forecasts for LHC, direct and indirect DM detection experiments. If the MSSM explanation of the excess seen by Fermi-LAT is correct, a DM signal might be discovered soon.Comment: Large extension of previous paper: 2 more solutions found in the MSSM (Bino-Higgsino, Bino-Wino-Higgsino into WW and Bino into ttbar), added description on extra fit uncertainties, added description on flavor observables, added discussion on dwarf limit

    Transversity distributions in the nucleon in the large-N_c limit

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    We compute the quark and antiquark transversity distributions in the nucleon at a low normalization point of 600 MeV in the large-NcN_c limit, where the nucleon can be described as a soliton of an effective chiral theory (chiral quark-soliton model). The flavor-nonsinglet distributions, δu(x)δd(x)\delta u(x) - \delta d(x) and δuˉ(x)δdˉ(x)\delta\bar u(x) - \delta\bar d(x), appear in leading order of the 1/Nc1/N_c-expansion, while the flavor-singlet distributions, δu(x)+δd(x)\delta u(x) + \delta d(x) and δuˉ(x)+δdˉ(x)\delta\bar u(x) + \delta\bar d(x), are non-zero only in next-to-leading order. The transversity quark and antiquark distributions are found to be significantly different from the longitudinally polarized distributions Δu(x)±Δd(x)\Delta u (x) \pm \Delta d (x) and Δuˉ(x)±Δdˉ(x)\Delta\bar u (x) \pm \Delta\bar d (x), respectively, in contrast to the prediction of the naive non-relativistic quark model. We show that this affects the predictions for the spin asymmetries in Drell-Yan pair production in transversely polarized pp and ppbar collisions.Comment: 45 pages, 16 figure

    Evidence of Odderon-exchange from scaling properties of elastic scattering at TeV energies

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    We study the scaling properties of the differential cross section of elastic proton-proton (pppp) and proton-antiproton (ppˉp\bar p) collisions at high energies. We introduce a new scaling function, that scales -- within the experimental errors -- all the ISR data on elastic pppp scattering from s=23.5\sqrt{s} = 23.5 to 62.562.5 GeV to the same universal curve. We explore the scaling properties of the differential cross-sections of the elastic pppp and ppˉp\bar p collisions in a limited TeV energy range. Rescaling the TOTEM pppp data from s=7\sqrt{s} = 7 TeV to 2.762.76 and 1.961.96 TeV, and comparing it to D0 ppˉp\bar p data at 1.961.96 TeV, our results provide an evidence for a tt-channel Odderon exchange at TeV energies, with a significance of at least 6.26σ\sigma. We complete this work with a model-dependent evaluation of the domain of validity of the new scaling and its violations. We find that the H(x)H(x) scaling is valid, model dependently, within 200200 GeV s \leq \sqrt{s} \leq 8 8 TeV, with a t-t range gradually narrowing with decreasing colliding energies.Comment: Accepted in EPJ C, with typos fixed, reorganized institutions updated, Appendix A, B, C, D, E added, 60 pages, 29 figures, 13 tables, Odderon significance: 6.26 sigma, conclusions unchange

    Bulk Fermions in Warped Models with a Soft Wall

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    We study bulk fermions in models with warped extra dimensions in the presence of a soft wall. Fermions can acquire a position dependent bulk Dirac mass that shields them from the deep infrared, allowing for a systematic expansion in which electroweak symmetry breaking effects are treated perturbatively. Using this expansion, we analyze properties of bulk fermions in the soft wall background. These properties include the realization of non-trivial boundary conditions that simulate the ones commonly used in hard wall models, the analysis of the flavor structure of the model and the implications of a heavy top. We implement a soft wall model of electroweak symmetry breaking with custodial symmetry and fermions propagating in the bulk. We find a lower bound on the masses of the first bosonic resonances, after including the effects of the top sector on electroweak precision observables for the first time, of m_{KK} \gtrsim 1-3 TeV at the 95% C.L., depending on the details of the Higgs, and discuss the implications of our results for LHC phenomenology.Comment: 34 pages, 8 figure

    Exact probability function for bulk density and current in the asymmetric exclusion process

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    We examine the asymmetric simple exclusion process with open boundaries, a paradigm of driven diffusive systems, having a nonequilibrium steady state transition. We provide a full derivation and expanded discussion and digression on results previously reported briefly in M. Depken and R. Stinchcombe, Phys. Rev. Lett. {\bf 93}, 040602, (2004). In particular we derive an exact form for the joint probability function for the bulk density and current, both for finite systems, and also in the thermodynamic limit. The resulting distribution is non-Gaussian, and while the fluctuations in the current are continuous at the continuous phase transitions, the density fluctuations are discontinuous. The derivations are done by using the standard operator algebraic techniques, and by introducing a modified version of the original operator algebra. As a byproduct of these considerations we also arrive at a novel and very simple way of calculating the normalization constant appearing in the standard treatment with the operator algebra. Like the partition function in equilibrium systems, this normalization constant is shown to completely characterize the fluctuations, albeit in a very different manner.Comment: 10 pages, 4 figure
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