Fermion-Induced Electroweak Symmetry Non-Restoration Via Temperature-Dependent Masses,
2022
University of Nebraska-Lincoln
Fermion-Induced Electroweak Symmetry Non-Restoration Via Temperature-Dependent Masses, Yu Hang Ng
Theses, Dissertations, and Student Research: Department of Physics and Astronomy
Standard Model (SM) and many extensions of SM predict that the electroweak (EW) symmetry was restored in the early universe when the temperature was around 160 GeV. However, recent studies showed that the interactions between some new scalars and SU(2)_L Higgs doublet(s) can cause the EW symmetry to remain broken at temperatures well above the EW scale in certain renormalizable extensions of SM. In this study, we found that new fermions from renormalizable models can also induce this EW symmetry non-restoration effect, provided that they have the appropriate temperature-dependent masses. These masses can arise naturally from the interactions between the …
Search For A Dark Leptophilic Scalar Produced In Association With Taupair In Electron-Positron Annihilation At Center-Of-Mass Energies Near 10.58 Gev.,
2022
University of Louisville
Search For A Dark Leptophilic Scalar Produced In Association With Taupair In Electron-Positron Annihilation At Center-Of-Mass Energies Near 10.58 Gev., Diptaparna Biswas
Electronic Theses and Dissertations
Dark matter is believed to be a form of matter which seemingly accounts for approximately 85% of the matter in the universe and about 27% of its total mass–energy density. It doesn't participate in electromagnetic interaction, i.e. doesn't interact with light. Consequently, we cannot see it using optical or radio telescope and hence the name dark matter. However, it participates in gravitational interaction, and we hypothesize its existence based on a variety of astrophysical observations, including gravitational effects, that cannot be explained by the accepted theories of gravity unless we account for more matter than can be perceived through electromagnetic …
Measurement Of The Fiducial Cross Section For Vector-Boson-Fusion Production Of The Higgs Boson In The Ww Decay Channel With The Atlas Detector,
2022
University of Massachusetts Amherst
Measurement Of The Fiducial Cross Section For Vector-Boson-Fusion Production Of The Higgs Boson In The Ww Decay Channel With The Atlas Detector, Guy Rosin
Doctoral Dissertations
This doctoral thesis presents a measurement of the fiducial and differential cross section of vector boson fusion produced Higgs boson.The measurement is taken in the H → WW∗ → lνlν channel with 139 fb−1 of data. Proton-proton collisions from the Large Hadron Collider at √s = 13 TeV were recorded by the ATLAS detector. New analysis techniques using boosted decision trees with a statistical fit are introduced to accurately estimate backgrounds in the signal region. The fiducial cross section is measured to be 1.7 ± 0.42fb. The differential cross section was measured for 13 kinematic variables. No significant deviations …
Calibration Of The Lux-Zeplin Dual-Phase Xenon Time Projection Chamber With Internally Injected Radioisotopes,
2022
University of Massachusetts Amherst
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 …
General Covariance With Stacks And The Batalin-Vilkovisky Formalism,
2022
University of Massachusetts Amherst
General Covariance With Stacks And The Batalin-Vilkovisky Formalism, Filip Dul
Doctoral Dissertations
In this thesis we develop a formulation of general covariance, an essential property for many field theories on curved spacetimes, using the language of stacks and the Batalin-Vilkovisky formalism. We survey the theory of stacks, both from a global and formal perspective, and consider the key example in our work: the moduli stack of metrics modulo diffeomorphism. This is then coupled to the Batalin-Vilkovisky formalism–a formulation of field theory motivated by developments in derived geometry–to describe the associated equivariant observables of a theory and to recover and generalize results regarding current conservation.
What Is A Photon? Foundations Of Quantum Field Theory,
2022
Utah State University
What Is A Photon? Foundations Of Quantum Field Theory, Charles G. Torre
All Physics Faculty Publications
This is a brief, informal, and relatively low-level course on the foundations of quantum field theory. The prerequisites are undergraduate courses in quantum mechanics and electromagnetism.
Introduction To Classical Field Theory,
2022
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.
Partial Automation Of Data Analysis In A Z Prime Boson Search,
2022
Bellarmine University
Partial Automation Of Data Analysis In A Z Prime Boson Search, Ethan Colbert
Undergraduate Theses
Analysis of data from the ATLAS experiment at the LHC has been a research focus in the Department of Physics at Bellarmine University (BU). At BU, analysis has largely been focused on Z boson decays and searching for evidence of a Z’ (Z Prime) boson. The data are stored in the form of .xml files, with one file representing one collision event inside the ATLAS detector. Previous analyses have been conducted on an event-by-event basis, using the Hypatia software package. While this allows for high-quality visualization and effective event analysis, it is highly time-consuming. I propose and implement a piece …
A Performance Analysis Of The Belle Ii Detector,
2022
University of Mississippi
A Performance Analysis Of The Belle Ii Detector, John Stacy
Honors Theses
The Belle II experiment has recently (2018) started data taking at the SuperKEKB electron-positron collider in Tsukuba, Japan. Detector performance studies are necessary to understand early data and prepare for more complex analyses. This study of the proton detection efficiency of the Belle II detector compares real and simulated data to find discrepancies with the intention to provide useful information for detector and calibration experts to better gauge detector performance. It also attempts to improve the characterization of proton identification efficiency at low momenta, which performs poorly under the current fitting model. This helps analysts exploring final states that include …
Lifetime Measurement Of The Xi_C^+ Using Belle Ii Monte Carlo,
2022
University of Mississippi
Lifetime Measurement Of The Xi_C^+ Using Belle Ii Monte Carlo, Paul Gebeline
Honors Theses
This analysis uses simulated data from the Belle II experiment to measure the lifetime of the Xi_c^+ baryon. Three different decay modes are investigated to explore the feasibility and accuracy of such measurements at Belle II. The Xi_c^+ lifetime is measured using one of these modes after reducing backgrounds from sources other than the decay of interest. The final result is 464 +/- 15 fs, which is consistent with the expected result of 442 fs within uncertainty. This result shows that Belle II can make competitive measurements of particle properties and decays.
Monte Carlo Study Of Lepton Flavor Universality Violation In B Decays With Belle Ii Simulation,
2022
University of Mississippi
Monte Carlo Study Of Lepton Flavor Universality Violation In B Decays With Belle Ii Simulation, Sakul Mahat
Honors Theses
Belle II, the first super B-Factory experiment, is designed to make precise measurements of weak interaction parameters and search for New Physics beyond the Standard Model of particle physics. The Standard Model of particle physics is a theory that classifies all known elementary particles and describes three of the four known fundamental forces in the universe. Physics beyond the Standard Model that addresses the theoretical developments needed to explain the deficiencies in the Standard Model is often referred to as New Physics. One of the assumptions of the Standard Model is that the couplings of particles that mediate the weak …
Measurement Of Neutrino-Induced Neutron Production In Lead,
2022
University of Tennessee, Knoxville
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 …
Development Of A Prototype Electron Detector For Use In Ucna+,
2022
East Tennessee State University
Development Of A Prototype Electron Detector For Use In Ucna+, Richard Mcdonald
Undergraduate Honors Theses
The UCNA Experiment at the Los Alamos Neutron Science Center (LANSCE) uses an electron spectrometer to observe angular correlations between the neutron spin and the momenta of β particles emitted during the process of β decay. These angular correlations give rise to an asymmetry determined by the ratio of two coupling constants, gA and gV . Combined with neutron lifetime measurements, these observations probe physics beyond the standard model through unitarity tests of the Cabbibo-Kobayashi-Maskawa Matrix. UCNA’s current spectrometer uses a multi-wire proportional chamber and a plastic scintillator coupled to four photomultiplier tubes (PMTs) by 2 meters of light guides …
Studies Of Bonus12 Radial Gem Detector And Tcs Beam Spin Asymmetry In Clas12,
2022
Old Dominion University
Studies Of Bonus12 Radial Gem Detector And Tcs Beam Spin Asymmetry In Clas12, Jiwan Poudel
Physics Theses & Dissertations
The Barely Offshell Nucleon Structure (BONuS12) experiment adopted the concept of spectator tagging technique to study the nearly-free neutron structure function F2n in the CLAS12 of Jefferson Lab. A novel Radial Time Projection Chamber (RTPC) detector was built, tested and integrated into the CLAS12 system to detect a back-moving low momentum tagged proton in d(e, ep)X deep-inelastic scattering. It was a 40 cm long gaseous detector consisting of 3 layers of cylindrical GEM foils for the charge amplification, with the data readout directly from the surrounding padboard. The RTPC detected the recoiling spectator proton, in coincidence with …
Finite Dimensional Approximation And Pin(2)-Equivariant Property For Rarita-Schwinger-Seiberg-Witten Equations,
2022
University of Arkansas, Fayetteville
Finite Dimensional Approximation And Pin(2)-Equivariant Property For Rarita-Schwinger-Seiberg-Witten Equations, Minh Lam Nguyen
Graduate Theses and Dissertations
The Rarita-Schwinger operator Q was initially proposed in the 1941 paper by Rarita and Schwinger to study wave functions of particles of spin 3/2, and there is a vast amount of physics literature on its properties. Roughly speaking, 3/2−spinors are spinor-valued 1-forms that also happen to be in the kernel of the Clifford multiplication. Let X be a simply connected Riemannian spin 4−manifold. Associated to a fixed spin structure on X, we define a Seiberg-Witten-like system of non-linear PDEs using Q and the Hodge-Dirac operator d∗ + d+ after suitable gauge-fixing. The moduli space of solutions M contains (3/2-spinors, purely …
Einstein's Equations, Lagrangians For General Relativity, And Adm Formalism,
2022
University of Mary Washington
Einstein's Equations, Lagrangians For General Relativity, And Adm Formalism, Timothy Corbett
Student Research Submissions
Einstein’s equations describe the relation of spacetime curvature and present matter. We will consider the case of a Lorentzian manifold diffeomorphic to ℝ × Σ, where time t ∈ ℝ and the three-dimensional manifold Σ represents space. In a homogeneous and isotropic universe, the three-dimensional manifold Σ of the Lorentzian manifold has Riemann curvature tensor (3)R = KI, where K is a constant and I is the 3 × 3 identity matrix. Space is flat when K = 0, spherical when K is positive, and hyperbolic when K is negative. In this paper, we will show models agreeing with …
Using Z Boson Events To Study Parton-Medium Interactions In Pb-Pb Collisions,
2022
Yerevan Physics Institute
Using Z Boson Events To Study Parton-Medium Interactions In Pb-Pb Collisions, The Cms Collaboration, A. M. Sirunyan, A. Tumasyan, W. Adam, F. Ambrogi, T. Bergauer, Julie M. Hogan
Physics and Engineering Faculty Publications
The spectra measurements of charged hadrons produced in the shower of a parton originating in the same hard scattering with a leptonically decaying Z boson are reported in lead-lead nuclei (Pb-Pb) and proton-proton (pp) collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV. Both Pb-Pb and pp data sets are recorded by the CMS experiment at the LHC and correspond to an integrated luminosity of 1.7 nb-1 and 320 pb-1, respectively. Hadronic collision data with one reconstructed Z boson candidate with the transverse momentum pT>30 GeV/c are analyzed. The Z boson constrains the initial energy and direction of the …
Search For Wγ Resonances In Proton-Proton Collisions At S=13 Tev Using Hadronic Decays Of Lorentz-Boosted W Bosons,
2022
Yerevan Physics Institute
Search For Wγ Resonances In Proton-Proton Collisions At S=13 Tev Using Hadronic Decays Of Lorentz-Boosted W Bosons, The Cms Collaboration, A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, Julie M. Hogan
Physics and Engineering Faculty Publications
A search for Wγ resonances in the mass range between 0.7 and 6.0 TeV is presented. The W boson is reconstructed via its hadronic decays, with the final-state products forming a single large-radius jet, owing to a high Lorentz boost of the W boson. The search is based on proton-proton collision data at s=13 TeV, corresponding to an integrated luminosity of 137 fb−1, collected with the CMS detector at the LHC in 2016–2018. The Wγ mass spectrum is parameterized with a smoothly falling background function and examined for the presence of resonance-like signals. No significant excess above the predicted background …
Erratum: Search For Heavy Higgs Bosons Decaying To A Top Quark Pair In Proton-Proton Collisions At S = 13 Tev (Journal Of High Energy Physics, (2020), 2020, 4, (171), 10.1007/Jhep04(2020)171),
2022
Yerevan Physics Institute
Erratum: Search For Heavy Higgs Bosons Decaying To A Top Quark Pair In Proton-Proton Collisions At S = 13 Tev (Journal Of High Energy Physics, (2020), 2020, 4, (171), 10.1007/Jhep04(2020)171), The Cms Collaboration, A. M. Sirunyan, A. Tumasyan, W. Adam, F. Ambrogi, T. Bergauer, Julie M. Hogan
Physics and Engineering Faculty Publications
In figure 7 of the original publication, the label of the y axis should have been (Formula presented.)”. The corrected version is shown in figure 1. Accordingly, the text pointing to the figure should read “figure 7 shows scans of (Formula presented.) for this hypothesis, as a function of the coupling modifier gAtt-”.
Measurement Of W±Γ Differential Cross Sections In Proton-Proton Collisions At S =13 Tev And Effective Field Theory Constraints,
2022
Yerevan Physics Institute
Measurement Of W±Γ Differential Cross Sections In Proton-Proton Collisions At S =13 Tev And Effective Field Theory Constraints, The Cms Collaboration, A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, Julie M. Hogan
Physics and Engineering Faculty Publications
Differential cross section measurements of W±γ production in proton-proton collisions at s=13 TeV are presented. The data set used in this study was collected with the CMS detector at the CERN LHC in 2016-2018 with an integrated luminosity of 138 fb-1. Candidate events containing an electron or muon, a photon, and missing transverse momentum are selected. The measurements are compared with standard model predictions computed at next-to-leading and next-to-next-to-leading orders in perturbative quantum chromodynamics. Constraints on the presence of TeV-scale new physics affecting the WWγ vertex are determined within an effective field theory framework, focusing on the O3W operator. A …
