Search for the Standard Model Higgs boson produced in association with top quarks and decaying into bb in pp collisions at √s =8TeV with the ATLAS detector

A search for the Standard Model Higgs boson produced in association with a top-quark pair, tt ¯ H , is presented. The analysis uses 20.3 fb−1 of pp collision data at s √ =8TeV , collected with the ATLAS detector at the Large Hadron Collider during 2012. The search is designed for the H→bb ¯ decay mode and uses events containing one or two electrons or muons. In order to improve the sensitivity of the search, events are categorised according to their jet and b-tagged jet multiplicities. A neural network is used to discriminate between signal and background events, the latter being dominated by tt ¯ +jets production. In the single-lepton channel, variables calculated using a matrix element method are included as inputs to the neural network to improve discrimination of the irreducible tt ¯ +bb ¯ background. No significant excess of events above the background expectation is found and an observed (expected) limit of 3.4 (2.2) times the Standard Model cross section is obtained at 95 % confidence level. The ratio of the measured tt ¯ H signal cross section to the Standard Model expectation is found to be μ=1.5±1.1 assuming a Higgs boson mass of 125GeV

Search for the b¯b decay of the Standard Model Higgs boson in associated (W/Z)H production with the ATLAS detector

A search for the bb¯ decay of the Standard Model Higgs boson is performed with the ATLAS experiment using the full dataset recorded at the LHC in Run 1. The integrated luminosities used are 4.7 and 20.3 fb−1 from pp collisions at s√=7 and 8 TeV, respectively. The processes considered are associated (W/Z)H production, where W → eν/μν, Z → ee/μμ and Z → νν. The observed (expected) deviation from the background-only hypothesis corresponds to a significance of 1.4 (2.6) standard deviations and the ratio of the measured signal yield to the Standard Model expectation is found to be μ = 0.52 ± 0.32 (stat.) ± 0.24 (syst.) for a Higgs boson mass of 125.36 GeV. The analysis procedure is validated by a measurement of the yield of (W/Z)Z production with Z→bb¯ in the same final states as for the Higgs boson search, from which the ratio of the observed signal yield to the Standard Model expectation is found to be 0.74 ± 0.09 (stat.) ± 0.14 (syst.)

Investing in Creativity: A Study of the Support Structure for U.S. Artists

Documents and analyzes the environment of support for individual artists. Provides a framework for analysis of various dimensions of the support structure, nationally and in specific sites across the U.S. Includes support programs and policy initiatives

The relationship of school size and the socio-economic status, ethnic origin, gender, and employment status of students on extent of participation involvement in student activities in selected North Carolina high schools

The purpose of this study was to determine participation patterns in student activities in selected North Carolina public high schools and to examine factors influencing participation and leadership. Both quantitative and qualitative methods were used to collect data for the study. The quantitative methods included a Student Activity Survey Inventory administered to 372 students from the eight selected high schools. Principals and activity sponsors at these high schools were interviewed using a structured questionnaire. The qualitative methodology involved a historical review including school records, the principals' monthly reports, school yearbooks, Southern Association accreditation reports, and the North Carolina Public Schools Annual Report

Phenomenology of Mirror Fermions in the Littlest Higgs Model with T-Parity

Little Higgs models are an interesting alternative to explain electroweak symmetry breaking without fine-tuning. Supplemented with a discrete symmetry (T-parity) constraints from electroweak precision data are naturally evaded and also a viable dark matter candidate is obtained. T-parity implies the existence of new (mirror) fermions in addition to the heavy gauge bosons of the little Higgs models. In this paper we consider the effects of the mirror fermions on the phenomenology of the littlest Higgs model with T-parity at the LHC. We study the most promising production channels and decay chains for the new particles. We find that the mirror fermions have a large impact on the magnitude of signal rates and on the new physics signatures. Realistic background estimates are given.Comment: 13 p

Secure Similar Sequence Query on Outsourced Genomic Data

The growing availability of genomic data is unlocking research potentials on genomic-data analysis. It is of great importance to outsource the genomic-analysis tasks onto clouds to leverage their powerful computational resources over the large-scale genomic sequences. However, the remote placement of the data raises personal-privacy concerns, and it is challenging to evaluate data-analysis functions on outsourced genomic data securely and efficiently. In this work, we study the secure similar-sequence-query (SSQ) problem over outsourced genomic data, which has not been fully investigated. To address the challenges of security and efficiency, we propose two protocols in the mixed form, which combine two-party secure secret sharing, garbled circuit, and partial homomorphic encryptions together and use them to jointly fulfill the secure SSQ function. In addition, our protocols support multi-user queries over a joint genomic data set collected from multiple data owners, making our solution scalable. We formally prove the security of protocols under the semi-honest adversary model, and theoretically analyze the performance. We use extensive experiments over real-world dataset on a commercial cloud platform to validate the efficacy of our proposed solution, and demonstrate the performance improvements compared with state-of-the-art works

Serendipitous discoveries in microarray analysis

Background Scientists are capable of performing very large scale gene expression experiments with current microarray technologies. In order to find significance in the expression data, it is common to use clustering algorithms to group genes with similar expression patterns. Clusters will often contain related genes, such as co-regulated genes or genes in the same biological pathway. It is too expensive and time consuming to test all of the relationships found in large scale microarray experiments. There are many bioinformatics tools that can be used to infer the significance of microarray experiments and cluster analysis. Materials and methods In this project we review several existing tools and used a combination of them to narrow down the number of significant clusters from a microarray experiment. Microarray data was obtained through the Cerebellar Gene Regulation in Time and Space (Cb GRiTS) database [2]. The data was clustered using paraclique, a graph-based clustering algorithm. Each cluster was evaluated using Gene-Set Cohesion Analysis Tool (GCAT) [3], ONTO-Pathway Analysis [4], and Allen Brain Atlas data [1]. The clusters with the lowest p-values in each of the three analysis methods were researched to determine good candidate clusters for further experimental confirmation of gene relationships. Results and conclusion While looking for genes important to cerebellar development, we serendipitously came across interesting clusters related to neural diseases. For example, we found two clusters that contain genes known to be associated with Parkinson’s disease, Huntington’s disease, and Alzheimer’s disease pathways. Both clusters scored low in all three analyses and have very similar expression patterns but at different expression levels. Such unexpected discoveries help unlock the real power of high throughput data analysis

Search for flavour-changing neutral-current interactions of a top quark and a gluon in pp collisions at √s = 13 TeV with the ATLAS detector

A search is presented for the production of a single top quark via left-handed flavour-changing neutralcurrent (FCNC) interactions of a top quark, a gluon and an up or charm quark. Two production processes are considered: u + g → t and c + g → t. The analysis is based on proton–proton collision data taken at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. The data set corresponds to an integrated luminosity of 139 fb−1. Events with exactly one electron or muon, exactly one b-tagged jet and missing transverse momentum are selected, resembling the decay products of a singly produced top quark. Neural networks based on kinematic variables differentiate between events from the two signal processes and events from background processes. The measured data are consistent with the background-only hypothesis, and limits are set on the production cross-sections of the signal processes: σ (u + g → t) × B(t → W b) × B(W → ν) < 3.0 pb and σ (c + g → t)×B(t → W b)×B(W → ν) < 4.7 pb at the 95% confidence level, with B(W → ν) = 0.325 being the sum of branching ratios of all three leptonic decay modes of the W boson. Based on the framework of an effective field theory, the cross-section limits are translated into limits on the strengths of the tug and tcg couplings occurring in the theory: |C ut uG|/ 2 < 0.057 TeV−2 and |C ct uG|/ 2 < 0.14 TeV−2. These bounds correspond to limits on the branching ratios of FCNC-induced top-quark decays: B(t → u + g) < 0.61 × 10−4 and B(t → c + g) < 3.7 × 10−

Threshold resummation for high-transverse-momentum Higgs production at the LHC

We study the resummation of large logarithmic QCD corrections for the process pp ->H+ X when the Higgs boson H is produced at high transverse momentum. The corrections arise near the threshold for partonic reaction and originate from soft gluon emission. We perform the all-order resummation at next-to-leading logarithmic accuracy and match the resummed result with the next-to-leading order perturbative predictions. The effect of resummation on the Higgs transverse momentum distribution at the LHC is discussed.Comment: 19 pages, 3 figure

Dark Matter Searches: The Nightmare Scenario

The unfortunate case where the Large Hadron Collider (LHC) fails to discover physics Beyond the Standard Model (BSM) is sometimes referred to as the "Nightmare scenario" of particle physics. We study the consequences of this hypothetical scenario for Dark Matter (DM), in the framework of the constrained Minimal Supersymmetric Standard Model (cMSSM). We evaluate the surviving regions of the cMSSM parameter space after null searches at the LHC, using several different LHC configurations, and study the consequences for DM searches with ton-scale direct detectors and the IceCube neutrino telescope. We demonstrate that ton-scale direct detection experiments will be able to conclusively probe the cMSSM parameter space that would survive null searches at the LHC with 100fb$^{-1}$ of integrated luminosity at 14TeV. We also demonstrate that IceCube (80 strings plus DeepCore) will be able to probe as much as 17% of the currently favoured parameter space after 5 years of observation.Comment: V2: 24 pages, 6 figures, 4 tables. Replaced to match version published in JCAP. Minor revisions made to address referee's comment