Enhancing High-Order-Harmonic Generation By Time Delays Between Two-Color, Few-Cycle Pulses, 2017 University of Nebraska - Lincoln

#### Enhancing High-Order-Harmonic Generation By Time Delays Between Two-Color, Few-Cycle Pulses, Dian Peng, Liang-Wen Pi, M. V. Frolov, Anthony F. Starace

*Anthony F. Starace Publications*

Use of time delays in high-order-harmonic generation (HHG) driven by intense two-color, few-cycle pulses is investigated in order to determine means of optimizing HHG intensities and plateau cutoff energies. Based upon numerical solutions of the time-dependent Schrõdinger equation for the H atom as well as analytical analyses, we show that introducing a time delay between the two-color, few-cycle pulses can result in an enhancement of the intensity of the HHG spectrum by an order of magnitude (or more) at the cost of a reduction in the HHG plateau cutoff energy. Results for both positive and negative time delays as well ...

Data Collection And Analysis At The Atlas Detector, 2017 Yale University

#### Data Collection And Analysis At The Atlas Detector, Savannah Thais

*Yale Day of Data*

No abstract provided.

A Search For Double Beta Decay Of Xenon To Excited States Of Barium With Exo-200, 2017 University of Massachusetts - Amherst

#### A Search For Double Beta Decay Of Xenon To Excited States Of Barium With Exo-200, Sereres Johnston

*Doctoral Dissertations May 2014 - current*

This thesis presents searches for several modes of double beta decays of 136Xe to two low-lying excited levels of 136Ba. For each final level, both 2ν and 0ν double beta decay processes are considered. The data and general techniques developed by the EXO-200 collaboration are used, including a Machine Learning process to improve sensitivity in multivariate space. EXO-200 is an experimental program searching for 0νββ decay in a time projection chamber filled with 175 kg of liquid Xenon enriched to 80% 136Xe, functioning as both source and detector. Experimental searches of double beta decay with 136Xe and other isotopes are ...

Correction To Luminosity Measurement For The Pixel Luminosity Telescope At Cms, 2016 University of Tennessee, Knoxville

#### Correction To Luminosity Measurement For The Pixel Luminosity Telescope At Cms, Krishna Thapa

*Masters Theses*

The search for and detailed study of new particles and forces with the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) of CERN is fundamentally dependent on the precise measurement of the rate at which proton-proton collisions produce any particles, the so-called luminosity. Therefore, a new detector, the Pixel Luminosity Telescope (PLT), dedicated to measure the luminosity at high precision was added to the CMS experiment in 2015. It measures the inclusive charged particle production from each collision of proton bunches in the LHC. Additional charged particles which are observed by the instrument but produced from sources ...

Fluctuations In A Cosmology With A Spacelike Singularity And Their Gauge Theory Dual Description, 2016 McGill University

#### Fluctuations In A Cosmology With A Spacelike Singularity And Their Gauge Theory Dual Description, Robert H. Brandenberger, Elisa G.M. Ferreira, Ian A. Morrison, Yi-Fu Cai, Sumit R. Das, Yi Wang

*Ian Morrison*

We consider a time-dependent deformation of anti–de Sitter (AdS) space-time which contains a spacelike “singularity”—a spacelike region of high curvature. Making use of the AdS/CFT correspondence we can map the bulk dynamics onto the boundary. The boundary theory has a time dependent coupling constant which becomes small at times when the bulk space-time is highly curved. We investigate the propagation of small fluctuations of a test scalar field from early times before the bulk singularity to late times after the singularity. Under the assumption that the AdS/CFT correspondence extends to deformed AdS space-times, we can map ...

Probing Dark Matter-Neutrino Connection Via Indirect Detection Experiments, 2016 University of New Mexico

#### Probing Dark Matter-Neutrino Connection Via Indirect Detection Experiments, Bradley Knockel

*Physics & Astronomy ETDs*

Various evidence reveals that dark matter is a primary component of this universe. The amount of dark matter is known, but its identity is a mystery. To determine its properties, efforts to detect and produce dark matter are underway. Dark matter annihilations throughout the galaxy may produce photons, neutrinos, and cosmic rays. Neutrino and photon detectors may then indirectly detect dark matter by detecting these annihilation products. The annihilation rate, dark matter mass, and dark matter scattering rate off of matter affect the signals received at Earth. These signals can therefore probe the identity of dark matter, especially if dark ...

Rainich Conditions In (2+1)-Dimensional Gravity, 2016 Selected Works

#### Rainich Conditions In (2+1)-Dimensional Gravity, Dionisios Krongos, Charles G. Torre

*Charles G. Torre*

Fluctuations In A Cosmology With A Spacelike Singularity And Their Gauge Theory Dual Description, 2016 McGill University

#### Fluctuations In A Cosmology With A Spacelike Singularity And Their Gauge Theory Dual Description, Robert H. Brandenberger, Elisa G.M. Ferreira, Ian A. Morrison, Yi-Fu Cai, Sumit R. Das, Yi Wang

*Physics*

We consider a time-dependent deformation of anti–de Sitter (AdS) space-time which contains a spacelike “singularity”—a spacelike region of high curvature. Making use of the AdS/CFT correspondence we can map the bulk dynamics onto the boundary. The boundary theory has a time dependent coupling constant which becomes small at times when the bulk space-time is highly curved. We investigate the propagation of small fluctuations of a test scalar field from early times before the bulk singularity to late times after the singularity. Under the assumption that the AdS/CFT correspondence extends to deformed AdS space-times, we can map ...

Measurement And Modeling Of Cosmic Ray Exposure For Supercdms Dark Matter Detectors., 2016 University of Houston - Main

#### Measurement And Modeling Of Cosmic Ray Exposure For Supercdms Dark Matter Detectors., Kameron Mccall, John Orrell, Jared Yamaoka

*STAR (STEM Teacher and Researcher) Presentations*

Dark matter is an unknown type of matter that composes roughly 27% of the observable universe and, as cosmological structure models suggest, the earth should be passing through a “dark halo” of this unknown matter present in the Milky Way galaxy. As we pass through this halo, the Super Cryogenic Dark Matter Search (SuperCDMS) experiment aims to directly detect dark -matter particles. Though many dark matter particle candidates exist, SuperCDMS focuses on the detection of particles called WIMPS (weakly interacting massive particles) as predicted by super-symmetric theories beyond the standard model. Due to the high-sensitivity of the germanium detectors employed ...

Some 2-Categorical Aspects In Physics, 2016 The Graduate Center, City University of New York

#### Some 2-Categorical Aspects In Physics, Arthur Parzygnat

*All Graduate Works by Year: Dissertations, Theses, and Capstone Projects*

2-categories provide a useful transition point between ordinary category theory and infinity-category theory where one can perform concrete computations for applications in physics and at the same time provide rigorous formalism for mathematical structures appearing in physics. We survey three such broad instances. First, we describe two-dimensional algebra as a means of constructing non-abelian parallel transport along surfaces which can be used to describe strings charged under non-abelian gauge groups in string theory. Second, we formalize the notion of convex and cone categories, provide a preliminary categorical definition of entropy, and exhibit several examples. Thirdly, we provide a universal description ...

Imaging Population Transfer In Atoms With Ultrafast Electron Pulses, 2016 Purdue University

#### Imaging Population Transfer In Atoms With Ultrafast Electron Pulses, Hua-Chieh Shao, Anthony F. Starace

*Anthony F. Starace Publications*

We propose the use of ultrafast electron diffraction (UED) to image a controllable, laser-driven coherent electron population transfer in lithium atoms with currently available femtosecond electron pulses. Our simulations demonstrate the ability of ultrafast electrons to image such an electronic population transfer, thus validating UED as a direct means of investigating electron dynamics. Provided the incident electron pulses have sufficient temporal resolution, the diffraction images are shown to resolve also the relative phases of the target electronic wave functions.

A Study Of The Radiative Pion Capture Process As A Background To The Search For Muon To Electron Conversion With The Mu2e Experiment., 2016 University of Louisville

#### A Study Of The Radiative Pion Capture Process As A Background To The Search For Muon To Electron Conversion With The Mu2e Experiment., Jacob Colston

*Electronic Theses and Dissertations*

This thesis will introduce radiative pion capture (RPC), a process which can produce a fake signal in a search for the coherent conversion of a muon to an electron in the presence of a nucleus. There will be a brief introduction to standard model (SM) physics, as well as some more in-depth discussion of the relevant high energy physics at the Mu2e experiment. We will discuss charged lepton flavor violation (CLFV), as well as Supersymmetry, which predicts CLFV at higher intensities than the SM prediction. A description of the RPC process follows, including the external and internal conversions in pion ...

Introduction To Classical Field Theory, 2016 Department of Physics, Utah State University

#### Introduction To Classical Field Theory, Charles G. Torre

*All Complete Monographs*

This is an introduction to classical field theory. Topics treated include: Klein-Gordon field, electromagnetic field, scalar electrodynamics, Dirac field, Yang-Mills field, gravitational field, Noether theorems relating symmetries and conservation laws, spontaneous symmetry breaking, Lagrangian and Hamiltonian formalisms.

Multistart Spiral Electron Vortices In Ionization By Circularly Polarized Uv Pulses, 2016 University of Nebraska-Lincoln

#### Multistart Spiral Electron Vortices In Ionization By Circularly Polarized Uv Pulses, Jean Marcel Ngoko Djiokap, Alexei V. Meremianin, N. L. Manakov, S. X. Hu, L. B. Madsen, Anthony F. Starace

*Anthony F. Starace Publications*

*Multistart *spiral vortex patterns are predicted for the electron momentum distributions in the polarization plane following ionization of the helium atom by two time-delayed circularly polarized ultrashort laser pulses. For two ultraviolet (UV) pulses having the same frequency (such that two photons are required for ionization), single-color two-photon interferometry with corotating or counter-rotating time-delayed pulses is found to lead respectively to *zero*-start or *four*-start spiral vortex patterns in the ionized electron momentum distributions in the polarization plane. In contrast, two-color one-photon plus two-photon interferometry with time-delayed corotating or counter-rotating UV pulses is found to lead respectively to *one ...*

New Classical Solutions In Supergravity, 2016 Graduate Center, City University of New York

#### New Classical Solutions In Supergravity, Zhibai Zhang

*All Graduate Works by Year: Dissertations, Theses, and Capstone Projects*

In this Ph.D. thesis we construct three classes of new solutions to supergravity theories in various dimensions and study their properties. The first class is reduction ansatz of 10D and 11D supergravity on Ricci-flat and noncompact manifolds. These reductions are from a scaling limit of the famous spherical reductions, and can be solely supported by warp factors. The second class contains a large number of String/M theory solutions that have Lifshitz or Schrodinger scaling symmetry, obtained from marginally deforming the geometry of internal dimensions of previous solutions. We propose that these new solutions are dual to marginal deformations ...

Toward A Precision Measurement Of The Theta_13 Mixing Angle With The Double Chooz Detectors, 2016 University of Tennessee - Knoxville

#### Toward A Precision Measurement Of The Theta_13 Mixing Angle With The Double Chooz Detectors, Ben Thomas Rybolt

*Doctoral Dissertations*

Neutrinos are the most numerous and least understood particle in the universe. In the last few decades numerous experiments have been devoted to discovering their properties. The Double Chooz experiment was designed to make a precise measurement of θ_{13} [theta 13], the neutrino mixing parameter which describes flavor oscillations governing short baselines. To accomplish this measurement, two identical neutrino detectors have been deployed at a near and far baseline outside two commercial nuclear reactors. The neutrino flux and spectrum at the near and far detector sites will determine the disappearance of anti-neutrinos created inside the reactors.

I have contributed ...

Black Holes And Finite-Temperature Field Theory In Ads/Cft, 2016 College of William and Mary

#### Black Holes And Finite-Temperature Field Theory In Ads/Cft, Jackson Cross Olsen

*Undergraduate Honors Theses*

The Anti-de Sitter space/Conformal Field Theory (AdS/CFT) correspondence has motivated holographic models of physical phenomena at both zero and finite temperature. Zero-temperature results rely on one form of the correspondence, in which classical field theory calculations in a (usually modified) Anti-de Sitter space are said to be dual to calculations made for some quantum field theory at zero temperature. Finite-temperature calculations work similarly, except that the Anti-de Sitter space is taken to have a black hole horizon, and the correspondence is stated differently. In this work, we ask whether these two correspondences are in fact two distinct statements ...

Using Precise Measurements Of Muon G-2 To Constrain New Physics, 2016 Otterbein University

#### Using Precise Measurements Of Muon G-2 To Constrain New Physics, Evan M. Heintz

*Honors Thesis Projects*

We study the contributions to the anomalous magnetic moment of the muon from theories beyond the Standard Model, specifically supersymmetry. Results found at Brookhaven National Laboratory in 2001 during the E821 experiment indicate that current theories may not fully account for all of the interactions between the muon and fundamental gauge bosons. We re-derive Dirac's famous result of g=2. We then reproduce the one loop contributions from electroweak theory to the anomalous magnetic moment of the muon. We then use these calculations as a template for theories that go beyond the Standard Model. We show illustrative results for ...

Sensitivity Determination In The Chips Neutrino Detector, 2016 College of William and Mary

#### Sensitivity Determination In The Chips Neutrino Detector, Eve Adde Chase

*Undergraduate Honors Theses*

Through neutrino detection, we strive to provide constraints on various neutrino properties such as $\delta_{CP}$ and mass hierarchy. Neutrinos are difficult to detect and require large neutrino detectors with appropriate conditions to determine $\delta_{CP}$. While several neutrino experiments strive to constrain $\delta_{CP}$, additional detectors are necessary to further constrain these parameters. We present a computational model to determine detector sensitivity towards measuring unknown oscillation properties. This model focused on the CHIPS neutrino detector, a low-cost experiment designed to test detector technologies while providing to the wealth of information on neutrino properties. Sensitivity constraints are presented for $\Delta ...

Cebaf Upgrade Bunch Length Measurements, 2016 Old Dominion University

#### Cebaf Upgrade Bunch Length Measurements, Mahmoud Mohamad Ali Ahmad

*Physics Theses & Dissertations*

Many accelerators use short electron bunches and measuring the bunch length is important for efficient operations. CEBAF needs a suitable bunch length because bunches that are too long will result in beam interruption to the halls due to excessive energy spread and beam loss. In this work, bunch length is measured by invasive and non-invasive techniques at different beam energies. Two new measurement techniques have been commissioned; a harmonic cavity showed good results compared to expectations from simulation, and a real time interferometer is commissioned and first checkouts were performed. Three other techniques were used for measurements and comparison purposes ...