Andrea Munroe: Verifying Jet Trigger Efficiencies for ATLAS Run III
On July 5th, 2022, the Large Hadron Collider (LHC) at CERN began Run III of proton-proton collisions at 13.6 TeV to produce novel subatomic particles. The ATLAS experiment is now taking data with hardware and software updated during the long shutdown. This project aimed to validate the efficiency and performance of triggers for jets so that analysts can separate new physics from artifacts of a new data-taking methodology. Trigger efficiencies were recorded for hardware-based Level 1 (L1) jet triggers using the ATLAS analysis packages. Operation of probe triggers was compared to the output of known reference triggers. Measurements of L1 jet efficiencies suggest that new algorithms are effective in reducing jet signal pileup. Data analysis steps need further cleaning.
Kathleen Connick: The Application of Neural Networks in Stellar Classification
Innovations in technological capabilities and processes, as well as an associated increase of astronomical data, presents the need for a more efficient way to process this data. Deep Learning and Machine Learning have progressed to accommodate these needs and have proven to be useful techniques to build effective models for analysis of this new data. In this specific case, we are utilizing Neural Networks within ML/DL to create a better system for use in stellar spectroscopy. Having already worked with Principal Component Analysis (PCA) and Sliced Inverse Regression (SIR) as tools to process the data and having utilized Convolutional Neural Network (CNN) to determine optimal hyperparameters, we turn our focus now to constructing the best network architecture, testing both CNN and fully connected neural networks. We want to build the best network possible in combination with the previously determined optimal hyperparameters in order to find the most efficient and accurate derivations for our desired stellar parameters: effective temperature (Teff), surface gravity (logg), projected equatorial rotational velocity (vsini), and metallicity ([M/H]).
Thresa Kelly: Multiwavelength Comparison of X-ray and Infrared Selected Active Galactic Nuclei
Active galactic nuclei (AGNs) have different emission spectra depending on their physical characteristics. Using only one wavelength region to identify an AGN may miss sources with unique characteristics. In this work, we compare the multiwavelength properties of X-ray and mid-IR selected AGN in the COSMOS field. Our X-ray sample includes all sources with an intrinsic 0.5-10 keV X-ray luminosity greater than 10^43 erg/s. We define our mid-infrared (MIR) AGN sample using the four Spitzer/IRAC channels. We find that 70% of X-ray-selected AGN are not identified as AGN using their IR colors, and 40% of IR-selected AGN do not meet the X-ray luminosity threshold. We find that MIR-selected AGNs are more luminous in the MIR than X-ray-selected AGNs, but have a similar range of UV emissions. Sources that satisfy both IR and X-ray selection criteria are more luminous across their entire spectra, in general.
Yashasvi Moon: Using Fractal Dimension to identify noise in LIGO Interferometer
This paper uses a new method to analyze noise and gravitational waves in the LIGO detector. LIGO detects many signals. A particular fractal dimension is associated with a signal. We can compute fractal dimension of a signal obtained by LIGO. Fractal dimension can identify the section with more noise and glitches. It can help identify noises due to earthquakes and predict when the detector is going into lock loss.
Anne Lashbrook: Study of the Two Lepton Channel Sensitivity in Low-pTmiss Top Squark Searches
Supersymmetry is a mathematical symmetry that makes identical the equations for force and matter, presenting a relation between fermions and bosons. There exist many new physical models that incorporate supersymmetry and also characterize it with R-parity violation. R-parity is a property of subatomic particles in which all known particles have positive R-parity and supersymmetric particles negative. R-parity violating (RPV) supersymmetric models envision proton-proton collisions resulting in low missing transverse momentum and a spray of jets consisting of quarks and gluons. This research analyzes data from CERN’s CMS experiment for signs of new physics. This is accomplished using reconstructed collision events with at least six jets and two leptons at √𝑠=13 𝑇𝑒𝑉. Dominant backgrounds are identified and analyzed for additional data selections to further minimize events of interest. RPV signals are analyzed at 300 GeV and 800 GeV. The two lepton channel sensitivity is refined for future analyses.
Caroline Witt: Merger Histories of Inner Planets Under the Influence of Distant Giant Planets
Some exoplanet systems may harbor massive planets at Jupiter-like orbit distances. Here we compare planetary merger histories in the innermost 1 AU with and without the presence of a Jupiter mass planet orbiting 5 AU away from the host star. We perform dynamical simulations of the giant impact phase of planet formation. These include eccentricity damping from a residual gas disk for 1 Myr followed by 27 Myr of subsequent evolution post disk dispersal using initial conditions for the planetary embryos that result in the diversity of super-Earth systems observed by Kepler. From a preliminary subset of these simulations, we find that systems containing a massive outer planet are more likely to undergo mergers between inner planets after the gaseous disk has dispersed.
Julia Herkert: Unraveling Chaos - How Cloud Seeding Could Impact Climate Change
Gaining further understanding of cloud behavior, one of the most chaotic systems in Earth's atmosphere, is essential in studying the future of Climate Change. Chaos theory, more commonly known as the butterfly effect, dictates that a chaotic system is one in which a slight change in the system’s conditions could lead to an extreme variation in the system’s resulting behavior. Cloud seeding marine stratocumulus clouds by injecting sea salt aerosols into Earth’s atmosphere is a promising method for lowering global temperatures. However, due to the chaotic nature of cloud behavior, the changes in the atmosphere resulting from cloud seeding could lead to detrimental effects on the climate such as droughts, floods, and other natural disasters. This project uses the Community Earth System Model (CESM) to safely study the benefits cloud seeding at varying latitudes may have on Earth’s climate, while also reviewing the negative effects that manipulating these chaotic systems may present in the future.
A. Meenakshi McNamara: Ekpyrosis in a Quantum Gravitational Anisotropic Bounce
In loop quantum cosmology, an application of loop quantum gravity, the big bang singularity is resolved by replacement with a quantum bounce. Any viable theory must result in an isotropic macroscopic universe, but anisotropies are expected to play an important role near the bounce. Here we quantitatively investigate the effect of an Ekpyrotic potential on the anisotropy in Bianchi-I models using the framework of loop quantum cosmology through comparing the values of the energy density and anisotropic shear at the bounce for universes with the Ekpyrotic potential as well as universes with a massless scalar field. We find a novel relationship between the shear and energy density at the bounce, which results in the Ekpyrotic potential increasing the energy density at the bounce under most initial conditions and often decreasing the anisotropic shear, so that the matter component dominates over the anisotropies at the bounce more often.
Morgan Cassidy: CP Violating Top-Higgs Coupling at the Future Muon Collider
We study a new source of CP violation by proposing a CP violating top-Higgs coupling. We study three processes, and show how the production rate of our signals depend on the collider energy. After presenting the production rate's dependence on the magnitude of the CP phase at different energies, we give bounds on the CP phase at the 95% confidence level for a muon collider operating at 1, 3, 10, and 30 TeV. We compare our results for the muon collider to results found for other proposed colliders.
Emily Nelson: Determining the Longitudinal Double-Spin Asymmetry (A_LL) for pi0 and eta Production from STAR 2013 Endcap Calorimeter Data
The Solenoidal Tracker at RHIC (STAR) located at Brookhaven National Laboratory uses longitudinally polarized proton-proton collisions to study the gluon spin contribution to the known proton spin of 1/2 h-bar. The relative contributions of the quarks and gluons to the spin of the proton remain uncertain. Using data from the 2013 longitudinally polarized proton-proton collisions we study the asymmetry of proton spin-dependent production of neutral pions (pi0s) from these collisions. pi0s rapidly (8.5 * 10-17s) decay into 2 photons that are detected by the Endcap Electromagnetic Calorimeter. By comparing the number of pi0s produced when protons collide with different helicities, the asymmetry of pi0 production (A_LL), which can be related to the contribution of the gluon spin to the spin of the proton, can be measured. The two-photon invariant mass spectrum is reconstructed and then fit using a skewed Gaussian function to represent the pi0 signal and a Chebyshev function to characterize the background. Various checks must be made to assure the quality of the data being analyzed. The status of this analysis will be presented.
Olivia Lazorik: Harnessing Quantum Thermometry in Biological Systems
Quantum sensors based on solid-state spin defects have recently emerged as probes for a myriad of signals, including magnetic field, strain, and temperature. In fact, nanodiamond with nitrogen-vacancy (NV) centers has been a versatile tool to explore various phenomena in physical and biological systems. Our group is interested in using the nanodiamond as a quantum sensor to probe the thermal distribution inside of a yeast cell. We have been experimenting with nanodiamonds with NV centers in various dimensions in a wide-field optical setup. We primarily use electron-spin resonance (ESR) spectrum as a reflection of signals probed by nanodiamonds. On a bulk diamond with shallow NV centers embedded near the surface, we observed the strain effect on the ESR spectrum. Diamond polishing can achieve surface roughness under 1 nm, and as a result, the surface is highly strained. Recently we have been using 140 nm diamonds to probe the local temperature in the yeast cell. We have observed that the nanodiamond has been a promising sensor in the biological environment of a yeast cell. The local thermal distribution can be unveiled with control of the movement of the diamond using an optical tweezer.
Simarpreet Girn: Investigating Outcomes of Inner Planet Formation Influenced by a Jupiter-Like Perturber
Our solar system is unique because we have no rocky planets larger than Earth yet smaller than our ice giants called super-Earths. Many exoplanets that are super-Earths have been discovered in many other planetary systems outside of our solar system. This poses the question of what influences the formation of these super-Earths. For this project, we focused on the influence of a massive planet on inner-planet formation. We ran 36 dynamical simulations where we added a Jupiter-like planet 5 AU away. We analyzed the multiplicity, eccentricity, and average planet masses of inner planets formed and compared them to simulations without a Jupiter-like planet present. The simulations were conducted in two stages: 1) during the residual disk phase with damped orbit eccentricities and 2) post-disk dispersal with subsequent dynamical evolution. From the simulations, we found that eccentricities for both cases seemed slightly to increase from Stage 1 to Stage 2. The multiplicity of planets decreased during the disk and post-disk dispersal stages due to mergers, except for systems of planets in resonant chains, in which case no mergers occurred after disk dispersal. We also looked at the average masses of the planets between these two cases but found no definite trend of whether the perturber is causing more mergers.
Cassidy Metzger: Long-Term X-Ray Variability in Active Galactic Nuclei MASX J20082452-444095: Studying Accretion Onto An Intermediate Mass Black Hole
Active Galactic Nuclei (AGN) are objects with incredibly high energy densities that can be found at the center of galaxies. While there are many different types of AGNs, they can generally be depicted as supermassive black holes with accretion disks that emit a spectrum of radiation, often peaking in the optical-ultraviolet waveband. These accretion disks, comprised of gas and dust that are accreting onto the black hole, can launch relativistic jets that accelerate particles away from the central black holes emitting radiation in all wavebands. This presentation focuses on the Seyfert 1 galaxy 2MASX J20082452-444095, which contains an intermediate-mass black hole (IMBH), and utilizes X-ray observations from the Neil Gehrels Swift Observatory to search for long-term variability in its X-ray emission. Two previous AGN surveys have studied this object, both of which discussed the inverse relationship between X-ray variability and a black hole’s mass. They both saw that this object was highly variable on short time scales and had a large accretion rate. Given this information, 2MASX J20082452-444095 presents as an excellent candidate for an AGN that contains a growing black hole. This presentation looks into a dataset spanning several years to elaborate further on the implications that the study of 2MASX J20082452-444095 and other IMBHs may have on the field of high-energy astrophysics.
Samantha Lund: Optimization of Air Light Guides for New ATLAS and CMS Zero Degree Calorimeters for LHC High Luminosity Operations
At the Large Hadron Collider (LHC) at CERN, 2022 Run 3 physics data taking has just begun. Nevertheless, preparations for anticipated 2029 Run 4 are already underway. Following Run 3, the LHC will undergo its final transformation into the High Luminosity LHC (HL-LHC), allowing Run 4 to experience a collision rate five times higher than the LHC’s original design. These upgrades will allow us to investigate the Standard Model with increased precision, better identify new phenomena, and greatly enhance the physics potential of this experiment. Run 4 will be preceded by Long Shutdown 3 (LS3), a three year shutdown for the replacement, repair, and upgrade of both hardware and software within the LHC system. Many instruments will be updated, the ATLAS Zero Degree Calorimeter (ZDC) among them. The ATLAS ZDC, located within the Target Absorber for Neutrals (TAN), lies approximately 140 meters downstream from the collision site, where it is responsible for determining the energy of spectator neutrons from each collision event. This measurement allows us to determine the approximate quantity of spectators, thus providing insight into the event’s centrality. The University of Illinois at Urbana Champaign collaborates on the maintenance and development of the ZDC, which is composed of an electromagnetic (EM) module, a Rotation Plane Detector (RPD), and three hadronic (HAD) modules. These modules use tungsten absorbers and fused-silica Cherenkov radiators to transform high energy particles into light, which can then be read by Photo-Mulitplier Tubes (PMTs) and converted into an electric analog signal. Directing the light from the fused-silica rod and into the PMTs is done through a reflective light guide. In this contribution, we explore new candidates for light guides to be used in the EM and HAD modules of the ZDC during Run 4. In particular, we will discuss the results of simulation and comparative experimentation used to investigate the efficiency and uniformity of light guides with various geometries.
Tegan Thomas: Interactive 3D Visualization of Neutron Star Magnetic Fields
Many astrophysicists suspect that magnetars are the source of Fast Radio Bursts (FRBs). However, the exact mechanisms of this process are still hard to understand, especially in 3D. Using the K3D python package, I sought to create a procedure to produce interactive 3D visualizations of magnetic fields. This procedure could be used to both examine the plasma dynamics outside neutron stars that may be relevant for FRBs and improve the general public's understanding of magnetic fields. The procedure involves performing the Euler method over a double for loop to get coordinates. K3D is then used to plot the coordinates. Ideally, you should be able to input the equations for the x, y, & z components of the magnetic field and produce a 3D visualization. Using the equations for a magnetic dipole, I used the procedure to create a 3D graph of the field lines, which was relatively accurate in comparison to the graph produced from the exact equations. It is good to note that there are multiple ways to numerically integrate field lines, with other techniques like the improved Euler method yielding more accurate estimations. I want to look into using these alternative techniques to improve my procedure.
Bhavya Pardasani: Spatially Resolved Properties of Post-starburst Galaxies
Star-forming galaxies can reach quiescence via transition through the short post-starburst phase. During this evolution, the galaxies undergo rapid transitions due to mergers that consequently affect their disk kinematics and star-formation rate. In this work, we analyze the kinematics of post-starburst galaxies (PSBs) and place them in context with the early-type galaxies (ETGs) to infer their merger histories from likely changes in their kinematics. We analyze spatially resolved properties, like angular momentum of 92 PSBs from the MaNGA survey to study their kinematics. We model the angular momentum at half-light radius as a function of stellar mass and ellipticity at half-light radius to identify trends that are similar across both the samples. We find that the PSB sample has ~ 5.43% (5/92) slow rotators, which is less than the ~13.86% (36/260) of slow rotators in the ETG sample. This implies that for the PSBs to evolve into the ETGs, they must lose some angular momentum. From our analysis of angular momentum as a function of mass-weighted and luminosity-weighted ages, we find that the PSBs generally lose angular momentum as they grow older and evolve into the ETGs. Thus, the ETGs have lived for a longer time while continuously losing their angular momentum as they evolve. These results lead us to conclude that the PSBs evolving into ETGs probably underwent multiple dry merger events that helped them shed off the excess momentum without causing a burst of star-formation.
Kalista Wayt: Identifying Glitches in LIGO Gravitational Wave Data with Machine Learning Algorithms
The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a ground-based interferometer used to detect gravitational waves from some of the most spectacular astrophysical events in the Universe. Gravitational waves from these objects manifest as nearly imperceptible changes in distance (strain), requiring an unparalleled level of sensitivity in order to distinguish such signals from a noisy background. Our world is noisy, and the noises we encounter are normal everyday occurrences that have little to no effect on our lives, but with LIGO, this noise does matter. LIGO's main strain channel is contaminated with loud and transient noise artifacts, called "glitches," which has required LIGO to use instruments dedicated to tracking possible causes of noise. This information is recorded in auxiliary channels. My overall goal is to develop a machine learning algorithm (MLA) that uses information from the auxiliary channels to perform real-time predictions about the presence of glitches in the strain data. Previous attempts at constructing an MLA had large variability in effectiveness daily. In this poster, I will show the results of our newest attempt to improve our ability to predict glitches over an observing run by using a hierarchal method using the auxiliary subsystems to account for the changing nature of glitches over time. I will also present our proposition to improve the MLA by creating the hierarchal method using glitch types as the subcategories of the hierarchy.
Anna Przybyl: A Novel Reaction Plane Detector for the ATLAS Experiment
The CERN LHC began Run 3 physics data taking in July 2022. During the three years of Long Shutdown 2 (LS2), LHC experiments had the opportunity to refurbish their existing apparatus, as well as expand their physics capabilities with the implementation of new sub-systems. In this period, the Nuclear Physics Laboratory at the University of Illinois at Urbana-Champaign (UIUC) has developed a novel reaction plane detector (RPD) to be installed in the LHC together with the ATLAS Zero Degree Calorimeter (ZDC) for heavy ion (HI) data taking. The detector consists of 256 fused silica fibers that are grouped in a total of 16 channels and read out by Photo-Multiplier Tubes (PMTs). In HI collisions, the correlated transverse deflection of spectator neutrons is directly related to the reaction plane (RP) characterizing the event. The RPD enables the RP measurement in HI collisions by mapping the transverse profile of the showers generated by the spectators in the ZDC. In this contribution, we present the design of the new ATLAS RPD built at UIUC for the Run 3 HI program. Details about detector design, radiation hardness and integration with ATLAS DAQ system and electronics will be discussed. The RPD was tested at the SPS in July and initial results from the test will be shown.
Mae Hagelgans: Simulating CHIME Fast Radio Burst Populations
While surveys like the Canadian Hydrogen Intensity Mapping Experiment (CHIME) have discovered hundreds of fast radio bursts (FRBs), there is uncertainty about their origins. We implemented a population synthesis program called frbpoppy to create simulations to understand underlying FRB populations. We were interested in understanding CHIME populations as a new catalog of data will be released soon. We created simulations that unveil characteristics of both one-off and repeating FRB populations. Preliminary results indicate CHIME FRBs can be modeled well within the framework of frbpoppy. The one-off model can account for the varying luminosities and dispersion measures we expect to find in FRBs. Markov Chain Monte Carlo (MCMC) simulations allow us to systematically explore multidimensional parameter space and optimize all our intrinsic FRB parameter distributions. An MCMC is being implemented into frbpoppy. Our goal is to produce marginalized probability density functions of the various parameters involved, including but not limited to the emission range, luminosity, dispersion measure, maximum redshift, and pulse width. Alongside this, for repeater FRBs, we made a prediction using Poisson statistics and then simulated our prediction with frbpoppy. Within the framework of this toy model, we expect the total number of repeating FRBs detectable to CHIME to saturate in the range of 30-40 sources in total (22 are currently known). However, we anticipate that repeaters may not follow a Poisson distribution. More work needs to be done to improve our models, and we eagerly await upcoming data releases from CHIME to test our predictions.
Leeanne Smith: Impact of Near-Earth Supernovae on Oort Cloud Objects
A supernova occurs when a massive star reaches the end of its life and explodes. Although supernovae can be detected as soon as the light they release reaches Earth, the blast wave travels significantly slower. One region that could be affected is the Oort Cloud, a spherical shell composed of comets surrounding the solar system, starting at 5000 astronomical units (AU) and extending to 40000 AU away from the sun. Oort Cloud objects travel at slower speeds and can be susceptible to being kicked into another orbit by a supernova’s blast wave. We simulated the effect of the blast wave on 6 orbital parameters: • Semi-major Axis • Eccentricity • Argument of Periapsis • Longitude of the Ascending Node • Angle of Inclination • True Anomaly These were generated randomly and assigned a radius between 10-6 and 104 meters. We then added a "kick", which was calculated by assuming the supernova blast wave imparted a certain amount of kinetic energy on the comets. We then used the kick to find the new orbits of the comets. The "kick" imparted by the blast wave equal to v_kick = sqrt(3/(8*pi) * E_SN/(rho_c*r_c*d_SN**2) and used that to calculate the new values. This was repeated for 100,000 comets.
Emily Chen: Active stabilization system for a low-loss, free-space optical quantum memory
Error-free and long-lived quantum memories are a useful resource for quantum information science and technology because of their ability to synchronize independent and probabilistic quantum processes. Various quantum memory architectures currently exist, including designs based on two-photon off-resonant cascaded absorption (ORCA), electromagnetically induced transparency (EIT), atomic frequency comb (AFC), and a hybrid approach of an atomic ensemble memory/optical delay line. We are developing a quantum memory that makes use of an optical delay line for storage, where a multipass-modified Herriott cell creates an optical loop that stores and releases a photon at programmable intervals. Specifically, the delay line offers significantly higher efficiency rates, along with better fidelity, bandwidth, and time bandwidth. Since the modified Herriott cell can have an effective optical path length of hundreds of meters or more, this project aims to develop a robust active feedback system to maintain alignment in the optical cavity.
Healey Kogan: Fabry-Pérot Cavity Experiment
Recently, optical tweezers have become a widespread tool used to capture and trap atoms. However, it has been difficult to use these tweezers to develop entangled atoms arrays. One solution to these issues is using cavities in conjunction with tweezers. Fabry-Pérot cavities require precision alignment and testing. Thus, we design and construct a Fabry-Pérot test cavity to understand how it functions with laser beams. While light currently does not exit our test cavity, we continue to modify it and learn how it works.