A Leakage Current-based Measurement of the Radiation Damage in the ATLAS Pixel Detector

A measurement has been made of the radiation damage incurred by the ATLAS Pixel Detector barrel silicon modules from the beginning of operations through the end of 2012. This translates to hadronic fluence received over the full period of operation at energies up to and including 8 TeV. The measurement is based on a per-module measurement of the silicon sensor leakage current. The results are presented as a function of integrated luminosity and compared to predictions by the Hamburg Model. This information can be used to predict limits on the lifetime of the Pixel Detector due to current, for various operating scenarios.Comment: 10 pages, 7 figures, talk presented on behalf of the ATLAS Collaboration at the 7th International Workshop on Semiconductor Pixel Detectors for Particles and Imaging (PIXEL2014), 1 - 5 Sep 2014, Niagara Falls, Ontario, Canada; to appear in the Conference Proceedings to be published by JINS

Heavy Flavor Physics at ATLAS and CMS

Recent results on heavy flavor physics using data from the ATLAS and CMS detectors are presented. The searches for new physics signatures in CP violation of B0_s - anti(B0_s) mixing and in B0_d --> K*0 mu+ mu- decays are discussed. The bottomonium and open-b production results obtained from proton-proton collisions at LHC are shown. The results are based on data samples containing mu+ mu- pairs collected with the ATLAS or CMS detectors by their corresponding muon trigger systems.Comment: 5 pages, 4 figures, talk given on behalf of the ATLAS and CMS Collaborations at the 7th joint International HADRON STRUCTURE '13 Conference, Slovaki

Pentaquark Searches at CDF

Experimental results of a search for the Xi_(3/2)(1860) cascade pentaquark state in data collected with the CDF 2 Detector in Run II at the Tevatron are presented. No evidence for these states in the neutral Xi-pi+ and doubly charged Xi-pi- modes has been found. Preliminary upper limits on yields at 1862 MeV/c**2 relative to the well established resonance Xi*0(1530) are presented.Comment: 5 pages, 6 figures, talk given at DIS 2004 Workshop, to be published in Proceedings of the DIS 2004 Worksho

Latest Results on Orbitally Excited Strange Bottom Mesons with the CDF II Detector

We present the latest results on the spectroscopy of orbitally excited strange bottom mesons from 1 fb^{-1} of CDF data. The measurements are performed with fully reconstructed B- decays collected by the CDF II detector at the sqrt(s)-energy of 1.96 TeV in both the di-muon and the fully hadronic trigger paths.Comment: 4 pages, 6 figures; talk given at ICHEP 2006, July 26 - August 2, 2006, Moscow, Russi

Heavy Flavor Production in CDF II Detector

For data collected with the CDF Run II detector, measurements of the charm and bottom production cross-sections are presented. The results are based both on large samples of fully reconstructed hadron decay products of charm and bottom made available by the tracking triggers and on a calorimeter jet triggered sample tagged by the presence of a secondary vertex. The experimental data are compared with theoretical predictions from recent next-to-leading order (NLO) QCD calculations.Comment: 5 pages, 3 figures; a write up of the talk given on behalf of the CDF Collaboration at the XVII Particles and Nuclei International Conference, PANIC 05, October 24-28, 2005, Santa Fe, New Mexico, U.S.

Multiplet effects in orbital and spin ordering phenomena: A hybridization-expansion quantum impurity solver study

Orbital and spin ordering phenomena in strongly correlated systems are commonly studied using the local-density approximation + dynamical mean-field theory approach. Typically, however, such simulations are restricted to simplified models (density-density Coulomb interactions, high symmetry couplings and few-band models). In this work we implement an efficient general hybridization-expansion continuous-time quantum Monte Carlo impurity solver (Krylov approach) which allows us to investigate orbital and spin ordering in a more realistic setting, including interactions that are often neglected (e.g., spin-flip and pair-hopping terms), enlarged basis sets (full d versus eg), low-symmetry distortions, and reaching the very low-temperature (experimental) regime. We use this solver to study ordering phenomena in a selection of exemplary low-symmetry transition-metal oxides: LaMnO3 and rare-earth manganites as well as the perovskites CaVO3 and YTiO3. We show that spin-flip and pair hopping terms do not affect the Kugel-Khomskii orbital-order melting transition in rare-earth manganites, or the suppression of orbital fluctuations driven by crystal field and Coulomb repulsion. For the Mott insulator YTiO3 we find a ferromagnetic transition temperature 50 K, in remarkably good agreement with experiments. For LaMnO3 we show that the classical t2g-spin approximation, commonly adopted for studying manganites, yields indeed an occupied eg orbital in very good agreement with that obtained for the full d 5-orbital Hubbard model, while the spin-spin e_g-t_{2g} correlation function calculated from the full d model is 0.74, very close to the value expected for aligned eg and t2g spins; the eg spectral function matrix is also well reproduced. Finally, we show that the t2g screening reduces the eg-eg Coulomb repulsion by about 10%Comment: 9 pages, 5 figure

ATLAS Pixel Radiation Monitoring with HVPP4 System

In this talk we present the basis for the protocol for radiation monitoring of the ATLAS Pixel Sensors. The monitoring is based on a current measurement system, HVPP4. The status on the ATLAS HVPP4 system development is also presented.Comment: Talk given at DPF-2009, Detroit, MI, July 2009; 8 pages, 4 figures, 6 tables; To be published in the proceedings of DPF-2009, Detroit, MI, July 2009, eConf C09072

Computation of current-voltage characteristics of weak links

Simplified model for current-voltage characteristics of weak links is suggested. It is based on approach which considers Andreev reflections as responsible for the dissipative current through the metallic Josephson junction. The model allows to calculate current-voltage characteristics of weak links (superconductor - normal metal - superconductor junctions, microbridges, superconducting nanowires) for different thicknesses of the normal layer at different temperatures. The current-voltage characteristics of tin microbridges at different temperatures were computed.Comment: 11 pages, 5 figure