Elementary Particles and Fields and String Theory Commons^™

Neutrino Physics At A Research Reactor: Backgrounds And Analysis, Blaine Alexander Heffron

Doctoral Dissertations

The field of neutrino physics has a rich history and is currently the subject of much active research. The discovery of neutrino oscillations led to the conclusion that neutrinos have mass which was in contradiction to the Standard Model. Now researchers are investigating a number of open questions regarding neutrino properties such as their mass values or the existence of CP violation in the weak interaction. In order to answer these questions experimental and analytical techniques of neutrino detection are becoming more advanced, entering into an era of precision neutrino detection.

Nuclear reactors as a source of antineutrinos have played …

Measurement Of Neutrino-Induced Neutron Production In Lead, Brandon J. Becker

Doctoral Dissertations

The COHERENT Collaboration is an experimental effort to make the first measurement of coherent elastic neutrino-nucleus scattering (CE𝜈NS). The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory provides an intense, timed source of neutrinos from the decay of pions and muons produced during the spallation of mercury by 1 GeV protons generated in a particle accelerator. COHERENT seeks to make an unambiguous measurement by using a variety of low-threshold detectors capable of measuring the low-energy nuclear recoils resulting from CE𝜈NS interactions. This already challenging task is further complicated with the presence of backgrounds. Consequently, we must seek to reduce …

Electroweak Interactions And Fundamental Symmetries In Light Nuclei With Short-Range Effective Field Theories, Zichao Yang

Doctoral Dissertations

Effective field theories(EFTs) are powerful tools to study nuclear systems that display separation of scales. In this dissertation, we present halo EFT results for the $\beta$-delayed proton emission from $^{11}$Be, and pionless EFT results for three-nucleon systems. Halo nuclei are simply described by a tightly bound core and loosely bound valence nucleons. Using the halo EFT, we calculate the rate of the rare decay $^{11}$Be, which is a well-known halo nucleus, into $^{10}\text{Be} + p +e^- + \bar{\nu}_e$. We assume a shallow $1/2 ^+$ resonance in the $^{10}$Be$-p$ system with an energy consistent with a recent experiment by Ayyad {\it …

Towards Neutron Transformation Searches, Joshua L. Barrow

Doctoral Dissertations

To probe the origins of the baryon asymmetry, baryon number violation, the last unconfirmed Sakharov condition, must be definitively observed experimentally. Similarly, the nature of dark matter is currently unknown, and calls out for new candidates to be investigated. Each of these issues can be considered through the study of neutron transformations.

Some rare baryon number violating processes, such as neutron-antineutron transformations, are expected to probe baryogenesis. Here, I show progress on this discovery target through construction of more accurate Monte Carlo models, the design of future detectors, creation of more complete atmospheric neutrino background simulations, and use of automated …

Jet-Hadron Correlations Relative To The Event Plane Pb--Pb Collisions At The Lhc In Alice, Joel Anthony Mazer

Doctoral Dissertations

In relativistic heavy ion collisions at the Large Hadron Collider (LHC), a hot, dense and strongly interacting medium known as the Quark Gluon Plasma (QGP) is produced. Quarks and gluons from incoming nuclei collide to produce partons at high momenta early in the collisions. By fragmenting into collimated sprays of hadrons, these partons form 'jets'. Within the framework of perturbative Quantum Chromodynamics (pQCD), jet production is well understood in pp collisions. We can use jets measured in pp interactions as a baseline reference for comparing to heavy ion collision systems to detect and study jet quenching. The jet quenching mechanism …

Characterization Of Reactor Background Radiation At Hfir For The Prospect Experiment, Blaine Alexander Heffron

Masters Theses

This work describes an investigation of the background radiation present at the High Flux Isotope Reactor (HFIR) on behalf of the PROSPECT collaboration. The PROSPECT experiment is designed to make a precision measurement of the antineutrino spectrum at HFIR and search for sterile neutrinos. Temporal and spacial variation of neutron and gamma backgrounds at the experiment site for the PROSPECT detector are measured in order to determine if the reactor correlated radiation will contribute a significant background to the inverse beta decay signal. Knowledge of spacial background variation will also be used to inform the design of a local shield …

Open Heavy Flavor Measurement At Forward Angles For Cu+Cu Collisions At Center Of Mass Nn Collision Energy 200 Gev, Irakli Garishvili

Doctoral Dissertations

The main purpose of Relativistic Heavy Ion Collider (RHIC) program is to study the Quark-Gluon Plasma (QGP), a deconfined state of matter believed to be created in ultra-relativistic heavy ion collisions. Heavy quarks, expected to be produced during the earlier stages of heavy ion collisions, serve as an important probe of the QGP.‎

‎The following dissertation presents measurements of single muons resulting from the semileptonic decay of heavy flavor quarks in the rapidity range of $1.4 < \vert\eta\vert < 1.9$ for Cu+Cu nuclei collisions at $\sqrt{s_{NN}}=200$ GeV measured by the PHENIX experiment. Single muon spectra were measured for three different centrality classes (0 - 20 \% , 20 - 40 \%, 40 - 94 \%) within the $p_{T}$ range of 1.0 - 4.0 GeV/c.‎

‎To calculate single muon spectra, a full background estimate was statistically subtracted from inclusive spectra of muon candidate tracks reconstructed in the PHENIX muon …