Search for neutral MSSM Higgs bosons in the fully hadronic di-tau decay channel with the ATLAS detector

The search for additional heavy neutral Higgs bosons predicted in Minimal Supersymmetric Extensions of the Standard Model is presented, using the direct decay channel into two tau leptons which themselves decay hadronically. The study is based on proton-proton collisions recorded in 2011 at a center-of-mass energy of 7 TeV with the ATLAS detector at the Large Hadron Collider at CERN. With a sample size corresponding to an integrated luminosity of 4.5 fb−1, no significant excess above the expected Standard Model background prediction is observed and CLs exclusion limits at a 95% confidence level are evaluated for values of the CP-odd Higgs boson mass mA between 140 GeV to 800 GeV within the context of the mhmax and mhmod± benchmark scenarios. The results are combined with searches for neutral Higgs bosons performed using proton-proton collisions at a center-of-mass energy of 8 TeV recorded with the ATLAS detector in 2012, with a corresponding integrated luminosity of 19.5 fb−1. The combination allowed an improvement of the exclusion limit at the order of 1 to 3 units in tan β. Within the context of this study, the structure of additional interactions during a single proton-proton collision (the “underlying event”) in di-jet final states is analyzed using collision data at a center-of-mass energy of 7 TeV recorded with the ATLAS detector in 2010, with a corresponding integrated luminosity of 37 pb−1. The contribution of the underlying event is measured up to an energy scale of 800 GeV and compared to the predictions of various models. For several models, significant deviations compared to the measurements are found and the results are provided for the optimization of simulation algorithms

Theoretical and Experimental Investigations Concerning Microgels of Varied Spherical Geometries

Polymer gels have been studied extensively due to their ability to simulate biological tissues and to swell or collapse reversibly in response to external stimuli. This work presents a variety of studies using poly-N-isopropylacrylamide (PNIPA) hydrogels. The projects have been carried out both in the lab of Dr. Zhibing Hu and in collaboration with others outside of UNT: (1) an analysis of the swelling kinetics of microgel spherical shells prepared using a novel design of microfluidic devices; (2) a comparison of the drug-release rates between nanoparticle structures having either core or core-with-shell (core-shell) designs; (3) an investigation into the thermodynamics of swelling for microgels of exceedingly small size

Zeta potential-viscosity relationship in kaolinite slurry in the presence of dispersants

AKÜ-BAPK / 042.MUH.03Kaolinite is a widely used additive for industrial applications. Hence, the properties of kaolinite affect the quality of the final materials. The fact that kaolinite is a heterogeneous mineral with dual charges has to be taken into account. In this study, the zeta potentials and the apparent viscosities of kaolinite suspensions in water in the presence of three dispersants; sodium silicate, sodium tripolyphosphate and sodium-polyacrylate at pH values of 4, 7 and 10 were determined. Diagrams of zeta potentials (ZPs) and viscosity as a function of dispersant concentration all show minima. The concentrations at which minima of these two properties appear do not coincide, except for those mineral dispersants at high pH values. The results are explained in terms of the spatial distribution of charges on basal and edge surfaces of kaolinite plates in acidic, neutral, and basic media.AKÜ-BAPK / 042.MUH.0

Remote Ruminal Temperature Monitoring in Feedlot Cattle: Effects of Bovine Respiratory Disease, Ruminal Acidosis, and Inclusion of Dietary ?-adrenergic Agonists

Ruminal temperature monitoring has potential as a useful tool to detect physiological changes in cattle resulting from illness and dietary changes. Heifer calves (n = 366, mean initial BW = 243 &plusmn; 30 kg) were assigned to one of three experimental management methods: Pulled based on visual signs of bovine respiratory disease (BRD, CON), administered metaphylaxis on d 0 and subsequently pulled based on visual signs of BRD (MET), or pulled based on visual signs of BRD or elevated ruminal temperature (TEMP). Overall ADG generally decreased as number of times identified with BRD increased; however, overall ADG of TEMP heifers did not differ (P &ge; 0.60) among those identified with BRD zero, one, or two times. Heifers identified with BRD twice began the finishing phase weighing 16.9 kg less (P < 0.01) than all others. Final BW of CON heifers identified with BRD twice was 37.5 kg less (P < 0.01) than CON heifers never identified, while number of times identified with BRD did not affect (P &ge; 0.13) final BW of TEMP and MET heifers. Carcasses from CON heifers identified with BRD twice were valued at 92 less (P &le; 0.02) than those from other CON heifers, while carcass value of TEMP and MET heifers was not affected (P &ge; 0.27) by number of times identified with BRD. To determine if temperature monitoring can detect ruminal acidosis, twelve ruminally cannulated steers (518 &plusmn; 28 kg) were assigned to one of three acidosis challenge treatments: no dietary change (CON), half of daily DMI replaced with cracked corn (HALF), or all of daily DMI replaced with cracked corn (CORN). Ruminal pH was negatively correlated (P &le; 0.02) with ruminal pH in HALF and CON steers on d 1 and 3, respectively. The amount of time above ruminal temperature of 39.0 or 39.45&deg;C was correlated (P &le; 0.05) with time spent below a ruminal pH of 5.5 in CORN steers. To determine if body temperature is affected by dietary inclusion of ZH, 67 steers, 73 fall-finished heifers, and 163 spring-finished heifers were assigned to control or ZH (7.3 mg/kg ZH) diets. Experimental periods included prior to (1) and during (2) ZH inclusion, and the withdrawal period (3). Temperatures of control steers increased by 0.10&deg;C from period 1 to period 3, while temperatures of ZH steers remained steady between periods 1 and 2, and increased by 0.15&deg;C during period 3. In fall-finished heifers, temperatures of control calves decreased by 0.17&deg;C from period 1 to period 2, and tended (P = 0.07) to decrease by 0.05&deg;C from period 2 to period 3. Temperatures of fall-finished heifers offered ZH decreased by 0.18&deg;C from period 1 to period 2, but increased by 0.06&deg;C from period 2 to period 3. Temperatures of spring-finished heifers were not affected (P &ge; 0.15) by treatment. Results indicate that metaphylaxis and ruminal temperature monitoring may assist in identification of subclinical BRD, that temperature monitoring may have the ability to detect ruminal temperature changes that correspond with declining ruminal pH, and that ZH does not increase ruminal temperature.Department of Animal Scienc

Massively-parallel electrical-conductivity imaging of hydrocarbonsusing the Blue Gene/L supercomputer

Large-scale controlled source electromagnetic (CSEM)three-dimensional (3D) geophysical imaging is now receiving considerableattention for electrical conductivity mapping of potential offshore oiland gas reservoirs. To cope with the typically large computationalrequirements of the 3D CSEM imaging problem, our strategies exploitcomputational parallelism and optimized finite-difference meshing. Wereport on an imaging experiment, utilizing 32,768 tasks/processors on theIBM Watson Research Blue Gene/L (BG/L) supercomputer. Over a 24-hourperiod, we were able to image a large scale marine CSEM field data setthat previously required over four months of computing time ondistributed clusters utilizing 1024 tasks on an Infiniband fabric. Thetotal initial data misfit could be decreased by 67 percent within 72completed inversion iterations, indicating an electrically resistiveregion in the southern survey area below a depth of 1500 m below theseafloor. The major part of the residual misfit stems from transmitterparallel receiver components that have an offset from the transmittersail line (broadside configuration). Modeling confirms that improvedbroadside data fits can be achieved by considering anisotropic electricalconductivities. While delivering a satisfactory gross scale image for thedepths of interest, the experiment provides important evidence for thenecessity of discriminating between horizontal and verticalconductivities for maximally consistent 3D CSEM inversions

Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector

Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured

Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations

Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results