Small-X Qcd Calculations With A Biased Ensemble, 2020 The Graduate Center, City University of New York

#### Small-X Qcd Calculations With A Biased Ensemble, Gary Kapilevich

*All Dissertations, Theses, and Capstone Projects*

In this dissertation, I will argue that we can study functional fluctuations in unintegrated gluon distributions, in the MV model as well as JIMWLK, using reweighting techniques, which will allow me to calculate QCD observables with "biased ensembles". This technique will enable me to study rare functional configurations of the gluon distributions, that might have been selected for in, for example, the centrality criteria used by the ATLAS and ALICE collaborations. After a review of these techniques, as well as a review of QCD physics at high energy in general, I will use biased ensembles to compute observables in two ...

Calculating Centrality Variables And Geometric Quantities Associated With High Energy Pb+Pb And Au+Au Collisions Using A Monte Carlo Glauber Model, 2020 Macalester College

#### Calculating Centrality Variables And Geometric Quantities Associated With High Energy Pb+Pb And Au+Au Collisions Using A Monte Carlo Glauber Model, Anya Wolterman

*Macalester Journal of Physics and Astronomy*

The Glauber model provides insight into the initial state of nuclear collisions by treating them in terms of the interactions between their constituent nucleons, in accordance with theories about the scattering of composite particles. These phenomenological techniques are commonly used to determine various geometric quantities associated with such complex, femtoscopic many-body systems. The Monte Carlo Glauber approach uses a random impact parameter and measured nuclear densities to investigate quantifiable properties like particle multiplicity and average geometric eccentricity for heavy ion collisions. The former involves incorporating a particle production model to plot the total transverse energy or the number of particles ...

Measurements Of Fast Alpha Decays In The 100sn Region, 2020 University of Tennessee, Knoxville

#### Measurements Of Fast Alpha Decays In The 100sn Region, Ian Connor Cox

*Chancellor’s Honors Program Projects*

No abstract provided.

Studies In Seop Hyperpolarized 3he: Measuring Ko And The Spatial Dependence Of Alkali Polarization, 2020 William & Mary

#### Studies In Seop Hyperpolarized 3he: Measuring Ko And The Spatial Dependence Of Alkali Polarization, Michael Cairo

*Undergraduate Honors Theses*

^{3}He is an isotope of helium whose nucleus is composed of two protons and one neutron. The proportion of atoms whose spins are pointed along the same direction in a volume of ^{3}He gas is known as the polarization. This study entails two experiments in the field of ^{3}He polarimetry concerned with measuring the polarization of a ^{3}He cell and reducing the uncertainty associated with it. ^{3}He cells are full of gaseous ^{3}He, along with alkali metal vapors, K and Rb in our case. The polarization of a ^{3}He cell can be measured ...

396— Radioactive Decay Calibrations Of Rics Using 41 Ar, 2020 SUNY Geneseo

#### 396— Radioactive Decay Calibrations Of Rics Using 41 Ar, Emily Vanderbilt, Nicole Gindling

*GREAT Day*

The short-lived isotope-counting system (SLIC) being built for the OMEGA laser facility at LLE requires gaseous radioisotopes for calibration purposes. Using a Plutonium-Beryllium (Pu-Be) source at SUNY Geneseo, 41Ar was made by capturing thermal neutrons via the 40Ar(n,gamma) reaction. Once activated, 41Ar beta decays, producing an electron with endpoint energy of 1.198 MeV. The daughter product is found to be the second excited state of 41K 99.1% of the time. This decays to the ground state and emits a 1.293 MeV gamma ray. To accurately measure the beta activity of 41Ar, the Gamma-X system at ...

293— Moly - Monitoring Oxygen Levels In Ntof Scintillators Using Cosmic Ray Muons, 2020 SUNY Geneseo

#### 293— Moly - Monitoring Oxygen Levels In Ntof Scintillators Using Cosmic Ray Muons, Sean King, Matthew Signor

*GREAT Day*

High Energy Density Physics and Inertial Confinement Fusion facilities employ nTOF methods to measure neutron energies. Laser induced fusion facilities use the beam pulse as a start signal and Xylene scintillators as the stop signal to obtain the time of flight. To improve timing performance, the scintillator liquid is quenched with oxygen reducing the light production. However, oxygen reacts with the scintillator liquid causing the detector photo flash decay time to increase that reduces the energy resolution of the detector. An in-situ monitoring system which uses cosmic ray muons to determine the oxygen concentration, is being developed at SUNY Geneseo ...

Development Of Convolutional Neural Nets For Κ/Π Differentiation At The Gluex Experiment, 2020 William & Mary

#### Development Of Convolutional Neural Nets For Κ/Π Differentiation At The Gluex Experiment, Matthew Mceneaney

*Undergraduate Honors Theses*

Lattice Quantum Chromodynamics (QCD) calculations predict a whole spectrum of exotic hybrid mesons thought to arise from gluonic excitation between a quark and antiquark. A systematic survey of strange and non-strange decay modes would be necessary to confirm this, and in particular studying decays to kaonic final states could confirm initial lattice QCD predictions. The GlueX experiment at Jefferson Lab studies the non-perturbative regime of the strong interaction and searches for hybrid mesons through light-quark meson spectroscopy; thus, kaon identification is critical for the GlueX experiment. Currently, the GlueX DIRC (Detection of Internally Reflected Cherenkov light) detectors provide clear kaon ...

Heavy Quark Expansion For Heavy-Light Light-Cone Operators, 2020 Old Dominion University

#### Heavy Quark Expansion For Heavy-Light Light-Cone Operators, Shuai Zhao

*Physics Faculty Publications*

We generalize the celebrated heavy quark expansion to nonlocal QCD operators. By taking nonlocal heavy-light current on the light-cone as an example, we confirm that the collinear singularities are common between QCD operator and the corresponding operator in heavy quark effective theory (HQET), at the leading power of 1/*M* expansion. Based on a perturbative calculation in operator form at one-loop level, a factorization formula linking QCD and HQET operators is investigated and the matching coefficient is determined. The matching between QCD and HQET light-cone distribution amplitudes (LCDAs) as well as other momentum distributions of hadron can be derived as ...

Data Acquisition And Analysis For Helicity-Correlated Asymmetries In Prex-Ii, 2020 William & Mary

#### Data Acquisition And Analysis For Helicity-Correlated Asymmetries In Prex-Ii, Quinn Campagna

*Undergraduate Honors Theses*

The goal of PREx-II is to measure the radius of the neutron distribution in the nucleus of ^{208}Pb to a precision of +/-1%, the original proposed goal of PREx-I. This is done by scattering polarized electrons off of a lead target, taking advantage of the parity-violating nature of the weak interaction. The difference in the scattering cross section for each helicity state allows us to extract the neutron radius of the nucleus. There can, however, be helicity-correlated beam asymmetries that are not related to the weak interaction. In order to extract these errors, we periodically modulate the beam energy ...

Author Correction: Closing The Nuclear Fuel Cycle With A Simplified Minor Actinide Lanthanide Separation Process (Alsep) And Additive Manufacturing, 2020 University of Nevada, Las Vegas

#### Author Correction: Closing The Nuclear Fuel Cycle With A Simplified Minor Actinide Lanthanide Separation Process (Alsep) And Additive Manufacturing, Artem V. Gelis, Peter Kozak, Andrew T. Breshears, M. Alex Brown, Cari Launiere, Emily L. Campbell, Gabriel B. Hall, Tatiana G. Levitskaia, Vanessa E. Holfeltz, Gregg J. Lumetta

*Chemistry and Biochemistry Faculty Publications*

No abstract provided.

Stellar Nucleosynthesis: Direct Measurement Of The Neutron-Capture Cross Sections Of Stable Germanium Isotopes And Design Of A Next Generation Ion Trap For The Study Of Beta-Delayed Neutron Emission, 2020 Louisiana State University and Agricultural and Mechanical College

#### Stellar Nucleosynthesis: Direct Measurement Of The Neutron-Capture Cross Sections Of Stable Germanium Isotopes And Design Of A Next Generation Ion Trap For The Study Of Beta-Delayed Neutron Emission, Alexander Laminack

*LSU Doctoral Dissertations*

Knowledge of stellar nuclear reaction rates is critical to understanding the cosmic origins of the abundances of elements. In order to determine these reaction rates, accurate measurements of nuclear cross sections are needed. This thesis presents the results of an experiment to directly measure the neutron capture cross sections of 70-Ge, 72-Ge, 74-Ge, and 76-Ge. These measurements were performed at the Los Alamos Neutron Science CEnter (LANSCE) using the Detector for Advanced Neutron Capture Experiments (DANCE). This is the first direct measurement for many of these isotopes across the neutron energy spectrum of 10 eV to 1 MeV using the ...

Study Of Cell Charging Effects For The Neutron Electric Dipole Moment Experiment At Oak Ridge National Laboratory, 2020 University of Kentucky

#### Study Of Cell Charging Effects For The Neutron Electric Dipole Moment Experiment At Oak Ridge National Laboratory, Mark Broering

*Theses and Dissertations--Physics and Astronomy*

The neutron electric dipole moment (nEDM) collaboration at the Spallation Neutron Source plans to use ultra-cold neutrons in superfluid helium to improve the nEDM limit by about two orders of magnitude. In this apparatus, neutrons are stored in poly(methyl methacrylate), PMMA, cells located in a strong, stable electric field. This electric field is produced by high voltage electrodes located outside of the neutron cells. Several sources generate charged particles inside the neutron cells. The electric field pulls these charges farther apart, attracting each to the oppositely charged electrode. As the charges build up on the cells walls, they create ...

Neutron Valence Structure From Nuclear Deep Inelastic Scattering, 2020 Old Dominion University

#### Neutron Valence Structure From Nuclear Deep Inelastic Scattering, E. P. Segarra, A. Schmidt, T. Kutz, D. W. Higinbotham, E. Piasetzky, M. Strikman, L. B. Weinstein, O. Hen

*Physics Faculty Publications*

Mechanisms of spin-flavor SU(6) symmetry breaking in quantum chromodynamics (QCD) are studied via an extraction of the free neutron structure function from a global analysis of deep inelastic scattering (DIS) data on the proton and on nuclei from A = 2 (deuterium) to 208 (lead). Modification of the structure function of nucleons bound in atomic nuclei (known as the EMC effect) are consistently accounted for within the framework of a universal modification of nucleons in short-range correlated (SRC) pairs. Our extracted neutron-to-proton structure function ratio F^{n}_{2}/F^{p}_{2} becomes constant for *x*_{B }≥ 0.6, equaling 0 ...

Decreasing Uncertainty In Nuclear Magnetic Resonance Measurements Through The Application Of Pappus Chains, 2020 University of New Hampshire

#### Decreasing Uncertainty In Nuclear Magnetic Resonance Measurements Through The Application Of Pappus Chains, Ryan Williams

*Honors Theses and Capstones*

To make further advancements in nuclear polarization, the Dynamic Nuclear Polarization Group at the University of New Hampshire requires an accurate measurement of the polarization of their materials. Through a non-traditional method of data analysis, the uncertainty in this polarization measurement via Nuclear Magnetic Resonance (NMR) was reduced. To extract the polarization, we measure an NMR signal through the real impedance of our circuitry, whose area is proportional to the polarization. However, our signal size depends on how in-tune our circuitry is with a specific frequency, with the signal growing smaller the less in-tune it becomes. A new method of ...

Effects Of Energy Resolution And Bin Size On The Measurements Of Nuclear Neutron Distributions Using Coherent Elastic Neutrino-Nucleus Scattering, 2020 Colby College

#### Effects Of Energy Resolution And Bin Size On The Measurements Of Nuclear Neutron Distributions Using Coherent Elastic Neutrino-Nucleus Scattering, Hongyong Zhang

*Honors Theses*

Coherent elastic neutrino-nucleus scattering is a process that involves the neutral-current scattering of a neutrino with an entire nucleus, which probes more bulk properties of the nucleus. Using the Taylor expansion of the form factors and calculation of effective moments that sums over isotopes, we successfully simulate the events for coherent elastic neutrino-nucleus scattering for detectors using Ar and Ge and demonstrate that coherent elastic neutrino-nucleus scattering can determine both the second moment and the fourth moment. Running the Monte Carlo simulation using a detector filled with 10 tonnes of natural germanium, a neutrino flux of 3*10^7 neutrinos ...

Investigation Of Isomer Ratios In The Reactions (Γ, N) And (N, 2N) On Nuclei 76Ge And 82Se, 2019 National University of Uzbekistan

#### Investigation Of Isomer Ratios In The Reactions (Γ, N) And (N, 2N) On Nuclei 76Ge And 82Se, Satimbay Palvanov, Turgunali Akhmadzhanov

*Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences*

The method of the induced activity measured the isomeric yield ratios and cross-sections ratios of reactions (γ, *n*) and (*n*, 2*n*) on nuclei ^{76}Ge and ^{82}Se. Samples of natural have been irradiated in the bremsstrahlung beam of the betatron SB-50 of National University of Uzbekistan in the energy range of 10-35 MeV with energy step of 1 MeV. For 14 MeV neutron irradiation, we used the NG-150 neutron generator of Institute of Nuclear Physics. The gamma spectra reactions products were measured with a spectroscopic system consisting of HPGe detector CANBERRA with energy resolution of 1.8 keV ...

Parton Distribution Functions From Loffe Time Pseudo-Distributions, 2019 Old Dominion University

#### Parton Distribution Functions From Loffe Time Pseudo-Distributions, Bálint Joó, Joseph Karpie, Kostas Orginos, Anatoly V. Radyushkin, David Richards, Savvas Zafeiropoulos

*Physics Faculty Publications*

In this paper, we present a detailed study of the unpolarized nucleon parton distribution function (PDF) employing the approach of parton pseudo-distribution functions. We perform a systematic analysis using three lattice ensembles at two volumes, with lattice spacings a = 0.127 fm and a = 0.094 fm, for a pion mass of roughly 400 MeV. With two lattice spacings and two volumes, both continuum limit and infinite volume extrapolation systematic errors of the PDF are considered. In addition to the x dependence of the PDF, we compute their first two moments and compare them with the pertinent phenomenological determinations.

Beam Asymmetry Σ For The Photoproduction Of Η And Ή Mesons At Eγ = 8.8gev, 2019 Old Dominion University

#### Beam Asymmetry Σ For The Photoproduction Of Η And Ή Mesons At Eγ = 8.8gev, S. Adhikari, A. Ali, M. J. Amaryan, A. Austregesilo, F. Barbosa, J. Barlow, A. Barnes, E. Barriga, R. Barsotti, T. D. Beattie, V. V. Berdnikov, T. Black, N. Wickramaarachchi, B. Zihlmann, The Gluex Collaboration

*Physics Faculty Publications*

We report on the measurement of the beam asymmetry Σ for the reactions →γp→pη and →γp→pη′ from the GlueX experiment using an 8.2–8.8-GeV linearly polarized tagged photon beam incident on a liquid hydrogen target in Hall D at Jefferson Laboratory. These measurements are made as a function of momentum transfer −t with significantly higher statistical precision than our earlier η measurements and are the first measurements of η′ in this energy range. We compare the results to theoretical predictions based on t-channel quasiparticle exchange. We also compare the ratio of Σ_{η} to Σ_{η ...}

Generalized Parton Distributions And Pseudodistributions, 2019 Old Dominion University

#### Generalized Parton Distributions And Pseudodistributions, Anatoly V. Radyushkin

*Physics Faculty Publications*

We derive one-loop matching relations for the Ioffe-time distributions (ITDs) related to the pion distribution amplitude (DA) and generalized parton distributions (GPDs). They are obtained from a universal expression for the one-loop correction in an operator form, and will be used in the ongoing lattice calculations of the pion DA and GPDs within the parton pseudodistributions approach.

Alpha Capture Reaction Rates For Nucleosynthesis Within An Ab Initio Framework, 2019 Louisiana State University and Agricultural and Mechanical College

#### Alpha Capture Reaction Rates For Nucleosynthesis Within An Ab Initio Framework, Alison Constance Dreyfuss

*LSU Doctoral Dissertations*

Clustering in nuclear systems has broad impacts on all phases of stellar burning, and plays a significant role in our understanding of nucleosynthesis, or how and where nuclei are produced in the universe. The role of alpha particles in particular is extremely important for nuclear astrophysics: ^{4}He was one of the earliest elements produced in the Big Bang, it is one of the most abundant elements in the universe, and helium burning -- in particular, the triple-alpha process -- is one of the most important ``engines'' in stars. To better understand nucleosynthesis and stellar burning, then, it is important to develop ...