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Recent Articles in Physics

Particle Physics In The Lhc Era, Don Bunk Syracuse University

Particle Physics In The Lhc Era, Don Bunk

Physics - Dissertations

During the past 100 years experimental particle physicists have collected an impressive amount of data. Theorists have also come to understand this data extremely well. It was in the first half of the 20th century the efforts of the early pioneers of quantum mechanics laid the ground work for this understanding: quantum field theory. Through the tireless efforts of researchers during the later half of the 20th century many ideas came together to form what we now call the Standard Model (SM) of particle physics. Finally, it was through the ideas of the renormalization group and effective field theory that ...


Computer Programming To Advance Gravitational Lensing, Alex Roche Bridgewater State University

Computer Programming To Advance Gravitational Lensing, Alex Roche

Undergraduate Review

The purpose of this research was to create a computer code that would numerically test a Poisson equation relating the mass distribution of a lens galaxy cluster to weak gravitational shear. Einstein’s theory of general relativity predicts that space-time is bent by massive objects, and in weak gravitational lensing, galaxy clusters act as lenses. The observable result is that galaxies far behind the gravitational lens will appear slightly more elliptical than they actually are. The ellipticity of the background galaxies is quantifiable and is directly related to the weak gravitational shear, and the shear is used to determine the ...


Transubstantiation And Quantum Physics: The Parallels Of Mystery In Religion And Science, Zachary Sexton Providence College

Transubstantiation And Quantum Physics: The Parallels Of Mystery In Religion And Science, Zachary Sexton

Spring 2013, Science and Religion

As the study of physics has progressed into the abstract realm of quanta, some have argued that the notion of transubstantiation is an unreasonable understanding of the Eucharist. However, when confronted with the uncertainty that modern physics presents, sharp parallels between this uncertainty and the metaphysical mysteries of transubstantiation. If it is reasonable to accept uncertainty in quantum physics, then it should be reasonable to accept the mysteries within the metaphysical world.


Quantum Programming In Python: Quantum 1d Simple Harmonic Oscillator And Quantum Mapping Gate, Matthew Hoff California Polytechnic State University

Quantum Programming In Python: Quantum 1d Simple Harmonic Oscillator And Quantum Mapping Gate, Matthew Hoff

Physics

A common problem when learning Quantum Mechanics is the complexity in the mathematical and physical concepts, which leads to difficulty in solving and understanding problems. Using programming languages like Python have become more and more prevalent in solving challenging physical systems. An open-source computer algebra system, SymPy, has been developed using Python to help solve these difficult systems. I have added code to the SymPy library for two different systems, a One-Dimensional Quantum Harmonic Oscillator and a Quantum Mapping Gate used in Quantum Computing.


Pt Magnetic Polarization On Y3Fe5O12 And Magnetotransport Characteristics, Y. M. Lu, Y. Choi, C. M. Ortega, Xuemei Cheng, J. W. Cai, S. Y. Huang, L. Sun, C. L. Chien Bryn Mawr College

Pt Magnetic Polarization On Y3Fe5O12 And Magnetotransport Characteristics, Y. M. Lu, Y. Choi, C. M. Ortega, Xuemei Cheng, J. W. Cai, S. Y. Huang, L. Sun, C. L. Chien

Physics Faculty Research and Scholarship

Thin Pt films on an yttrium iron garnet (YIG=Y3Fe5O12) show ferromagneticlike transport properties, which may impact the functionality of Pt in spin current detection, but do not provide direct quantitative information on the Pt magnetization. We report magnetic x-ray magnetic circular dichroism measurements of YIG/Pt(1.5  nm) showing an average Pt moment of 0.054  μB at 300 K and 0.076  μB at 20 K. This observation indicates strong proximity effects and induced magnetic ordering in Pt on magnetic insulators and their contribution to the spin-related measurements should not ...


Particle Dynamics And Resistivity Characteristics In Bifurcated Current Sheets, Tushar Andriyas Utah State University

Particle Dynamics And Resistivity Characteristics In Bifurcated Current Sheets, Tushar Andriyas

All Graduate Theses and Dissertations

Charged particle chaos and its collective effects in different magnetic geometries are investigated in a sequence of various numerical experiments. The fields generated by the particles as a result of interaction with the background electric and magnetic fields is not accounted for in the simulation. An X-line is first used to describe the geometry of the magnetotail prior to magnetic reconnection and a study of the behavior of charged particles is done from a microscopic viewpoint. Another important geometry in the magnetotail prior to substorm onset is Bifurcated Current Sheet. The same analysis is done for this configuration. The existence ...


A Numerical Algorithm For Simulating Two Species Plasma, Richard F. Datwyler Utah State University

A Numerical Algorithm For Simulating Two Species Plasma, Richard F. Datwyler

All Graduate Theses and Dissertations

An algorithm for modeling two species plasmas, which evolves the number density, flow velocity, and temperature equations coupled to Maxwell's electric and magnetic field equations, is discussed. Charge separation effects and the displacement current are retained. Mathematical derivations of normal modes in cold and hot plasmas, as represented by dispersion relations resulting from a linear analysis of the two fluid equations, are presented. In addition, numerical theory in relation to the ideas of geometry, temporal and spatial discretization, linearization of the fluid equations, and an expansion using finite elements is given. Numerical results generated by this algorithm compare favorably ...


An Event-By-Event Comparison Of Clustering Algorithms For Photon Detection In The Star Endcap Calorimeter, William J. Pochron Valparaiso University

An Event-By-Event Comparison Of Clustering Algorithms For Photon Detection In The Star Endcap Calorimeter, William J. Pochron

Celebration of Undergraduate Scholarship

The STAR detector at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory uses polarized proton collisions to determine the origin of the proton spin, using measurements such as neutral pion asymmetries. The Endcap Electromagnetic Calorimeter (EEMC) in the STAR detector is especially useful for detecting photons from π° decays at forward angles. This latter measurement is obtained from the Shower Maximum Detector (SMD) in the EEMC where narrow crossed scintillator strips measure the energy deposited in them and can be used to identify the location of the photon shower. The electromagnetic shower most often deposits energy in a ...


Generating A ‘Clean’ Pi0 Spectrum In Star, William J. Pochron Valparaiso University

Generating A ‘Clean’ Pi0 Spectrum In Star, William J. Pochron

Celebration of Undergraduate Scholarship

The STAR detector at Brookhaven National Laboratory’s Relativistic Heavy Ion Collider uses polarized proton collisions to investigate the origin of the proton spin, using measurements such as neutral pion (π0) asymmetries. STAR’s Endcap Electromagnetic Calorimeter (EEMC) is especially useful for detecting photons from π0 decays at forward-angle scattering from ≈15 to ≈40 degrees above the beam direction. We identify π0’s by constructing invariant mass spectra from these photons. Large background contributions are present in these spectra and distort the true value of the π0 invariant mass. By applying constraints (cuts) on parameters such as the opening angle ...


Testing The Klein-Nishina Model For Compton Scattering Of 0.662 Mev Photons With A Focus On Lower Scattering Angles, Joel Rogers Valparaiso University

Testing The Klein-Nishina Model For Compton Scattering Of 0.662 Mev Photons With A Focus On Lower Scattering Angles, Joel Rogers

Celebration of Undergraduate Scholarship

The Thomson and Klein-Nishina equations for obtaining the differential cross section by Compton scattering of photons from free electrons in aluminum will be tested using 0.662 MeV photons from a Cesium-137 source. A NaI detector will be used to count the number of photons scattering from the target as a function of the scattering angle. A previous experiment carried out by VU student Josh Vredevoogd showed good agreement with the Klein-Nishina theory for angles greater than 45 but discrepancies with angles less than 45 degrees. This experiment will concentrate on testing the Klein-Nishina theory at angles less than 45 ...


A Study Of Light Variability In Dying Stars, Hannah Rotter, Aaron Seider, Austin Bain Valparaiso University

A Study Of Light Variability In Dying Stars, Hannah Rotter, Aaron Seider, Austin Bain

Celebration of Undergraduate Scholarship

In this research project, we observed and analyzed the light variability in a class of dying stars that are in the stage between Red Giant and White Dwarf in the evolution of stars like the Sun. Our observations were carried out during the summer and fall of 2012 at the Valparaiso Observatory. Thirty-two of these objects were observed in total. We analyzed a subset of 18 of these and found that they all varied in visual brightness by 10-70 percent. Periods for the variability were found for 8 out of 18 objects, and they range from 27 to 125 days ...


Stability Of The Gains Of The Star Endcap Calorimeter From 2006 To 2011, Kayla Kutz Valparaiso University

Stability Of The Gains Of The Star Endcap Calorimeter From 2006 To 2011, Kayla Kutz

Celebration of Undergraduate Scholarship

The Solenoid Tracker at RHIC (STAR) experiment, based at Brookhaven National Laboratory's Relativistic Heavy Ion Collider (RHIC), uses polarized-proton collisions to investigate sea quark and gluon contributions to the fundamental proton property called “spin.” The STAR detector's Endcap Electromagnetic Calorimeter (EEMC) measures the energy of particles produced by those collisions using a lead-scintillator sampling calorimeter, consisting of several layers that include pre-shower, shower maximum, tower, and post-shower detectors. In these detectors, the energy gains, which convert a measured pulse into an energy deposition, have been determined using data taken from the years 2006, 2009, and 2011. Changes in ...


A Measurement Of The Hyperpolarizability Of Carbon Tetrachloride By Eshg At 614.5 Nm, Wesley Cheek Valparaiso University

A Measurement Of The Hyperpolarizability Of Carbon Tetrachloride By Eshg At 614.5 Nm, Wesley Cheek

Celebration of Undergraduate Scholarship

The second hyperpolarizability (γ) of carbon tetrachloride was measured by gas-phase electric-field-induced second-harmonic generation (ESHG). Periodic phase matching was used in order to enhance the ESHG by gases illuminated by a cw argon-ion laser operating at 514.5 nm. Using nitrogen as a reference gas, γCCl4 can be calculated by means of the ratio γCCl4/ γ N2 determined to be 18.3 ± 0.7.


Neutral Pion Background Analysis At Star, Adam Clark Valparaiso University

Neutral Pion Background Analysis At Star, Adam Clark

Celebration of Undergraduate Scholarship

The STAR detector at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory takes measurements of polarized proton collisions which can then be used to extract cross sections and spin asymmetries. The Endcap Electromagnetic Calorimeter (EEMC) in STAR allows measurements of electromagnetic particles in the forward direction, 1 < η < 2. The EEMC will be used to determine the neutral pion (π0) cross section and the double longitudinal spin asymmetry (ALL) which gives us information about the gluon contribution to the proton’s spin. The π0 cross section is an important supporting measurement to verify our signal reconstruction and the background characterization for the π0 asymmetry. In order to measure the π0 cross section and asymmetry, the backgrounds must be well understood (such as those from photon conversions and reconstruction errors where one photon reconstructs as two clusters). Efforts toward the π0 cross section and asymmetry measurements and, specifically, those to understand π0 backgrounds are discussed.


Dispersion Of Radon-222 Gas In Air, Erin Beckmeyer Valparaiso University

Dispersion Of Radon-222 Gas In Air, Erin Beckmeyer

Celebration of Undergraduate Scholarship

Radon-222 is a heavy radioactive gas with a half-life of 3.8 days, often found in basements and other enclosed, underground spaces. It is produced by decaying deposits of uranium-238, and presents a significant health risk to those who encounter it in their homes and places of work. The only gas in the uranium decay chain, radon atoms work their way through layers of soil, usually to dissipate harmlessly into the atmosphere. In buildings, however, the gas accumulates and causes dangerous environmental radiation. Much work has been done to measure the transmission of the gas through water and solid materials ...


Minimizing Travel Time Through Multiple Media With Various Borders, Tonja Miick Western Kentucky University

Minimizing Travel Time Through Multiple Media With Various Borders, Tonja Miick

Masters Theses & Specialist Projects

This thesis consists of two main chapters along with an introduction and
conclusion. In the introduction, we address the inspiration for the thesis, which
originates in a common calculus problem wherein travel time is minimized across two media separated by a single, straight boundary line. We then discuss the correlation of this problem with physics via Snells Law. The first core chapter takes this idea and develops it to include the concept of two media with a circular border. To make the problem easier to discuss, we talk about it in terms of running and swimming speeds. We first address ...


Unraveling The Structure Of 13Be, H Terry Fortune University of Pennsylvania

Unraveling The Structure Of 13Be, H Terry Fortune

Department of Physics Papers

Using a simple model for low-lying positive-parity resonances in 13Be as 10Be x (sd)3 and 12Be1p x (sd), I find that the lowest 5/2+ state is predominantly (sd)3. I give predictions for several additional states.


Continuum Three-Body Decays Of 9Be(5/2−), H Terry Fortune, R. Sherr University of Pennsylvania

Continuum Three-Body Decays Of 9Be(5/2−), H Terry Fortune, R. Sherr

Department of Physics Papers

We describe and discuss various three-body decay mechanisms for 9Be(5/2). We find that its decay to n+ 8Be(2+) is a small fraction of the total decay.


Excited States Of 19Mg, H Terry Fortune, R. Sherr University of Pennsylvania

Excited States Of 19Mg, H Terry Fortune, R. Sherr

Department of Physics Papers

We have calculated energies of the first two excited states of 19Mg by using a model that was previously successful for the ground state. Computed excitation energies are 1.12 and 1.54 MeV for (3/2) and (5/2), respectively—somewhat in disagreement with values of 1.38 and 2.14 MeV from a recent experiment.


Mass Of 18Mg(G.S.), H Terry Fortune, R. Sherr University of Pennsylvania

Mass Of 18Mg(G.S.), H Terry Fortune, R. Sherr

Department of Physics Papers

We use a potential model, together with spectroscopic factors from a combination of weak coupling and a shell-model calculation, to compute the mass of the ground state of 18Mg, considered as a mirror of 18C. The result is E2p=3.87(10)MeV.