Parallel computing, benchmarking and ATLAS software on ARM

Includes bibliographical references,This thesis explores the use of the ARM architecture in high energy physics computing. ARM processors are predominantly found in smartphones and mobile tablets. Results from benchmarks which were performed on the armv7l architecture are presented. These provide qualitative data as well as confirmation that specialized high energy physics software does run on ARM. This thesis presents the first ever port of the ATLAS software stack to the ARM architecture, as well as the issues that ensued. A new framework, ANA, is introduced which facilitates the compilation of the ATLAS software stack on ARM

Fiducial cross-section measurements of top-quark pair production in association with a photon at s\sqrt{s} = 13 TeV with the ATLAS detector

Top-quark pairs in association with final state particles are produced in large quantities at the LHC due to the high centre-of-mass energy available in proton-proton collisions. One such topology is that of a prompt photon radiated from the top quark in addition to the final state particles from the top quark decay. Using 36.1 fb$^{-1}$ of data collected at $\sqrt{s}$ = 13 TeV with the ATLAS detector, fiducial cross-section results are shown in the single-lepton and dilepton channels. Object-level and event-level neural networks are used to increase sensitivity.Comment: International Workshop on Top Quark Physics, Bad Neuenahr, Germany, September 16-21, 201

Fiducial cross-section measurements of the production of a prompt photon in association with a top-quark pair at s=13\sqrt{s}=13 TeV with the ATLAS detector at the LHC

The cross sections for top-quark pair production in association with a photon are measured in a fiducial volume with the ATLAS detector at a centre-of-mass energy of 13 TeV. Results are presented using proton-proton collision data collected by the LHC during 2015 and 2016, amounting to a total of 36.1 fb$^{-1}$. This also presents the first $t\bar{t}\gamma$ cross-section measurements performed in the dilepton channels. Exactly one photon is required to have $p_{\text{T}} > 20$ GeV and be isolated based on track and calorimeter information. At least two (four) jets are required in the dilepton (single-lepton) channels, with at least one jet originating from a $b$-quark. Two separate neural network algorithms are used to help reduce the impact backgrounds play in the final measurements. The Prompt Photon Tagger is trained on information from energy deposits in the calorimeters to distinguish prompt photons from hadronic fake photons. The output of this neural network is fed into the Event-level Discriminator that uses event information to classify signal from the sum of all backgrounds. A maximum likelihood fit is performed on the output of the Event-level Discriminator to determine the fiducial cross section of the signal process. The fiducial cross section for the single-lepton and dilepton channel are measured to be $521 \pm 9 \text{(stat.)} \pm 41 \text{(sys.)}$ fb and $69 \pm 3 \text{(stat.)} \pm 4\text{(sys.)}$ fb, respectively. In total, eight cross-section measurements are performed and all agree with theoretical next-to-leading-order predictions.Comment: PhD dissertatio

Identification of Morpholino Thiophenes as Novel Mycobacterium tuberculosis Inhibitors, Targeting QcrB

With the emergence of multidrug-resistant strains of <i>Mycobacterium tuberculosis</i> there is a pressing need for new oral drugs with novel mechanisms of action. Herein, we describe the identification of a novel morpholino–thiophenes (MOT) series following phenotypic screening of the Eli Lilly corporate library against <i>M. tuberculosis</i> strain H37Rv. The design, synthesis, and structure–activity relationships of a range of analogues around the confirmed actives are described. Optimized leads with potent whole cell activity against H37Rv, no cytotoxicity flags, and in vivo efficacy in an acute murine model of infection are described. Mode-of-action studies suggest that the novel scaffold targets QcrB, a subunit of the menaquinol cytochrome <i>c</i> oxidoreductase, part of the bc1-aa3-type cytochrome <i>c</i> oxidase complex that is responsible for driving oxygen-dependent respiration

Circumstellar Medium Interaction in SN 2018lab, A Low-Luminosity II-P Supernova observed with TESS

We present photometric and spectroscopic data of SN 2018lab, a low luminosity type IIP supernova (LLSN) with a V-band peak luminosity of $-15.1\pm0.1$ mag. SN 2018lab was discovered by the Distance Less Than 40 Mpc (DLT40) SNe survey only 0.73 days post-explosion, as determined by observations from the Transiting Exoplanet Survey Satellite (TESS). TESS observations of SN 2018lab yield a densely sampled, fast-rising, early time light curve likely powered by circumstellar medium (CSM) interaction. The blue-shifted, broadened flash feature in the earliest spectra ($<$2 days) of SN 2018lab provide further evidence for ejecta-CSM interaction. The early emission features in the spectra of SN 2018lab are well described by models of a red supergiant progenitor with an extended envelope and close-in CSM. As one of the few LLSNe with observed flash features, SN 2018lab highlights the need for more early spectra to explain the diversity of flash feature morphology in type II SNe

The Carnegie Supernova Project: First Near-Infrared Hubble Diagram to z~0.7

The Carnegie Supernova Project (CSP) is designed to measure the luminosity distance for Type Ia supernovae (SNe Ia) as a function of redshift, and to set observational constraints on the dark energy contribution to the total energy content of the Universe. The CSP differs from other projects to date in its goal of providing an I-band {rest-frame} Hubble diagram. Here we present the first results from near-infrared (NIR) observations obtained using the Magellan Baade telescope for SNe Ia with 0.1 < z < 0.7. We combine these results with those from the low-redshift CSP at z <0.1 (Folatelli et al. 2009). We present light curves and an I-band Hubble diagram for this first sample of 35 SNe Ia and we compare these data to 21 new SNe Ia at low redshift. These data support the conclusion that the expansion of the Universe is accelerating. When combined with independent results from baryon acoustic oscillations (Eisenstein et al. 2005), these data yield Omega_m = 0.27 +/- 0.0 (statistical), and Omega_DE = 0.76 +/- 0.13 (statistical) +/- 0.09 (systematic), for the matter and dark energy densities, respectively. If we parameterize the data in terms of an equation of state, w, assume a flat geometry, and combine with baryon acoustic oscillations, we find that w = -1.05 +/- 0.13 (statistical) +/- 0.09 (systematic). The largest source of systematic uncertainty on w arises from uncertainties in the photometric calibration, signaling the importance of securing more accurate photometric calibrations for future supernova cosmology programs. Finally, we conclude that either the dust affecting the luminosities of SNe Ia has a different extinction law (R_V = 1.8) than that in the Milky Way (where R_V = 3.1), or that there is an additional intrinsic color term with luminosity for SNe Ia independent of the decline rate.Comment: 44 pages, 23 figures, 9 tables; Accepted for publication in the Astrophysical Journa

Supernova 2018cuf : a type iip supernova with a slow fall from plateau

We present multiband photometry and spectroscopy of SN 2018cuf, a Type IIP ("P"for plateau) supernova (SN) discovered by the Distance Less Than 40 Mpc Survey within 24 hr of explosion. SN 2018cuf appears to be a typical SN IIP, with an absolute V-band magnitude of -16.73 ± 0.32 at maximum and a decline rate of 0.21 ± 0.05 mag/50 days during the plateau phase. The distance of the object was constrained to be 41.8 ± 5.7 Mpc by using the expanding photosphere method. We used spectroscopic and photometric observations from the first year after the explosion to constrain the progenitor of SN 2018cuf using both hydrodynamic light-curve modeling and late-time spectroscopic modeling. The progenitor of SN 2018cuf was most likely a red supergiant of about 14.5 Me that produced 0.04 ± 0.01 Me 56Ni during the explosion. We also found ∼0.07 Me of circumstellar material (CSM) around the progenitor is needed to fit the early light curves, where the CSM may originate from presupernova outbursts. During the plateau phase, high-velocity features at ∼11,000 km s-1 were detected in both the optical and near-infrared spectra, supporting the possibility that the ejecta were interacting with some CSM. A very shallow slope during the postplateau phase was also observed, and it is likely due to a low degree of nickel mixing or the relatively high nickel mass in the SN.Fil: Dong, Yize. University of California at Davis; Estados UnidosFil: Valenti, S.. University of California at Davis; Estados UnidosFil: Bostroem, K. A.. University of California at Davis; Estados UnidosFil: Sand, D. J.. University of Arizona; Estados UnidosFil: Andrews, Jennifer E.. University of Arizona; Estados UnidosFil: Galbany, Lluís. Universidad de Granada; EspañaFil: Jha, Saurabh W.. State University of New Jersey; Estados UnidosFil: Eweis, Youssef. State University of New Jersey; Estados UnidosFil: Kwok, Lindsey. State University of New Jersey; Estados UnidosFil: Hsiao, Eric. Florida State University; Estados UnidosFil: Davis, Scott. Florida State University; Estados UnidosFil: Brown, Peter J.. Texas A&M University; Estados UnidosFil: Kuncarayakti, H.. University of Turku; FinlandiaFil: Maeda, Keiichi. Kyoto University; JapónFil: Rho, Jeonghee. SETI Institute; Estados UnidosFil: Amaro, R. C.. University of Arizona; Estados UnidosFil: Anderson, J. P.. European Southern Observatory Chile; ChileFil: Arcavi, Iair. Universitat Tel Aviv; IsraelFil: Burke, Jamison. University of California; Estados UnidosFil: Dastidar, Raya. Aryabhatta Research Institute of observational sciences; IndiaFil: Folatelli, Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Haislip, Joshua. University of North Carolina at Chapel Hill; Estados UnidosFil: Hiramatsu, Daichi. University of California; Estados UnidosFil: Hosseinzadeh, Griffin. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Howell, D. Andrew. University of California; Estados UnidosFil: Jencson, J.. University of Arizona; Estados UnidosFil: Kouprianov, Vladimir. University of North Carolina at Chapel Hill; Estados UnidosFil: Lundquist, M.. University of Arizona; Estados UnidosFil: Lyman, J. D.. University of Warwick; Reino UnidoFil: McCully, Curtis. University of California; Estados Unido

The origin and evolution of the normal Type Ia SN 2018aoz with infant-phase reddening and excess emission

SN~2018aoz is a Type Ia SN with a $B$-band plateau and excess emission in the infant-phase light curves $\lesssim$ 1 day after first light, evidencing an over-density of surface iron-peak elements as shown in our previous study. Here, we advance the constraints on the nature and origin of SN~2018aoz based on its evolution until the nebular phase. Near-peak spectroscopic features show the SN is intermediate between two subtypes of normal Type Ia: Core-Normal and Broad-Line. The excess emission could have contributions from the radioactive decay of surface iron-peak elements as well as ejecta interaction with either the binary companion or a small torus of circumstellar material. Nebular-phase limits on H$\alpha$ and He~I favour a white dwarf companion, consistent with the small companion size constrained by the low early SN luminosity, while the absence of [O~I] and He~I disfavours a violent merger of the progenitor. Of the two main explosion mechanisms proposed to explain the distribution of surface iron-peak elements in SN~2018aoz, the asymmetric Chandrasekhar-mass explosion is less consistent with the progenitor constraints and the observed blueshifts of nebular-phase [Fe~II] and [Ni~II]. The helium-shell double-detonation explosion is compatible with the observed lack of C spectral features, but current 1-D models are incompatible with the infant-phase excess emission, $B_{\rm max}-V_{\rm max}$ color, and absence of nebular-phase [Ca~II]. Although the explosion processes of SN~2018aoz still need to be more precisely understood, the same processes could produce a significant fraction of Type Ia SNe that appear normal after $\sim$ 1 day.Comment: Submitted for publication in ApJ. 35 pages, 16 figures, 7 table