Discovery potential of the SM Higgs with ATLAS

The discovery potential of the Standard Model Higgs boson with the ATLAS experiment at the Large Hadron Collider is reviewed for the HEP-MAD'09 conference. The Higgs decay channels bb, tautau, gammagamma, WW(*) and ZZ(*) are discussed. The statistical procedure used for the combination of the individual analyses to obtain the discovery potential and exclusion limits is also presented

Stau as the Lightest Supersymmetric Particle in R-Parity Violating SUSY Models: Discovery Potential with Early LHC Data

We investigate the discovery potential of the LHC experiments for R-parity violating supersymmetric models with a stau as the lightest supersymmetric particle (LSP) in the framework of minimal supergravity. We classify the final states according to their phenomenology for different R-parity violating decays of the LSP. We then develop event selection cuts for a specific benchmark scenario with promising signatures for the first beyond the Standard Model discoveries at the LHC. For the first time in this model, we perform a detailed signal over background analysis. We use fast detector simulations to estimate the discovery significance taking the most important Standard Model backgrounds into account. Assuming an integrated luminosity of 1 inverse femtobarn at a center-of-mass energy of 7 TeV, we perform scans in the parameter space around the benchmark scenario we consider. We then study the feasibility to estimate the mass of the stau-LSP. We briefly discuss difficulties, which arise in the identification of hadronic tau decays due to small tau momenta and large particle multiplicities in our scenarios.Comment: 26 pages, 18 figures, LaTeX; minor changes, final version published in PR

Fractal Conductance Fluctuations of Classical Origin

In mesoscopic systems conductance fluctuations are a sensitive probe of electron dynamics and chaotic phenomena. We show that the conductance of a purely classical chaotic system with either fully chaotic or mixed phase space generically exhibits fractal conductance fluctuations unrelated to quantum interference. This might explain the unexpected dependence of the fractal dimension of the conductance curves on the (quantum) phase breaking length observed in experiments on semiconductor quantum dots.Comment: 5 pages, 4 figures, to appear in PR

Thep-Intersection Subgroups in Quasi-Simple and Almost Simple Finite Groups

AbstractLetpbe a fixed prime andGa finite group. A proper subgroupX<Gis called ap-intersection subgroupifX∩Xgis ap-group for eachg∈G\X, butXis not ap-group. In this paper we classify thep-intersection subgroups in the quasi-simple and almost simple finite groups

On the generalized Davenport constant and the Noether number

Known results on the generalized Davenport constant related to zero-sum sequences over a finite abelian group are extended to the generalized Noether number related to the rings of polynomial invariants of an arbitrary finite group. An improved general upper bound is given on the degrees of polynomial invariants of a non-cyclic finite group which cut out the zero vector.Comment: 14 page

Edge currents in the absence of edges

We investigate a charged two-dimensional particle in a homogeneous magnetic field interacting with a periodic array of point obstacles. We show that while Landau levels remain to be infinitely degenerate eigenvalues, between them the system has bands of absolutely continuous spectrum and exhibits thus a transport along the array. We also compute the band functions and the corresponding probability current.Comment: Final version, to appear in Phys. Lett. A; 10 LaTeX pages with 3 eps figure

First Calorimetric Measurement of OI-line in the Electron Capture Spectrum of 163^{163}Ho

The isotope $^{163}$Ho undergoes an electron capture process with a recommended value for the energy available to the decay, $Q_{\rm EC}$, of about 2.5 keV. According to the present knowledge, this is the lowest $Q_{\rm EC}$ value for electron capture processes. Because of that, $^{163}$Ho is the best candidate to perform experiments to investigate the value of the electron neutrino mass based on the analysis of the calorimetrically measured spectrum. We present for the first time the calorimetric measurement of the atomic de-excitation of the $^{163}$Dy daughter atom upon the capture of an electron from the 5s shell in $^{163}$Ho, OI-line. The measured peak energy is 48 eV. This measurement was performed using low temperature metallic magnetic calorimeters with the $^{163}$Ho ion implanted in the absorber. We demonstrate that the calorimetric spectrum of $^{163}$Ho can be measured with high precision and that the parameters describing the spectrum can be learned from the analysis of the data. Finally, we discuss the implications of this result for the Electron Capture $^{163}$Ho experiment, ECHo, aiming to reach sub-eV sensitivity on the electron neutrino mass by a high precision and high statistics calorimetric measurement of the $^{163}$Ho spectrum.Comment: 5 pages, 3 figure

Discovery potential of the SM Higgs with ATLAS

The discovery potential of the Standard Model Higgs boson with the ATLAS experiment at the Large Hadron Collider is reviewed for the HEP-MAD'09 conference. The Higgs decay channels bb, tau-tau, gamma-gamma, WW(*) and ZZ(*) are discussed. The statistical procedure used for the combination of the individual analyses to obtain the discovery potential and exclusion limits is also presented

Barkhausen Noise Analysis by Surrounding Coil

The Barkhausen effect (or Barkhausen noise)[1], discovered in 1919, was initially identified as the revealing of irreversible and discontinuous changes of magnetisation induced by an external magnetic field[2]. The interest of Barkhausen noise as a non destructive testing technique of magnetic materials is due to the interaction between the magnetic microstructure (magnetic domains, Bloch wall motion dynamic), microstructural state and stress state of the material [3,4,5,6]