# Elementary Particles and Fields and String Theory Commons™

## All Articles in Elementary Particles and Fields and String Theory

990 full-text articles. Page 7 of 40.

Geometrization Of Hawking Radiation Via Ricci Flow, 2021 Winona State University

#### Geometrization Of Hawking Radiation Via Ricci Flow, Alexander Cassem

##### Ramaley Celebration

In 1982, Richard S. Hamilton formulated Ricci flow along manifolds of three dimensions of positive Ricci curvature as an attempt to resolve Poincaré’s Conjecture. However, it took until 2006 by Grigori Perelman to resolve the conjecture with Ricci flow. Since then, research in pure mathematics on Ricci Flow increased exponentially, and people began to apply it towards physics. For example, Ricci flow has been found to be the Renormalization Group flow of the bosonic string and sigma model. However, Ricci flow’s analogous counterpart being the heat equation, makes it appear to have more applications. For this reason, we have studied …

2021 University of Massachusetts Amherst

#### A Search For New Resonances Decaying Into A Weak Vector Boson And A Higgs Boson In Hadronic Final States With The Atlas Detector At The Large Hadron Collider, Zachary Alden Meadows

##### Doctoral Dissertations

A search for heavy resonances decaying to a $W$ or $Z$ boson and a Higgs boson in the final state is described. The search uses $139\ \mathrm{fb}^{-1}$ of proton-proton collision data at $\sqrt{s} = 13$ TeV collected by the ATLAS detector at the CERN Large Hadron Collider from 2015 to 2018. The results are presented in terms of constraints on a simplified model with a heavy vector triplet. Upper limits are set on the production cross-section times branching fraction for resonances decaying into a W/Z boson and a Higgs boson in the mass range between 1.2 to 5 TeV.

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 …

2021 University of Pennsylvania

#### Search For Trilepton Resonances From R-Parity Violating Chargino Decays In The B−L Mssm, George Ian Dyckes

##### Publicly Accessible Penn Dissertations

This dissertation presents a search for the electroweak pair-production of charginos and the associated production of charginos and neutralinos in the B−L Minimal Supersymmetric Standard Model with spontaneous R-parity violation. The chargino and neutralino each decay via R-parity violating couplings to a charged lepton or neutrino and a W, Z, or Higgs boson. This analysis searches for resonances in the trilepton invariant mass spectrum, targeting events with charginos decaying to three electrons or muons via a leptonically decaying Z boson. The dataset includes 139 1/fb of 13 TeV proton-proton collisions produced at the Large Hadron Collider and collected by the …

Temporal Coherent Control Of Resonant Two-Photon Double Ionization Of The Hydrogen Molecule Via Doubly Excited States, 2021 University of Nebraska-Lincoln

#### Temporal Coherent Control Of Resonant Two-Photon Double Ionization Of The Hydrogen Molecule Via Doubly Excited States, Jean Marcel Ngoko Djiokap, Anthony F. Starace

##### Anthony F. Starace Publications

We use time-delayed, counter-rotating, circularly polarized few-cycle attosecond nonoverlapping pulses to study the temporal coherent control of the resonant process of two-photon double ionization (TPDI) of hydrogen molecule via doubly excited states for pulse propagation direction along ˆk either parallel or perpendicular to the molecular axis ˆR. For ˆk ‖ ˆR and a pulse carrier frequency of 36 eV resonantly populating the Q2 1∏ + u (1) doubly excited state as well as other 1∏ + u doubly excited states, we find that the indirect ionization pathway through these doubly excited states changes the character of the kinematical vortex-shaped …

Search For Pair Production Of Third-Generation Scalar Leptoquarks Decaying Into A Top Quark And A Τ-Lepton In Pp Collisions At S√ = 13 Tev With The Atlas Detector, 2021 University of Aix-Marseille

#### Search For Pair Production Of Third-Generation Scalar Leptoquarks Decaying Into A Top Quark And A Τ-Lepton In Pp Collisions At S√ = 13 Tev With The Atlas Detector, Georges Aad, Braden Abbott, Dale C. Abbott, Adam Abed Abud, Kira Abeling, Dale K. Abhayasinghe, Syed H. Abidi, Ossama S. Abouzeid, Nicola L. Abraham, Halina Abramowicz

##### Physics Department Faculty Publication Series

A search for pair production of third-generation scalar leptoquarks decaying into a top quark and a tau-lepton is presented. The search is based on a dataset of pp collisions at root s = 13 TeV recorded with the ATLAS detector during Run 2 of the Large Hadron Collider, corresponding to an integrated luminosity of 139 fb(-1). Events are selected if they have one light lepton (electron or muon) and at least one hadronically decaying tau-lepton, or at least two light leptons. In addition, two or more jets, at least one of which must be identified as containing b-hadrons, are required. …

Measurements Of W+W−+ ≥ 1 Jet Production Cross-Sections In Pp Collisions At S√ = 13 Tev With The Atlas Detector, 2021 University of Aix-Marseille

#### Measurements Of W+W−+ ≥ 1 Jet Production Cross-Sections In Pp Collisions At S√ = 13 Tev With The Atlas Detector, Georges Aad, Braden Abbott, Dale C. Abbott, Adam Abed Abud, Kira Abeling, Deshan K. Abhayasinghe, Syed H. Abidi, Ossama S. Alexander Abouzeid, Nicola L. Abraham, Halina Abramowicz

##### Physics Department Faculty Publication Series

Fiducial and differential cross-section measurements of W+W- production in association with at least one hadronic jet are presented. These measurements are sensitive to the properties of electroweak-boson self-interactions and provide a test of perturbative quantum chromodynamics and the electroweak theory. The analysis is performed using proton-proton collision data collected at s = 13 TeV with the ATLAS experiment, corresponding to an integrated luminosity of 139 fb(-1). Events are selected with exactly one oppositely charged electron-muon pair and at least one hadronic jet with a transverse momentum of p(T)> 30 GeV and a pseudorapidity of |eta| < 4.5. After subtracting the background contributions and correcting for detector effects, the jet-inclusive W+W-+ >= 1 jet fiducial cross-section …

Muon Reconstruction And Identification Efficiency In Atlas Using The Full Run 2 Pp Collision Data Set At S√=13 Tev, 2021 University of Aix-Marseille

#### Muon Reconstruction And Identification Efficiency In Atlas Using The Full Run 2 Pp Collision Data Set At S√=13 Tev, Georges Aad, Braden Abbott, Dale C. Abbott, Adam Abed Abud, Kira Abeling, Deshan K. Abhayasinghe, Syed H. Abidi, Ossama S. Abouzeid, Nicola L. Abraham, Halina Abramowicz

##### Physics Department Faculty Publication Series

This article documents the muon reconstruction and identification efficiency obtained by the ATLAS experiment for 139 fb-1 of pp collision data at s=13 TeV collected between 2015 and 2018 during Run 2 of the LHC. The increased instantaneous luminosity delivered by the LHC over this period required a reoptimisation of the criteria for the identification of prompt muons. Improved and newly developed algorithms were deployed to preserve high muon identification efficiency with a low misidentification rate and good momentum resolution. The availability of large samples of Z -> mu mu and J/psi -> mu mu decays, and the minimisation of …

New Precise Spectroscopy Of The Hyperfine Structure In Muonium With A High-Intensity Pulsed Muon Beam, 2021 RIKEN

#### New Precise Spectroscopy Of The Hyperfine Structure In Muonium With A High-Intensity Pulsed Muon Beam, S. Kanda, Y. Fukao, Y. Ikedo, K. Ishida, M. Iwasaki, D. Kawall, N. Kawamura, K. M. Kojima, N. Kurosawa, Y. Matsuda

##### Physics Department Faculty Publication Series

A hydrogen-like atom consisting of a positive muon and an electron is known as muonium. It is a near-ideal two-body system for a precision test of bound-state theory and fundamental symmetries. The MuSEUM collaboration performed a new precision measurement of the muonium ground-state hyperfine structure at J-PARC using a high-intensity pulsed muon beam and a high-rate capable positron counter. The resonance of hyperfine transition was successfully observed at a near-zero magnetic field, and the muonium hyperfine structure interval of nu(HFS) = 4.463302(4) GHz was obtained with a relative precision of 0.9 ppm. The result was consistent with the previous ones …

Search For Charged Higgs Bosons Decaying Into A Top Quark And A Bottom Quark At √ S= 13 Tev With The Atlas Detector, 2021 University of Aix-Marseille

#### Search For Charged Higgs Bosons Decaying Into A Top Quark And A Bottom Quark At √ S= 13 Tev With The Atlas Detector, Georges Aad, Braden Abbott, Dale C. Abbott, Adam Abed Abud, Kira Abeling, Deshan K. Abhayasinghe, Syed H. Abidi, Ossama S. Alexander Abouzeid, Nicola L. Abraham, Halina Abramowicz

##### Physics Department Faculty Publication Series

A search for charged Higgs bosons decaying into a top quark and a bottom quark is presented. The data analysed correspond to 139 fb(-1) of proton-proton collisions at root s = 13TeV, recorded with the ATLAS detector at the LHC. The production of a heavy charged Higgs boson in association with a top quark and a bottom quark, pp -> tbH(+) -> tbtb, is explored in the H+ mass range from 200 to 2000 GeV using final states with jets and one electron or muon. Events are categorised according to the multiplicity of jets and b-tagged jets, and multivariate analysis …

A Real Triplet-Singlet Extended Standard Model: Dark Matter And Collider Phenomenology, 2021 University of Melbourne

#### A Real Triplet-Singlet Extended Standard Model: Dark Matter And Collider Phenomenology, Nicole F. Bell, Matthew J. Dolan, Leon S. Friedrich, Michael J. Ramsey-Musolf, Raymond R. Volkas

##### Physics Department Faculty Publication Series

We examine the collider and dark matter phenomenology of the Standard Model extended by a hypercharge-zero SU(2) triplet scalar and gauge singlet scalar. In particular, we study the scenario where the singlet and triplet are both charged under a single Z(2) symmetry. We find that such an extension is capable of generating the observed dark matter density, while also modifying the collider phenomenology such that the lower bound on the mass of the triplet is smaller than in minimal triplet scalar extensions to the Standard Model. A high triplet mass is in tension with the parameter space that leads to …

Measurements Of Differential Cross-Sections In Four-Lepton Events In 13 Tev Proton-Proton Collisions With The Atlas Detector, 2021 University of Aix-Marseille

#### Measurements Of Differential Cross-Sections In Four-Lepton Events In 13 Tev Proton-Proton Collisions With The Atlas Detector, Georges Aad, Braden Abbott, Dale C. Abbott, Adam Abed Abud, Kira Abeling, Deshan K. Abhayasinghe, Syed H. Abidi, Ossama S. Alexander Abouzeid, Nicola L. Abraham, Halina Abramowicz

##### Physics Department Faculty Publication Series

Measurements of four-lepton differential and integrated fiducial cross-sections in events with two same-flavour, opposite-charge electron or muon pairs are presented. The data correspond to 139 fb(-1) of root s = 13 TeV proton-proton collisions, collected by the ATLAS detector during Run 2 of the Large Hadron Collider (2015-2018). The final state has contributions from a number of interesting Standard Model processes that dominate in different four-lepton invariant mass regions, including single Z boson production, Higgs boson production and on-shell ZZ production, with a complex mix of interference terms, and possible contributions from physics beyond the Standard Model. The differential cross-sections …

Search For Doubly And Singly Charged Higgs Bosons Decaying Into Vector Bosons In Multi-Lepton Final States With The Atlas Detector Using Proton-Proton Collisions At √ S= 13 Tev, 2021 University of Aix-Marseille

#### Search For Doubly And Singly Charged Higgs Bosons Decaying Into Vector Bosons In Multi-Lepton Final States With The Atlas Detector Using Proton-Proton Collisions At √ S= 13 Tev, Georges Aad, Braden Abbott, Dale C. Abbott, Adam Abed Abud, Kira Abeling, Deshan K. Abhayasinghe, Syed H. Abidi, Ossama S. Alexander Abouzeid, Nicola L. Abraham, Halina Abramowicz

##### Physics Department Faculty Publication Series

A search for charged Higgs bosons decaying into (WW +/-)-W-+/- or W(+/-)Z bosons is performed, involving experimental signatures with two leptons of the same charge, or three or four leptons with a variety of charge combinations, missing transverse momentum and jets. A data sample of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded with the ATLAS detector at the Large Hadron Collider between 2015 and 2018 is used. The data correspond to a total integrated luminosity of 139 fb(-1). The search is guided by a type-II seesaw model that extends the scalar sector of the Standard Model with …

Resurgence Of The Qcd Adler Function, 2021 Ruder Bošković Institute

#### Resurgence Of The Qcd Adler Function, Alessio Maiezza, Juan Carlos Vasquez

##### Physics Department Faculty Publication Series

We study the QCD Adler function in the energy region approximate to 0.7 - 2.5 GeV, in which the non-perturbative effects become dominant. Our analysis is a renormalon-based evaluation using transseries within the resurgence of the Renormalization-Group-Equation and does not require the Operator-Product-Expansion. (C) 2021 The Author(s). Published by Elsevier B.V.

Measurements Of The Inclusive And Differential Production Cross Sections Of A Top-Quark-Antiquark Pair In Association With A Z Boson At S√=13 Tev With The Atlas Detector, 2021 University of Aix-Marseille

#### Measurements Of The Inclusive And Differential Production Cross Sections Of A Top-Quark-Antiquark Pair In Association With A Z Boson At S√=13 Tev With The Atlas Detector, Atlas Collaboration, Georges Aad, Braden Abbott, Dale C. Abbott, Adam Abed Abud, Kira Abeling, Deshan K. Abhayasinghe, Syed Haider Abidi, Ossama Sherif Alexander Abouzeid, Nicola L. Abraham

##### Physics Department Faculty Publication Series

Measurements of both the inclusive and differential production cross sections of a top-quark-antiquark pair in association with a Z boson (t (t) over barZ) are presented. The measurements are performed by targeting final states with three or four isolated leptons (electrons or muons) and are based on root s = 13 TeV proton-proton collision data with an integrated luminosity of 139 fb(-1), recorded from 2015 to 2018 with the ATLAS detector at the CERN Large Hadron Collider. The inclusive cross section is measured to be a sigma(t (t) over barZ)= 0.99 +/- 0.05 (stat.) +/- 0.08 (syst.) pb, in agreement …

An Online Radon Monitor For Low-Background Detector Assembly Facilities, 2021 Jagiellonian University, Poland

#### An Online Radon Monitor For Low-Background Detector Assembly Facilities, K. Pelczar, G. Zuzel, M. Wójcik, A. Pocar, An. Ianni

##### Physics Department Faculty Publication Series

Backgrounds from long-lived radon decay products are often problematic for low-energy neutrino and rareevent experiments. These isotopes, specifically 210Pb, 210Bi, and 210Po, easily plate out onto surfaces exposed to radonloaded air. The alpha emitter 210Po is particularly dangerous for detectors searching for weakly-interacting dark matter particles. Neutrons produced via (a, n) reactions in detector materials are, in some cases, a residual background that can limit the sensitivity of the experiment. An effective solution is to reduce the 222Rn activity in the air in contact with detector components during fabrication, assembly, commissioning, and operation. We present the design, construction, calibration procedures …

Neutron Cross Section Measurement In The Protodune-Sp Experiment, 2021 University of Pennsylvania

#### Neutron Cross Section Measurement In The Protodune-Sp Experiment, David Orlando Rivera

##### Publicly Accessible Penn Dissertations

Understanding the detector response to neutrons will be critical for performing neutrino oscillation analyses in the next-generation Deep Underground Neutrino Experiment (DUNE). The DUNE physics program is centered around measuring the neutrino flavor composition as a function of their energy both at the near and the far detector. Neutrinos in the DUNE beam will have energies ranging between 100 MeV and 10 GeV, which is significant, because individual neutrino energies will not be known beforehand and will have to be reconstructed. Neutrino interactions in DUNE will produce leptons and hadrons – including protons, pions, and neutrons. Neutrons can transport energy …