Physical Sciences and Mathematics Commons^™

Life Beyond The Horizon: The Universe Was Born In A Black Hole, Zahria Patrick

Undergraduate Research Symposium

It is a widely accepted fact that obtaining information about a black hole is a near-impossible task without being stretched like a spaghetti noodle and trapped in one due to its strong gravitational pull. If the universe exists in a black hole, however, it will mean that it could be possible to survive after crossing its inescapable borders. As surprising as all of this may seem, this theory has existed for quite a while amongst a few different physicists. One person that has shed light on and expanded people’s knowledge of this frightening theory is theoretical physicist, Nikodem Poplawski. The …

Extension Of The Lux-Zeplin Nr Background To 600 Phd, Jackson Codd

Macalester Journal of Physics and Astronomy

In June 2022, the LUX-ZEPLIN collaboration released its first results, with the
most precise measurements of any direct dark matter detector. The findings were
calculated using the expected spin-independent WIMP-nucleon interaction model,
which would result in small energies deposited in the detector. Therefore, the
background of non-dark interactions was calculated for events with S1 areas up to
80 phd (Aalbers et al. 2022). In order to increase the sensitivity to high energy
WIMP-nucleon interaction events, as predicted by other models, we extended the
non-dark NR background to events with S1 areas of up to 600 phd. We found a
large …

Calibration Of The Lux-Zeplin Dual-Phase Xenon Time Projection Chamber With Internally Injected Radioisotopes, Christopher D. Nedlik

Doctoral Dissertations

Self-shielding in ton-scale liquid xenon (LXe) detectors presents a unique challenge for calibrating detector response to interactions in the detector's innermost volume. Calibration radioisotopes must be injected directly into the LXe to reach the central volume, where they must either decay away with a short half life or be purified out. We present an overview of, and results from, the prototype source injection system (SIS) developed at the University of Massachusetts Amherst for the LUX-ZEPLIN experiment (LZ). The SIS is designed to refine techniques for the injection and removal of precise activities of various calibration radioisotopes that are useful in …

Signal Yields And Detector Modeling In Xenon Time Projection Chambers, And Results Of An Effective Field Theory Dark Matter Search Using Lux Data, Gregory Ransford Carl Rischbieter

Legacy Theses & Dissertations (2009 - 2024)

The nature of dark matter continues to be one of the biggest remaining mysteries in physics. Astrophysical measurements indicate that dark matter makes up more than a quarter of the Universe's total energy density, and it is well-motivated that dark matter is comprised of Weakly Interacting Massive Particles (WIMPs). Direct detection techniques utilizing liquid and gaseous noble elements have become the primary method of probing the potential non-gravitational interactions between WIMPs and Standard Model matter, with the leading technology being the dual-phase Time Projection Chamber (TPC). The Large Underground Xenon (LUX) and its second-generation successor, LUX-ZEPLIN (LZ), are two xenon …

Image Data Analysis And Design Optimization Of The Snowball Chamber, Yujia Huang

Legacy Theses & Dissertations (2009 - 2024)

Dark Matter is the invisible massive particle that makes up over 26.8 percent of the mass-energy content of the universe. Weakly Interacting Massive Particles, or WIMPs, are one of the candidates of dark matter particles. Many scientists around the world are trying to figure out how to detect detect dark matter using either indirect search, direct production or direct detection experiments. However, due to the lack of evidence of finding WIMPs in direct detection experiments at a large mass scale, a call for investigating WIMPs at a lower mass range is attracting more attention.

Laplace's Equation In Fractional-Dimension Spaces, Kyle Schoener, Gabriele Varieschi

Honors Thesis

The correct way to model gravity is a question in physics whose answer continues to elude our understanding. One major difficulty is the dark matter problem, which exists due to the mass discrepancy between predicted and measured values in our universe. One possible solution to this problem is Modified Newtonian Dynamics (MOND). MOND is an alternative gravity model that modifies Newtonian Dynamics with the hope to avoid the necessity of dark matter.

Dr. Varieschi has done work connecting MOND to Newtonian Fractional-Dimension Gravity—the application of fractional calculus and fractional mechanics to classical gravitation laws. In this formulation, we can consider …

Effective Field Theory Applications: From Dark Matter To Neutrino Nucleon Scattering, Qing Chen

Theses and Dissertations--Physics and Astronomy

Weakly-interacting-massive-particles (WIMPs) are a large class of viable dark matter candidates. We compute cross sections for electroweak-doublet WIMPs scattering on atomic nuclei, at leading and subleading order using heavy WIMP effective field theory. Neutrino-nucleon charged current elastic scattering is an important process in the detectors of long baseline accelerator neutrino oscillation experiments. We compute QED radiative corrections to this process employing soft-collinear effective field theory.

Supercdms: Energy Calibration Of A Ge Hv Particle Detector, Salamong Xiong, Vuk Mandic, Matthew Fritts, Nicholas Mast, Jacob Nelson

Macalester Journal of Physics and Astronomy

The goal of the SuperCDMS collaboration is to directly detect dark matter. Weakly Interacting Massive Particles (WIMPs) are potential candidates. To detect WIMPs, it is important to be able to predict how a Ge/Si particle detector will respond to a dark matter signal. In particular, it is necessary to calibrate the recoil energy measured by these detectors. This paper presents evidence for dark matter, a description of the detector operation, and procedures used to analyze measured data from a SuperCDMS-HV Ge particle detector using Am-241 and a PuBe neutron source. Due to high event rate, criteria were developed to remove …

Dark Matter Production Beyond The Thermal Wimp Paradigm: An Exploration Of Early Matter Domination Scenarios, Jacek Ksawery Osinski

Physics & Astronomy ETDs

In the standard thermal history of the Universe, the energy density is dominated by radiation throughout the postinflationary era, until matter-radiation equality after big bang nucleosynthesis (BBN). However, we currently do not have any observational probes of the pre-BBN period, and radiation domination (RD) is therefore an assumption. Generic early Universe models predict the presence of additional components in the postinflationary Universe which can lead to periods of nonstandard evolution before the onset of BBN. A prominent example of such a period is a phase of early matter domination (EMD) in which the Universe undergoes matter-dominated expansion for a time, …

Pnnl Dark Matter Bubble Chamber Simulation, Carl M. Krutz

STAR Program Research Presentations

Based on observations of interactions between objects on a cosmic scale, scientists have determined that a large percentage (85%) of the universe’s mass is not visible. Weakly Interacting Massive Particles (WIMPs) are one of the primary candidates for this dark matter. Many current projects seek to find WIMPs through various search methods. The PICO dark matter experiment involves observing an underground chamber at SNOLAB for bubbles created when energy in the form of radiation is deposited in a superheated liquid. The group at Pacific Northwest National Lab (PNNL) working on the PICO project seeks to develop improvements to the project’s …

Studying The Properties Of Sf6 Gas Mixtures For Directional Dark Matter Detection, Randy J. Lafler

Physics & Astronomy ETDs

Although dark matter comprises approximately 85\% of the matter content of the universe, direct detection of dark matter remains elusive. As the available parameter space for dark matter candidates is pushed to lower and lower limits, the demand for larger, more sensitive detectors continues to grow. Although upscaling the detector improves the sensitivity, it greatly increases the cost and complexity of the experiment. Even after a dark matter signal is detected, there remains the possibility that an unknown background mimics the dark matter signal. Consequently, verifying the dark matter origin of a detection signal is an issue for any dark …

A Survey Of Dark Matter Candidates And Relations To Particle Physics And General Relativity, Tyler Martell

Honors Program Theses and Projects

Cosmological observations of certain galaxies suggest that the amount of known, measured matter accounted for by the Standard Model of Particle Physics (SM) in those systems is insufficient to account for galactic mechanics (orbital paths and velocities). These observations have led physicists to believe that either General Relativity (GR) is incomplete, or that there exist new sources of yet-to-be detected matter, that may or may not be consistent with SM, called dark matter. Neither GR nor the SM can alone be considered complete theories of the universe for GR is not quantum

mechanical and the SM does not include GR. …

Search For Dark Matter Decay Of The Free Neutron From The Ucna Experiment: N → Χ + E^+E^−, Xiaohui Sun, Edith Adamek, Bruno Allgeier, Matthias A. Blatnik, Thomas J. Bowles, Leah J. Broussard, Matthew A. Brown, Richard Carr, Steven M. Clayton, Chris Cude-Woods, Sonja Currie, Eric B. Dees, Xingxing Ding, Bradley W. Filippone, A. Bello García, Peter Geltenbort, Salajeghe Hasan, Kevin P. Hickerson, J. Todd Hoagland, R. Hong, Gary E. Hogan, Anthony T. Holley, Takeyasu M. Ito, Amanda L. Knecht, Chao-Yu Liu, Jingyang Liu, María Makela, Russel Mammei, J. W. Martin, Dan Melconian, Michael P. Mendenhall, Stephen D. Moore, Charles L. Morris, Sushil Nepal, N. Vahedi Nouri, Robert W. Pattie Jr., A. Pérez Galván, David G. Phillips, Richard H. Picker, Margaret L. Pitt, Blakely A. Plaster, Jana C. Ramsey, R. Barreto Rios, Daniel J. Salvat, Andy Saunders, Walter Sondheim, S. Sjue, Steven Slutsky, Charles Swank, Gyani Swift, E. Tatar, R. Bruce Vogelaar, Brittany Vorndick, Z. Wang, Wanchun Wei, J. Wexler, T. Womack, Christopher Wrede, Andrew R. Young, B. A. Zeck

Robert W. Pattie Jr.

Evolution Of Barred Galaxies In Spinning Dark Matter Halos: High Resolution N-Body Simulations At Dlx, Angela Collier, Isaac Shlosman, Clayton Heller

Commonwealth Computational Summit

Observations show that galaxies are dominated by stellar disks immersed in much more massive, slowly tumbling dark matter (DM) halos. Large fraction of galactic disks, at least 75%, are barred (see Hubble Fork on the right). Stellar bars form either via spontaneous break of axial symmetry or via galaxy interactions.

The formation and evolution of stellar bars is not fully understood. Stellar bar evolution is highly nonlinear and cannot be treated analytically. The main approach to study these disk-halo systems is via numerical simulations, whose goal is to explain why galaxies have such a wide range of morphologies as shown …

Dark Matter Halo Mass Function From Hpc N-Body Simulations, Da Bi, Isaac Shlosman, Emilio Romano-Diaz

Commonwealth Computational Summit

Dark matter (DM) dominates the matter in the Universe. Because of self-gravity, DM collapses and becomes clumpy, building the large-scale hierarchical structures. Baryons assemble within DM potential wells and form galaxies.

Because we can not directly observe DM halos, numerical simulations is the only way one can study their dynamics and other properties. Using N-body simulations, we can obtain the Halo Mass Function (HMF), which provides the abundance of DM halos as a function of their mass. The HMF depends weakly on cosmological redshift and is one of the basic tools in modern cosmology.

We use GIZMO --- a flexible, …

Miniclean Dark Matter Experiment, Juijen Wang

Physics & Astronomy ETDs

Particle Dark Matter is a hypothesis accounting for a number of observed astrophysical phenomena such as the anomalous galactic rotation curves. From these astronomical observation, about 23% of the universe appears to consist of dark matter. Among the possible candidates for dark matter, a plausible one is a Weakly Interacting Massive Particle (WIMP). A particle with the required properties is beyond the standard model of particle physics. The MiniCLEAN experiment is single-phase liquid-argon detector instrumented with 92 photomultiplier tubes placed inside the cryogenic liquid with 4-pi coverage of a 500 kg (150 kg) target (fiducial) mass. For this experiment, PMT …

Searching For Signals Of Dark Matter Decay, Gardner R. Marshall, William Hester

Journal of the South Carolina Academy of Science

Dark matter is believed to make up approximately eighty-three percent of the matter in the universe. Despite its apparent abundance, it has not yet been directly detected, and it is not known what types of particles it is composed of. Efforts to understand what dark matter is made of and how it fits into the Standard Model of particle physics is currently an important and active area of research. In this paper we investigate a method of studying dark matter indirectly by using terrestrial neutrino telescopes to search for signs of dark matter decay. In particular, we study leptonically decaying …

Search For Annihilating Dark Matter In The Sun With 3 Years Of Icecube Data, Karen Andeen

Physics Faculty Research and Publications

We present results from an analysis looking for darkmatter annihilation in the Sun with the IceCube neutrino telescope. Gravitationally trapped dark matter in the Sun’s core can annihilate into Standard Model particles making the Sun a source of GeV neutrinos. IceCube is able to detect neutrinos with energies>100GeVwhile its low-energy infill array DeepCore extends this to >10GeV. This analysis uses data gathered in the austral winters between May 2011 and May 2014, corresponding to 532 days of livetime when the Sun, being below the horizon, is a source of up-going neutrino events, easiest to discriminate against the dominant background …

First Search For Dark Matter Annihilations In The Earth With The Icecube Detector, Karen Andeen, Icecube Collaboration

Physics Faculty Research and Publications

We present the results of the first IceCube search for dark matter annihilation in the center of the Earth. Weakly interacting massive particles (WIMPs), candidates for dark matter, can scatter off nuclei inside the Earth and fall below its escape velocity. Over time the captured WIMPs will be accumulated and may eventually self-annihilate. Among the annihilation products only neutrinos can escape from the center of the Earth. Large-scale neutrino telescopes, such as the cubic kilometer IceCube Neutrino Observatory located at the South Pole, can be used to search for such neutrino fluxes. Data from 327 days of detector livetime during …

Search For Associated Production Of Dark Matter With A Higgs Boson Decaying To B B ¯ Or Γγ At √S=13 Tev, A. M. S, Marc M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, Daniel Noonan, Tuhin S. Roy, F. Yumiceva, The Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A search for dark matter is performed looking for events with large missing transverse momentum and a Higgs boson decaying either to a pair of bottom quarks or to a pair of photons. The data from proton-proton collisions at a center-of-mass energy of 13 TeV, collected in 2015 with the CMS detector at the LHC, correspond to an integrated luminosity of 2.3 fb−1. Results are interpreted in the context of a Z′-two-Higgs-doublet model, where the gauge symmetry of the standard model is extended by a U(1)Z ′ group, with a new massive Z′ gauge boson, and the Higgs sector is …

Search For Dark Matter In Proton-Proton Collisions At 8 Tev With Missing Transverse Momentum And Vector Boson Tagged Jets, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A search is presented for an excess of events with large missing transverse momentum in association with at least one highly energetic jet, in a data sample of proton-proton collisions at a centre-of-mass energy of 8 TeV. The data correspond to an integrated luminosity of 19.7 fb−1 collected by the CMS experiment at the LHC. The results are interpreted using a set of simplified models for the production of dark matter via a scalar, pseudoscalar, vector, or axial vector mediator. Additional sensitivity is achieved by tagging events consistent with the jets originating from a hadronically decaying vector boson. This search …

Examination Of Resonant Modes In Microwave Cavities, Sophia Schwalbe, Gianpaolo Carosi

Student Works

The Axion Dark Matter eXperiment (ADMX) looks to detect dark matter axion particles by using microwave cavities in a high magnetic eld to convert the axion's mass energy to a detectable photon. The photon frequency corresponds to the axion mass. Tuning elements in the cavities allow the resonant frequency to be changed but only certain modes couple to the axion. Interactions with additional resonant modes that do not couple to the axion cause unobservable regions in the frequency range. This research investigated new methods to move the additional resonant modes in order to observe these regions.

Finding The First Stars, Eli D. Mcarthur

Student Works

Minor perturbations resulting from a brief period of inflation at the time of the universe's birth seeded the growth of all structure in the universe. Using Enzo, a research code optimized for running cosmological simulations, we simulate the formation of the universe. We take into account the most current cosmological parameters and plot star formation rates of the universe for halos of varying mass from the beginning of time until today. By simulating star formation of the early universe, we verify that initially minuscule dark matter pockets resulting from inflationary perturbations attract more and more matter as the universe expands. …

Search For New Phenomena In Monophoton Final States In Proton-Proton Collisions At √S=Tev, M M. Baarmand, Marcus Hohlmann, H Kalakhety, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

Results are presented from a search for new physics in final states containing a photon and missing transverse momentum. The data correspond to an integrated luminosity of 19.6 fb-1 collected in proton-proton collisions at √s=TeV with the CMS experiment at the LHC. No deviation from the standard model predictions is observed for these final states. New, improved limits are set on dark matter production and on parameters of models with large extra dimensions. In particular, the first limits from the LHC on branon production are found and significantly extend previous limits from LEP and the Tevatron. An upper limit of …

A Search For Pair Production Of New Light Bosons Decaying Into Muons, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Mareskas-Palcek, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A search for the pair production of new light bosons, each decaying into a pair of muons, is performed with the CMS experiment at the LHC, using a dataset corresponding to an integrated luminosity of 20.7 fb-1 collected in proton-proton collisions at center-of-mass energy of √s=8 TeV. No excess is observed in the data relative to standard model background expectation and a model independent upper limit on the product of the cross section, branching fraction, and acceptance is derived. The results are compared with two benchmark models, the first one in the context of the next-to-minimal supersymmetric standard model, and …

Validation Of Argon From Underground Sources For Use In The Darkside-50 Detector, Thomas R. Alexander

Masters Theses

Liquid argon is an attractive target for dark matter searches due to its low cost and exemplary event discrimination. However, atmospherically derived argon contains the beta-emitter 39Ar which confounds the growth of dual-phase time projection chamber (TPC) style detectors to the ton-scale. The DarkSide Collaboration seeks to bypass this limitation by extracting argon from deep underground, from a location known to contain significantly less 39Ar than atmospherically derived argon. This thesis will summarize the e orts taken to produce the first batch of underground argon, focusing on the first operation of the underground argon in a dual-phase TPC to validate …

Predictions And Constraints Of Cosmological Correlators, Jayanth Tallakere Neelakanta

Dissertations - ALL

In this dissertation, we study the role of correlation functions in Cosmology. The study is bidirectional: We explore the constraints that correlation functions gathered from data impose on different theories; we also analyze the constraints that get imposed on correlation functions given symmetries of theories. For the former analysis, we use structure formation data like the CMB and matter power spectrum to set limits on the temperature of cold dark matter particles, basically only assuming that the particles were nonrelativistic when they decoupled and have interacted negligibly since. In another study, we use the same data to constrain how much …

Beyond Standard Model Physics Under The Ground And In The Sky, Bithika Jain

Dissertations - ALL

Cosmology and particle physics are in an exciting data-rich era, with several collider and astronomical searches underway. In this dissertation, we have explored some problems which are not addressed by the standard models of particle physics and cosmology. The implications of the Higgs discovery and lack of new physics results are far reaching. To better understand the nature of Higgs and its connections to electroweak symmetry breaking, we have performed a model independent study of spin-1 contributions in gauge extensions of Standard model. The null results of all low energy supersymmetric searches has lead to the development of Split SUSY …

Characterizing New Calibration Sources In Liquid Xenon Dark Matter Searches, Evan P. Bray, Rafael Lang, Sean Macmullin

The Summer Undergraduate Research Fellowship (SURF) Symposium

In order to use the XENON1T liquid xenon detector as a means for detecting dark matter, the response to nuclear and electronic recoils must be well calibrated. Electronic-recoil calibration of XENON1T will be done by using the noble gas radon-220 that emanates from a custom thorium-228 source to observe the electron recoils that its daughter elements induce in liquid xenon. A silicon PIN diode was constructed to ensure that the Th228 source does not contaminate the system with the long-lived isotopes Th228 (T1/2 of 1.9 y) or Radium-224 (T1/2 of 3.6 d). The PIN diode was fixed in a custom …

Beyond The Standard Model: Lhc Phenomenology, Cosmology From Post-Inflationary Sources, And Dark Matter Physics, Brian J. Vlcek

Theses and Dissertations

It is the goal of this dissertation to demonstrate that beyond the standard model, certain theories exist which solve conflicts between observation and theory -- conflicts such as massive neutrinos, dark matter, unstable Higgs vacuum, and recent Planck observations of excess relativistic degrees of freedom in the early universe. Theories explored include a D-brane inspired construct of U(3) × Sp(1) × U(1) × U(1) extension of the standard model, in which we demonstrate several possible observables that may be detected at the LHC, and an ability to stabilize the Higgs mechanism. The extended model can also explain recent Planck data …