Fast Statistical Methods For The Global Qcd Analysis Of The Proton Structure,
2021
Southern Methodist University
Fast Statistical Methods For The Global Qcd Analysis Of The Proton Structure, Xiaoxian Jing
Physics Theses and Dissertations
Parton distribution functions (PDFs) quantify probabilities to find partons (quarks and gluons) in a hadron as a function of the fraction x of the hadron’s momentum carried by the parton at a given energy scale. PDFs play a critical role in precision tests of the Standard Model in Higgs boson production and other electroweak processes at the Large Hadron Collider (LHC), and in searches for physics beyond the Standard Model. PDFs are obtained by the global QCD analysis, which fits theoretical predictions to experimental measurements. PDF fitting and post-analysis are computationally intensive. This dissertation discusses fast statistical methods for the …
Study Of The Geometric Structure Of Low-Atomic Copper Clusters Using Computer Simulation,
2021
Ferghana Polytechnic Institute
Study Of The Geometric Structure Of Low-Atomic Copper Clusters Using Computer Simulation, Nodirbek Ikromjonovich Ibrokhimov
Scientific-technical journal
In this work, we investigated the geometric structure of small neutral copper clusters with low energy using the MD (Molecular Dynamics) method. When calculating the processes of interatomic interaction, we used a potential EAM (Embedded-atom method). A computer model of Cun (n = 2-13) clusters has been created. The geometric shapes of the Cu2, Cu3, Cu4, Cu5, Cu6, Cu7, Cu8, Cu9, Cu10, Cu11, Cu12, and Cu13 clusters have been studied and the structural parameters (Cu-Cu bond …
Lorentz Violations And The Casimir Effect,
2021
California Polytechnic State University, San Luis Obispo
Lorentz Violations And The Casimir Effect, Samuel G. Christensen
Physics
The background and calculation for the corrections to the Casimir Energy stored on parallel conducting plates due to minimal violations of Lorentz invariance are presented as a test of the Standard Model. A direction-dependent photon dispersion relation using operators of dimension 4 and higher is used in the calculation of the spacetime anisotropy correction terms to the Casimir energy. The calculation includes discussion of Riemann zeta function regularization and its equivalence to Euler-Maclaurin sum-integral formulas in a Casimir effect calculation. The two plate geometry result is mapped onto a one plate and sphere geometry to cater to modern precision tests …
Space Charge Effects In Low Energy Magnetized Electron Beams,
2021
Old Dominion University
Space Charge Effects In Low Energy Magnetized Electron Beams, W. M. Sajini Anushika Kumari Wijethunga
Physics Theses & Dissertations
Magnetized electron cooling of the ion beam is one of the major approaches towards obtaining the required high luminosity in the proposed Electron-Ion Collider (EIC). To increase the cooling efficiency, a bunched electron beam with a high bunch charge and high repetition rate is required. However, these features can combine to enhance the collective interactions, such as the space charge effect. A magnetized electron beam was successfully generated at the Thomas Jefferson National Accelerator Facility (JLab) using a compact, 300 kV DC high voltage photo-gun with an inverted insulator geometry and bi-alkali antimonide photocathode. The beam magnetization was characterized using …
Acoustic Parameters As Discriminators Of Wall Events In Pico Dark Matter Search Data,
2021
Northeastern Illinois University
Acoustic Parameters As Discriminators Of Wall Events In Pico Dark Matter Search Data, Lucia Volkova
University Honors Program Senior Projects
Bubble chambers are one of several detector types that particle physicists use to search for the as-yet-undetected dark matter. The PICO collaboration – formed from the merger of the similar PICASSO and COUPP experiments – runs such a bubble detector using superheated fluorocarbons (with and without iodine). Bubbles that form along chamber walls exhibit different behavior than those which nucleate in the bulk of the target liquid due to shape distortions from the wall boundary; in previous analyses when searching for dark matter, these wall events have been cut from the data to control for the differing behavior using information …
Beyond The Standard Models Of Particle Physics And Cosmology,
2021
Syracuse University
Beyond The Standard Models Of Particle Physics And Cosmology, Gabriele Rigo
Dissertations - ALL
Despite their numerous successes both from the theoretical and experimental point of view, conceptual and observational evidence suggests the Standard Models of Particle Physics and Cosmology should be considered incomplete theories, reliable only within their well-defined regime of validity. This dissertation covers various possible extensions of those models from the theoretical, phenomenological and model-building perspective. The topics analyzed range from extra-dimensional approaches to the hierarchy problem, to the AdS/CFT description of perturbative anomaly inflow, and new probes of vacuum energy in neutron stars and gravitational waves.
Model Of Electromagnetic Waves In An Axion-Induced Parity Symmetry Violation,
2021
Macalester College
Model Of Electromagnetic Waves In An Axion-Induced Parity Symmetry Violation, Sarah Lipstone
Macalester Journal of Physics and Astronomy
Axion particles have been postulated to resolve the strong CP problem in Quantum chromodynamics. The axion field may double as the inflaton field that produces cosmic inflation. In this project, we use a combination of analytical and numerical analysis to study how axion-induced parity symmetry violation affects the dynamics of electromagnetic waves.
Detecting The Phi Meson With Clas12,
2021
University of Connecticut
Detecting The Phi Meson With Clas12, Paul Simmerling
Honors Scholar Theses
Analysis and detection of the phi(1020) vector meson from exclusive electroproduction decay into Kaons have been performed. Studying exclusive phi electroproduction is an ideal channel for quantifying the gluonic properties of the nucleon. This detection used the CEBAF Large Acceptance Spectrometer (CLAS12) at Thomas Jefferson National Accelerator Facility (JLab) with a 10.6 GeV longitudinally polarized electron beam and an unpolarized hydrogen target. Using the detected final state particles phase space, x_B, Q^2, W, and by developing specialized exclusivity cuts as well as several additional cuts, events containing the production of a phi(1020) meson were able to be extracted. Additionally, a …
Software Validation And Data Quality Monitoring Of The Klm Detector At Belle Ii.,
2021
University of Louisville
Software Validation And Data Quality Monitoring Of The Klm Detector At Belle Ii., Dustyn Hofer
College of Arts & Sciences Senior Theses
The Belle II Experiment at the SuperKEKB collider in Tsukuba, Japan is the latest of a new generation of B-factory experiments, designed to produce B meson particles in abundance. The aim of the Belle II experiment is to "discover new physics in the decay of the bottom quark (b), charm quark (c) and tau lepton (τ) and explore the dark sector." The SuperKEKB collider aims to produce instantaneous luminosities of upwards of 8 × 1035 cm−2 s−1, nearly an order of magnitude higher than previous B- factory experiments Belle and BABAR. Software packages, such as physics modules for the popular …
Curved Spacetime In The Causal Set Approach To Quantum Gravity,
2021
University of Mississippi
Curved Spacetime In The Causal Set Approach To Quantum Gravity, Ayush Dhital
Honors Theses
Causal Set theory is an approach to quantum gravity. In this approach, the spacetime continuum is assumed to be discrete rather than continuous. The discrete points in a causal set can be seen as a continuum spacetime if they can be embedded in a manifold such that the causal structure is preserved. In this regard, a manifold can be constructed by embedding a causal set preserving causal information between the neighboring points. In this thesis, some of the fundamental properties of causal sets are discussed and the curvature and dimension information of Minkowski, de Sitter, and Anti-de Sitter spaces is …
Study Of Neutral Hadron Production In A High Intensity Particle Physics Experiment.,
2021
University of Louisville
Study Of Neutral Hadron Production In A High Intensity Particle Physics Experiment., Jake W. Berg
Electronic Theses and Dissertations
In this dissertation I present independent measurements of the multiplicities, R, of π0 and η mesons produced in annihilation interactions of electrons and positrons at a center-of-mass energy of 10.54 GeV. Data were collected using the BaBar detector at the PEP-II storage rings located at the SLAC National Accelerator Laboratory in Menlo Park, California. Both mesons have a decay mode to two photons, which is used to identify them and measure their production per event. I find R(π0) = 2.8±0.3 per event and R(η) = 0.25±0.03 per event. I also present my contributions to …
Exploring Manifoldlike Causal Sets And Their Dimensions,
2021
University of Mississippi
Exploring Manifoldlike Causal Sets And Their Dimensions, Santosh Bhandari
Honors Theses
Causal Set Theory is an approach to quantum gravity that tries to replace the continuum spacetime structure of general relativity with the spacetime that has the property of discreteness and causality. From the standpoint of causal set theory, our spacetime is made up of discrete points that are causally related to one another. A causal set is said to be manifoldlike if it can be faithfully embedded in a Lorentzian manifold. In this thesis, some of the fundamental properties of causal sets are discussed. The first chapter is devoted to the historical background of quantum gravity with a discussion of …
A Search For New Physics In B(S) To Mu+Mu- Decays Using Multivariate Data Analysis, And Development Of Particle Detection Technology With Silicon Pixel Detectors,
2021
University of New Mexico
A Search For New Physics In B(S) To Mu+Mu- Decays Using Multivariate Data Analysis, And Development Of Particle Detection Technology With Silicon Pixel Detectors, Aidan Grummer
Physics & Astronomy ETDs
A suite of linked research projects is undertaken, combining a search for phenomena beyond the Standard Model of particle physics, development of new instruments for greater precision in detecting fundamental particles, and tracking and understanding the effect upon the detectors of the radiation that is an indelible element of their operating environment. Data recorded by the ATLAS Detector at CERN are employed in a search for evidence of undiscovered particles contributing to the rate of decays of B0 and B0s mesons to dimuon final states. New applications of machine learning techniques are implemented to separate this signal …
Exploring Qcd Factorization At Moderate Energy Scales,
2021
Old Dominion University
Exploring Qcd Factorization At Moderate Energy Scales, Eric Alan Moffat
Physics Theses & Dissertations
Asymptotic freedom in QCD facilitates the use of partonic degrees of freedom over short distances, but physical processes are sensitive to a wide range of scales. Thus, it is necessary in QCD calculations to utilize a factorization scheme to separate a process into perturbative and non-perturbative factors. This separation relies on an assumption that one energy scale is infinitely larger than the other scales involved in the process. However, much experimental research in areas such as nucleon structure and quark-hadron duality occur at more moderate energy scales where that basic assumption may not be true but perturbative calculations should still …
Copper Clusters: Study Of Geometric Structure Using Computer Simulation,
2021
Ferghana Polytechnic Institute
Copper Clusters: Study Of Geometric Structure Using Computer Simulation, Nodirbek Ikromjonovich Ibrokhimov
Karakalpak Scientific Journal
In this work, we investigated the geometric structure of small neutral copper clusters with low energy using the MD (Molecular Dynamics) method. When calculating the processes of interatomic interaction, we used a potential EAM (Embedded-atom method). A computer model of Cun (n = 2-13) clusters has been created. The geometric shapes of the Cu2, Cu3, Cu4, Cu5, Cu6, Cu7, Cu8, Cu9, Cu10, Cu11, Cu12, and Cu13 clusters have been studied and the structural parameters (Cu-Cu bond …
Lorentz Violation In Neutrino Interactions,
2021
California Polytechnic State University, San Luis Obispo
Lorentz Violation In Neutrino Interactions, Pranav Jayaram Seetharaman
Physics
Both the Standard Model of particle physics and General Relativity require Lorentz symmetry as a fundamental building block. In this paper, we learn about a framework called the Standard Model Extension that allows us to determine how physical phenomenon would change if we deviated from Lorentz invariance in the Standard Model and General Relativity. We use the Standard Model Extension to analyze a specific high-energy, astrophysical neutrino interaction that is only possible if Lorentz symmetry can be broken. The interaction we look at is the decay of a neutrino into an electron-positron pair, which is not possible in conventional physics. …
Extracting The Number Of Short Range Correlated Nucleon Pairs From Inclusive Electron Scattering Data,
2021
Old Dominion University
Extracting The Number Of Short Range Correlated Nucleon Pairs From Inclusive Electron Scattering Data, R. Weiss, A. W. Denniston, J. R. Pybus, O. Hen, E. Piasetzky, A. Schmidt, L. B. Weinstein, N. Barnea
Physics Faculty Publications
The extraction of the relative abundances of short-range correlated (SRC) nucleon pairs from inclusive electron scattering is studied using the generalized contact formalism (GCF) with several nuclear interaction models. GCF calculations can reproduce the observed scaling of the cross-section ratios for nuclei relative to deuterium at high xB and large Q2, a2 = (σA/A)/(σd/2). In the nonrelativistic instant-form formulation, the calculation is very sensitive to the model parameters and only reproduces the data using parameters that are inconsistent with ab initio many-body calculations. Using a light-cone GCF formulation significantly decreases this sensitivity …
Measurement Of The Cross Section Of Top Quark Pairs Produced In Association With A Photon In Lepton + Jets Events At √S = 13 Tev With Full Runii Cms Data,
2021
Wayne State University
Measurement Of The Cross Section Of Top Quark Pairs Produced In Association With A Photon In Lepton + Jets Events At √S = 13 Tev With Full Runii Cms Data, Nabin Poudyal
Wayne State University Dissertations
The inclusive production cross section of top quark pairs in association with a photon is measured in proton-proton collisions at the LHC with 13 TeV energy using the full RunII data collected by CMS in 2016, 2017, and 2018 with a total corresponding integrated luminosity of 137 fb −1 . The relative fraction of ttγ events normalized to inclusive tt production is measured. The cross section measurement provides important information about the electromagnetic coupling of the standard model top quark and is sensitive to physics beyond the standard model. The analysis is carried out in the in semileptonic decay channel …
Color Charge Correlations In The Proton At Nlo: Beyond Geometry Based Intuition,
2021
CUNY Bernard M Baruch College
Color Charge Correlations In The Proton At Nlo: Beyond Geometry Based Intuition, Adrian Dumitru, Heikki Mäntysaari, Risto Paatelainen
Publications and Research
Color charge correlators provide fundamental information about the proton structure. In this Letter, we evaluate numerically two-point color charge correlations in a proton on the light cone including the next-to-leading order corrections due to emission or exchange of a perturbative gluon. The non-perturbative valence quark structure of the proton is modelled in a way consistent with high-x proton structure data. Our results show that the correlator exhibits startlingly non-trivial behavior at large momentum transfer or central impact parameters, and that the color charge correlation depends not only on the impact parameter but also on the relative transverse momentum of …
Simulation Of An Ad 8099 Operational Amplifier For Use In The Readout Electronics Of Cosmic Ray Muon Detector,
2021
Kennesaw State University
Simulation Of An Ad 8099 Operational Amplifier For Use In The Readout Electronics Of Cosmic Ray Muon Detector, Gracyn Jewett, David Joffe
The Kennesaw Journal of Undergraduate Research
An AD 8099 Operational Amplifier was simulated in LT Spice in both one-stage and two-stage configurations for use in amplifying pulses coming from a cosmic-ray muon detector. The simulation showed that the AD 8099 is highly effective in amplifying pulses down to the 100 nV input range, with amplifications of 10-20 times in the case of the one-stage amplifier and 150-400 times in the case of the two-stage amplifier. The simulation also showed reasonable levels of pulse widening down to the 100 nV input range, with the pulse widening by no more than twice its original width in the one-stage …
