Physical Sciences and Mathematics Commons^™

Measurement Of B (Bs →Dsx) With Bs Semileptonic Tagging, B. Wang, K. Kinoshita, H. Aihara, D. M. Asner, T. Aushev, R. Ayad, V. Babu, I. Badhrees, A. M. Bakich, P. Behera, C. Beleño, J. Bennett, M. Bessner, V. Bhardwaj, T. Bilka, J. Biswal, A. Bobrov, G. Bonvicini, A. Bozek

Faculty and Student Publications

We report the first direct measurement of the inclusive branching fraction B(Bs→DsX) via Bs tagging in e+e-→ (5S) events. Tagging is accomplished through a partial reconstruction of semileptonic decays Bs→DsXℓν, where X denotes unreconstructed additional hadrons or photons and ℓ is an electron or muon. With 121.4 fb-1 of data collected at the (5S) resonance by the Belle detector at the KEKB asymmetric-energy e+e- collider, we obtain B(Bs→DsX)=(60.2±5.8±2.3)%, where the first uncertainty is statistical and the second is systematic.

Search For The Decay Bs0 →Ηη, B. Bhuyan, K. J. Nath, J. Borah, I. Adachi, H. Aihara, S. Al Said, D. M. Asner, H. Atmacan, V. Aulchenko, T. Aushev, R. Ayad, V. Babu, I. Badhrees, A. M. Bakich, P. Behera, J. Bennett, V. Bhardwaj, T. Bilka, J. Biswal

Faculty and Student Publications

We report results from a search for the decay Bs0→ηη using 121.4 fb-1 of data collected at the (5S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We do not observe any signal and set an upper limit on the branching fraction of 14.3×10-5 at 90% confidence level. This result represents a significant improvement over the previous most stringent limit.

Surface Morphologies In A Mars-Analog Ca-Sulfate Salar, High Andes, Northern Chile, Nancy W. Hinman, Michael H. Hofmann, Kimberly Warren-Rhodes, Michael S. Phillips, Nora Noffke, Nathalie A. Cabrol, Guillermo Chong Diaz, Cecilia Demergasso, Cinthya Tebes-Cayo, Oscar Cabestro, Janice L. Bishop, Virginia C. Gulick, David Summers, Pablo Sobron, Michael Mcinenly, Jeffrey Moersch, Constanza Rodriguez, Philippe Sarazzin, Kevin L. Rhodes, Camila Javiera Riffo Contreras, David Wettergreen, Victor Parro

OES Faculty Publications

Salar de Pajonales, a Ca-sulfate salt flat in the Chilean High Andes, showcases the type of polyextreme environment recognized as one of the best terrestrial analogs for early Mars because of its aridity, high solar irradiance, salinity, and oxidation. The surface of the salar represents a natural climate-transition experiment where contemporary lagoons transition into infrequently inundated areas, salt crusts, and lastly dry exposed paleoterraces. These surface features represent different evolutionary stages in the transition from previously wetter climatic conditions to much drier conditions today. These same stages closely mirror the climate transition on Mars from a wetter early Noachian to …

Polarization Properties Of Millisecond Pulsars: Astrophysical Interpretations And Applications, Haley Megan Wahl

Graduate Theses, Dissertations, and Problem Reports

Pulsars are some of the most extreme objects in the universe; their small yet incredibly predictable spin periods coupled with their strong magnetic fields make them ideal laboratories for study. Not only are they interesting objects themselves, but they can also help us probe different astrophysical environments, such as the interstellar magnetic field and the solar corona.

These stars are highly polarized, and that polarization comes into play in various fields of pulsar physics (such as constraining models of pulsar emission), but obtaining that polarization information can be difficult, as the polarization properties of the light can change as the …

Deep Learning Detection In The Visible And Radio Spectrums, Greg Clancy Murray

Graduate Theses, Dissertations, and Problem Reports

Deep learning models with convolutional neural networks are being used to solve some of the most difficult problems in computing today. Complicating factors to the use and development of deep learning models include lack of availability of large volumes of data, lack of problem specific samples, and the lack variations in the specific samples available. The costs to collect this data and to compute the models for the task of detection remains a inhibitory condition for all but the most well funded organizations. This thesis seeks to approach deep learning from a cost reduction and hybrid perspective — incorporating techniques …

Inferential Statistics And Information Theoretical Measures: An Approach To Interference Detection In Radio Astronomy, Morgan R. Dameron

Graduate Theses, Dissertations, and Problem Reports

In a time when technology is rapidly growing, radio observatories are now able to expand their computational power to achieve higher receiver sensitivity power and a more flexible realtime computing approach to probe the universe for its composition and study new astronomical phenomena. This allows searches to go deeper into the universe, and results in the recording of massive quantities of observed data. At the same time, this increases the amount of radio frequency interference (RFI) found in the obtained observatory data. The high power of RFI easily masks the low power of extraterrestrial signals, making them hard to detect …

Studies Of Electromagnetic Counterparts To Gravitational-Wave Sources And The Nonlinear Gravitational-Wave Memory Effect, Ashok Choudhary

Graduate Theses, Dissertations, and Problem Reports

In this dissertation, theoretical/computational results are presented from the investigations of three different topics within the general research areas of gravitational wave astrophysics and electromagnetic counterparts. First, general relativistic force-free electromagnetic theory and its application to black hole magnetospheres are discussed. In this connection, simulations of a binary black hole merger are examined using the open-source software, GiRaFFE, which is used to model black holes’ magnetospheres and to study supermassive black-hole binary mergers in an external magnetic field. In the simulations, a helical magnetic field structure around each black hole is observed. Electromagnetic energy flux is observed during the inspiral …

Bayesian Methods For Multi-Messenger Analysis Of Supermassive Black Hole Binaries: Pulsars And Quasars And Gravitational Waves, Oh My!, Caitlin A. Witt

Graduate Theses, Dissertations, and Problem Reports

Supermassive black hole binaries (SMBHBs) can lurk, often unseen, in the centers of post-merger galaxies, and pulsar timing arrays (PTAs) are rapidly approaching the sensitivities required to detect nanohertz gravitational waves (GWs) from these giant pairs. Independently, numerous electromagnetic surveys are seeking evidence of these dynamic duos’ effects on their host galaxies by searching for periodicities in time-domain observations. Combining these two methods to use multi-messenger techniques allows us to learn more about these binaries than using one messenger alone. In this thesis, we have created Bayesian methods to search for SMBHBs using electromagnetic observations of quasars and through GW …

New Techniques In Celestial Mechanics, Ali Abdulrasool Abdulhussein

Graduate Theses, Dissertations, and Problem Reports

It is shown that for the classical system of the N body problem ( Newtonian Motion), if the motion of the N particles starts from a planar initial motion at t=t_{0}, then the motion of the N particles continues to be planar for every t\in[t_{0},t_{1}], assuming that no collisions occur between the N particles. Same argument is shown about the linear motion, namely, for the classical system of the N body problem, if the motion of the N particles starts from a linear initial motion at t=t_{0}, then the motion of the N particles continues to be linear for every …

Pathfinding Fast Radio Bursts Localizations Using Very Long Baseline Interferometry, Pranav Rohit Sanghavi

Graduate Theses, Dissertations, and Problem Reports

Fast radio bursts (FRBs) are millisecond-duration, bright radio transients of extragalactic origin. The Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope’s CHIME/FRB instrument and other radio telescopes across the globe have detected hundreds of FRBs. Their origins are a mystery. Precise localization within the host is critical to distinguish between progenitor models. This can be achieved through Very Long Baseline Interferometry (VLBI). Until now, VLBI localizations have only been carried out in targeted follow-up observations of some repeating sources which comprise a small fraction of the FRBs.

For this work, an interferometric array of 6m dishes was constructed at the Green …

Deep Radio Observations And The Role Of The Cosmic Web In Galaxy Evolution, Nicholas M. Luber

Graduate Theses, Dissertations, and Problem Reports

A current open question in the evolution of galaxies, is what are the physical mechanisms that cut off galaxies from their primordial gas reservoirs, resulting in the end of their star-formation capabilities? Recent observational programs have shown that the properties of galaxies show dependencies on their placement within the large-scale structure (LSS) of the universe. These observations have motivated recent developments in theoretical work that have shown how a galaxy's interaction with the LSS may impact its connection to primordial gas supply, and ability to continue to accrete gas, the fundamental ingredient in star-formation.

In order to investigate the role …

Impact Of Radio Frequency Interference And Real-Time Spectral Kurtosis Mitigation, Evan T. Smith

Graduate Theses, Dissertations, and Problem Reports

We catalog the ubiquity of Radio Frequency Interference (RFI) plaguing every modern radio telescope and investigate several ways to mitigate it in order to create better science-ready data products for astronomers. There are a myriad of possible RFI sources, including satellite uplinks and downlinks, cellular communications, air traffic radar, and natural sources such as lightning. Real-time RFI mitigation strategies must take these RFI characteristics into account, as the interfering signals can look significantly different at very high time and frequency resolutions.

We examine Spectral Kurtosis (SK) as a real-time statistical RFI detection method, and compare its flagging efficacy against simulated …

Deeply Learning Deep Inelastic Scattering Kinematics, Markus Diefenthaler, Abdullah Farhat, Andrii Verbytskyi, Yuesheng Xu

Mathematics & Statistics Faculty Publications

We study the use of deep learning techniques to reconstruct the kinematics of the neutral current deep inelastic scattering (DIS) process in electron–proton collisions. In particular, we use simulated data from the ZEUS experiment at the HERA accelerator facility, and train deep neural networks to reconstruct the kinematic variables Q² and x. Our approach is based on the information used in the classical construction methods, the measurements of the scattered lepton, and the hadronic final state in the detector, but is enhanced through correlations and patterns revealed with the simulated data sets. We show that, with the appropriate selection …

Spectral Characterization And Age Of The Moon And Primitive Asteroids, Vanessa Lowry

Electronic Theses and Dissertations, 2020-2023

In this dissertation work we sought to answer questions about the age, composition, and origin of planetary bodies. We implemented multiple approaches to answer these questions. To determine the age of the Clarissa asteroid family we implemented a modified version of SWIFT: a Solar System integration software package by Levison & Duncan (1994) to account for gravitational as well as thermal perturbations. This work constrained the age of the Clarissa asteroid family to be 56 ± 6 My. Next, we used a sum to one constraint weighted least squares (STO WLS) modeling approach to model thermal infrared (TIR) spectra of …

Beyond The Local Volume. I. Surface Densities Of Ultracool Dwarfs In Deep Hst/Wfc3 Parallel Fields, Christian Aganze, Adam J. Burgasser, Mathew Malkan, Christopher A. Theissen, Roberto A. Tejada Arevalo, Chih-Chun Hsu, Daniella C. Bardalez Gagliuffi, Russell E. Ryan Jr., Benne Holwerda

Faculty and Staff Scholarship

Ultracool dwarf stars and brown dwarfs provide a unique probe of large-scale Galactic structure and evolution; however, until recently spectroscopic samples of sufficient size, depth, and fidelity have been unavailable. Here, we present the identification of 164 M7-T9 ultracool dwarfs in 0.6 deg2 of deep, low-resolution, near-infrared spectroscopic data obtained with the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) instrument as part of the WFC3 Infrared Spectroscopic Parallel Survey and the 3D-HST survey. We describe the methodology by which we isolate ultracool dwarf candidates from over 200,000 spectra, and show that selection by machine-learning classification is superior to …

The Kepler Problem On Complex And Pseudo-Riemannian Manifolds, Michael R. Astwood

Theses and Dissertations (Comprehensive)

The motion of objects in the sky has captured the attention of scientists and mathematicians since classical times. The problem of determining their motion has been dubbed the Kepler problem, and has since been generalized into an abstract problem of dynamical systems. In particular, the question of whether a classical system produces closed and bounded orbits is of importance even to modern mathematical physics, since these systems can often be analysed by hand. The aforementioned question was originally studied by Bertrand in the context of celestial mechanics, and is therefore referred to as the Bertrand problem. We investigate the qualitative …

The Octagon At Large M, Riccardo Argurio, Matteo Bertolini, Sebastían Franco, Eduardo García-Valdecasas, Shani Meynet, Antoine Pasternak, Valdo Tatitscheff

Publications and Research

Recently, the first instance of a model of D-branes at Calabi-Yau singularities where supersymmetry is broken dynamically into stable vacua has been proposed. This construction was based on a system of N regular and M = 1 fractional branes placed at the tip of the so-called (orientifolded) Octagon singularity. In this paper we show that this model admits a large M generalization, having the same low energy effective dynamics. This opens up the possibility that the effect on geometry is smooth, and amenable to describing the gauge theory all along the RG flow, including the deep IR, in terms of …

Superluminal Propagation On A Moving Braneworld, Brian Greene, Daniel Kabat, Janna Levin, Arjun S. Menon

Publications and Research

We consider a braneworld scenario in the simplest setting, M₄ × S¹, with a four-dimensional (4D) Minkowski metric induced on the brane, and establish the possibility of superluminal propagation. If the brane is at rest, the 4D Lorentz symmetry of the brane is exact, but if the brane is in motion, it is broken globally by the compactification. By measuring bulk fields, an observer on the brane sees a slice through a higher-dimensional field profile, which carries an imprint of the extra dimensions even when the brane is at rest. If the brane is in motion, we …

Milky Way Morphology Probed By 6d Astrometric Data From The Gaia Space Telescope, Joshua Taylor Harry

Theses and Dissertations--Physics and Astronomy

At varying height above and below the plane of the Milky Way, I have used astrometric methods to classify stars of different galactic components of the Milky Way - the thin disk, thick disk, and stellar halo. This work complements prior study of Milky Way sub-structure - notably involving number density and/or pairwise correlations - which demonstrate non-steady state effects in the galaxy, such as axial/north-south symmetry breaking or more complex phenomena like the Gaia snail. This has motivated my exploration of stellar population changes with height about the Milky Way mid-plane, and the study of symmetry in such changes …

Machine Learning And Computer Vision In Solar Physics, Haodi Jiang

Dissertations

In the recent decades, the difficult task of understanding and predicting violent solar eruptions and their terrestrial impacts has become a strategic national priority, as it affects the life of human beings, including communication, transportation, the power grid, national defense, space travel, and more. This dissertation explores new machine learning and computer vision techniques to tackle this difficult task. Specifically, the dissertation addresses four interrelated problems in solar physics: magnetic flux tracking, fibril tracing, Stokes inversion and vector magnetogram generation.

First, the dissertation presents a new deep learning method, named SolarUnet, to identify and track solar magnetic flux elements in …

The Sonora Substellar Atmosphere Models. Ii. Cholla: A Grid Of Cloud-Free, Solar Metallicity Models In Chemical Disequilibrium For The Jwst Era, Theodora Karalidi, Mark Marley, Jonathan J. Fortney, Caroline Morley, Didier Saumon, Roxana Lupu, Channon Visscher, Richard Freedman

Faculty Work Comprehensive List

Exoplanet and brown dwarf atmospheres commonly show signs of disequilibrium chemistry. In the James Webb Space Telescope (JWST) era, high-resolution spectra of directly imaged exoplanets will allow the characterization of their atmospheres in more detail, and allow systematic tests for the presence of chemical species that deviate from thermochemical equilibrium in these atmospheres. Constraining the presence of disequilibrium chemistry in these atmospheres as a function of parameters such as their effective temperature and surface gravity will allow us to place better constraints on the physics governing these atmospheres. This paper is part of a series of works presenting the Sonora …

Solution-Processed Flexible Broadband Zno Photodetector Modified By Ag Nanoparticles, N. P. Klochko, K. S. Klepikova, I. V. Khrypunova, V. R. Kopach, I. I. Tyukhov, S. I. Petrushenko, S. V. Dukarov, V. M. Sukhov, M. V. Kirichenko, A. L. Khrypunova

Faculty Research, Scholarly, and Creative Activity

In this work, we present flexible broadband photodetectors (PDs) fabricated by a deposition of nanostructured zinc oxide (ZnO) films on polyimide (PI) substrates by using cheap and scalable aqueous method Successive Ionic Layer Adsorption and Reaction (SILAR). In order to increase the long-wavelength absorption of the nanostructured ZnO layer, we created its intrinsic defects, including oxygen vacancies by post-treatment at 300 °C in vacuum and thus the light-sensitive material ZnO/PI was obtained. Then we applied silver nanoparticles (Ag NPs) from a silver sol onto a nanostructured ZnO film, which were visualized using SEM in the form of spheres up to …

Measurement Of Differential Branching Fractions Of Inclusive B →Xuℓ+Νℓ Decays, L. Cao, W. Sutcliffe, R. Van Tonder, F. U. Bernlochner, I. Adachi, H. Aihara, D. M. Asner, T. Aushev, R. Ayad, V. Babu, S. Bahinipati, P. Behera, K. Belous, J. Bennett, M. Bessner, T. Bilka, J. Biswal, A. Bobrov, M. Bračko

Faculty and Student Publications

The first measurements of differential branching fractions of inclusive semileptonic B→Xuℓ+νℓ decays are performed using the full Belle data set of 711 fb-1 of integrated luminosity at the (4S) resonance and for ℓ=e, μ. With the availability of these measurements, new avenues for future shape-function model-independent determinations of the Cabibbo-Kobayashi-Maskawa matrix element |Vub| can be pursued to gain new insights in the existing tension with respect to exclusive determinations. The differential branching fractions are reported as a function of the lepton energy, the four-momentum-transfer squared, light-cone momenta, the hadronic mass, and the hadronic mass squared. They are obtained by subtracting …

All-Sky Search For Short Gravitational-Wave Bursts In The Third Advanced Ligo And Advanced Virgo Run, R. Abbott, T. Abbott, F. Acernese, K. Ackley, Teviet Creighton, Mario C. Diaz, F. Llamas, Soma Mukherjee, Volker Quetschke, Wenhui Wang

Physics and Astronomy Faculty Publications and Presentations

This paper presents the results of a search for generic short-duration gravitational-wave transients in data from the third observing run of Advanced LIGO and Advanced Virgo. Transients with durations of milliseconds to a few seconds in the 24–4096 Hz frequency band are targeted by the search, with no assumptions made regarding the incoming signal direction, polarization, or morphology. Gravitational waves from compact binary coalescences that have been identified by other targeted analyses are detected, but no statistically significant evidence for other gravitational wave bursts is found. Sensitivities to a variety of signals are presented. These include updated upper limits on …

All I Want For Christmas..., Channon Visscher

Faculty Work Comprehensive List

"JWST [the James Webb Space Telescope] will let us see clearer and further into the ancient and beautiful story of creation."

Posting about new developments in spacecraft from In All Things - an online journal for critical reflection on faith, culture, art, and every ordinary-yet-graced square inch of God’s creation.

https://inallthings.org/all-i-want-for-christmas/

The North Dakota Dual Aurora Camera (Noddac), A Student-Led Citizen Science Project: One-Year Retrospective, Future Developments, And Scientific Potential, Vincent Ledvina, Elizabeth Macdonald, Steven Collins, Michael Mccormack, Timothy Young, Wayne Barkhouse

Arts & Sciences Undergraduate Showcase

The North Dakota Dual Aurora Camera (NoDDAC) is a student-led project operated in conjunction with the University of North Dakota (UND), the LiveAuroraNetwork, and Aurorasaurus citizen science. Aurora cameras are valuable tools for aurora chasers, and scientists, providing ground-truth visual data to gauge auroral activity, yet at midlatitudes, these facilities are few in number. Deploying aurora cameras in these areas provides a valuable resource for aurora-chasing communities, but also demonstrates scientific merit as the analysis of rare phenomena, such as STEVEs, benefit from multiple geographic observations. What makes this project unique is the student initiative being based at a university …

Cuny York College–Hosted Nasa Stem Outreach Program Graduates Over 30,000 Students – The Legacy Continues Amidst The Covid-19 Pandemic, Nazrul I. Khandaker

Publications and Research

The NASA MUREP (Minority University Research and Education Project) and SEMAA (Science, Engineering, Mathematics and Aerospace Academy) at York College CUNY (City University of New York), borough of Queens, New York City, recently earned a distinction by graduating over 30,000 underrepresented minority students since 1999 with the culmination of the fall 2021 session! African American students are leading the graduates, followed by Hispanic and Asian students being almost equal in proportion. The primary objective of both MAA (MUREP Aerospace Academy) and SEMAA is getting underrepresented minority students exposure to innovative STEM content and prepare many of them to enter higher …

Stability And Mechanical Properties Of W1-X Mox B4.2 (X=0.0-1.0) From First Principles, Weiguang Gong, Rui Xu, Xuecheng Shao, Quan Li, Changfeng Chen

Physics & Astronomy Faculty Research

Heavy transition-metal tetraborides (e.g., tungsten tetraboride, molybdenum tetraboride, and molybdenum-doped tungsten tetraboride) exhibit superior mechanical properties, but solving their complex crystal structures has been a long-standing challenge. Recent experimental x-ray and neutron diffraction measurements combined with first-principles structural searches have identified a complex structure model for tungsten tetraboride that contains a boron trimer as an unusual structural unit with a stoichiometry of 1:4.2. In this paper, we expand the study to binary MoB4.2 and ternary W1-xMoxB4.2 (x=0.0-1.0) compounds to assess their thermodynamic stability and mechanical properties using a tailor-designed crystal structure search method in conjunction with first-principles energetic calculations. Our …

A Note From The Co-Editors, Fayth Schutter

Ideas: Exhibit Catalog for the Honors College Visiting Scholars Series

An introduction to the fourth issue of the third volume of Ideas Magazine, concerning the career and thoughts of Col. Richard Covey.

Brown Dwarf Atmospheres At High Cadence And Spectral Resolution: A Speed Limit On Brown Dwarf Rotation And A Spectroscopic Atlas Of A 1050 K Atmosphere, Megan E. Tannock

Electronic Thesis and Dissertation Repository

Brown dwarfs are sub-stellar objects that form like stars but are not sufficiently massive to sustain hydrogen fusion in their cores. Characterized by cool, molecule-rich atmospheres, brown dwarfs demonstrate great diversity in spectroscopic appearance and share many properties with giant exoplanets. In this thesis I present two investigations: the first is a detailed photometric and spectroscopic study of the three most rapidly rotating brown dwarfs. The second examines a spectrum of a cool brown dwarf at unprecedented spectral resolution and signal-to-noise ratio to study the accuracy of theoretical model photospheres.

Photometric monitoring of brown dwarfs has revealed that periodic variability …