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Full-Text Articles in Physics
Neutral Pion Background Analysis At Star, Adam Clark
Neutral Pion Background Analysis At Star, Adam Clark
Symposium on Undergraduate Research and Creative Expression (SOURCE)
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.
An Event-By-Event Comparison Of Clustering Algorithms For Photon Detection In The Star Endcap Calorimeter, William J. Pochron
An Event-By-Event Comparison Of Clustering Algorithms For Photon Detection In The Star Endcap Calorimeter, William J. Pochron
Symposium on Undergraduate Research and Creative Expression (SOURCE)
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 …
Dispersion Of Radon-222 Gas In Air, Erin Beckmeyer
Dispersion Of Radon-222 Gas In Air, Erin Beckmeyer
Symposium on Undergraduate Research and Creative Expression (SOURCE)
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, but …
Generating A ‘Clean’ Pi0 Spectrum In Star, William J. Pochron
Generating A ‘Clean’ Pi0 Spectrum In Star, William J. Pochron
Symposium on Undergraduate Research and Creative Expression (SOURCE)
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 of the photons …
Stability Of The Gains Of The Star Endcap Calorimeter From 2006 To 2011, Kayla Kutz
Stability Of The Gains Of The Star Endcap Calorimeter From 2006 To 2011, Kayla Kutz
Symposium on Undergraduate Research and Creative Expression (SOURCE)
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 the gains …
Testing The Klein-Nishina Model For Compton Scattering Of 0.662 Mev Photons With A Focus On Lower Scattering Angles, Joel Rogers
Testing The Klein-Nishina Model For Compton Scattering Of 0.662 Mev Photons With A Focus On Lower Scattering Angles, Joel Rogers
Symposium on Undergraduate Research and Creative Expression (SOURCE)
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 degrees.
A Study Of Light Variability In Dying Stars, Hannah Rotter, Aaron Seider, Austin Bain
A Study Of Light Variability In Dying Stars, Hannah Rotter, Aaron Seider, Austin Bain
Symposium on Undergraduate Research and Creative Expression (SOURCE)
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, …
Neutron Electric Dipole Moment: Research And Development, Benjamin Barber
Neutron Electric Dipole Moment: Research And Development, Benjamin Barber
Symposium on Undergraduate Research and Creative Expression (SOURCE)
The neutron's electric dipole moment (nEDM) serves as an important test of the Standard Model of particle physics and it's various alternatives. Various models of fundamental physics allow for different magnitudes for the nEDM, and recent experiments have begun to exclude some models. Valparaiso University is part of a collaboration of institutions working on an improved experiment to measure the nEDM, to be conducted at Oak Ridge National Laboratory in the next few years. The experiment will be performed at 0.4 Kelvin, and will involve the use of magnetic fields and very large electric fields. Research at Los Alamos National …
Studying The Variability Of Dying Stars, Austin Bain, Hannah Rotter, Aaron Seider
Studying The Variability Of Dying Stars, Austin Bain, Hannah Rotter, Aaron Seider
Symposium on Undergraduate Research and Creative Expression (SOURCE)
In this project, we are observing and analyzing the light variability in a class of dying stars. This involves observing then on clear nights, primarily at the Valparaiso University Observatory but also including a few nights at the SARA Telescope at Kitt Peak National Observatory in Arizona. Thus far this summer we have observed for 25 nights and we observed 31 stars. Some of them we observed on every clear night and others we observed once or twice a week. We are analyzing a subset of 18 of these. We find that they have varied in light by 12 to …
Calibrating The Star Endcap Electromagnetic Calorimeter Using Pi-O’S, Benjamin Barber
Calibrating The Star Endcap Electromagnetic Calorimeter Using Pi-O’S, Benjamin Barber
Symposium on Undergraduate Research and Creative Expression (SOURCE)
The default energy calibration of the STAR EEMC (Endcap ElectroMagnetic Calorimeter) uses the energy deposition of minimally ionizing particles (MIPs). An alternate method is to use pi-0's. We are reporting a preliminary proof-of-principle calibration method using pi-0's. This method reconstructs the invariant mass of photon pairs, assumed to be resulting from pi-0 decays, using standard two-body kinematics. When many photon pairs are analyzed, a peak is expected in the resulting invariant mass distribution near the pi-0 mass. Using the measured mass of this peak, and the known mass of the pi-0, a minimization routine adjusts the detector gains to optimize …
The Study Of Variability In Oxygen-Rich Proto-Planetary Nebulae, Kristie Shaw
The Study Of Variability In Oxygen-Rich Proto-Planetary Nebulae, Kristie Shaw
Symposium on Undergraduate Research and Creative Expression (SOURCE)
In this project, I am studying and analyzing the light and color variations for two proto-planetary nebulae (PPNe). PPNe is a stage in a star’s life where the star is in the process of losing its outer layers and exposing its core. I observed at the Valparaiso University Observatory, using the 0.4 meter telescope and an electronic camera to take digital images. I reduced these data using an image processing program to get the numerical data results. I plotted these results as a light curve showing the variation in brightness of the star versus time. By observing in three different …
The Effect Of Strong Electrostatic And Magnetostatic Fields On The Activity Of Radioactive Nuclides, Sam Schaub
The Effect Of Strong Electrostatic And Magnetostatic Fields On The Activity Of Radioactive Nuclides, Sam Schaub
Symposium on Undergraduate Research and Creative Expression (SOURCE)
This experiment seeks to measure the effect of strong electrostatic and magnetostatic fields on the decay constant of short-lived radioactive isotopes. Though it is assumed in modern radioactivity theory that such fields should not have any measurable effect, conclusive evidence utilizing modern equipment is absent from published literature. Samples have been monitored that exhibit beta-minus, beta-plus, electron capture, and internal conversion modes of radioactive decay. Radioactive nuclides chosen for this study include I-128, Cs-134, and Cu-64. The half-lives in this collection of radioactive nuclides range from 25 minutes to 12.7 hours. Sodium Iodide detectors are used to monitor the samples …
An Observational Study Of Variable Stars, Joel Rogers, Wesley Cheek
An Observational Study Of Variable Stars, Joel Rogers, Wesley Cheek
Symposium on Undergraduate Research and Creative Expression (SOURCE)
This past summer, we carried out an observational study of light variability in approximately 20 stars. Our goal was to document their changes in brightness, determine a period of the variability, and investigate whether their brightness changes were correlated with changes in color (and thus temperature). These stars are part of a special class of stars that have evolved beyond the red giant phase but have not yet become white dwarfs. Little is known about their variability during this phase. We observed them on almost every clear night during the summer of 2010. We then compared the data for this …
Initial Studies Of The Forward Gem Tracker, Malorie Stowe, David Grosnik
Initial Studies Of The Forward Gem Tracker, Malorie Stowe, David Grosnik
Symposium on Undergraduate Research and Creative Expression (SOURCE)
The spin of the proton is known to be produced by several constituents including quarks, antiquarks, and gluons. It has been the goal of STAR to measure the contribution of gluons and various sea quarks to the proton spin. The Forward GEM Tracker (FGT) is a newly constructed detector to be placed into STAR, which is located at the RHIC collider at Brookhaven National Laboratory. The FGT serves to track the position of forward going charged particles, produced in proton-proton collisions, as they travel towards the Endcap Electromagnetic Calorimeter (EEMC). This information will be critical in helping to determine the …
Verification Of Monte-Carlo Simulation For Star Endcap Electromagnetic Calorimeter, Kevin Miller
Verification Of Monte-Carlo Simulation For Star Endcap Electromagnetic Calorimeter, Kevin Miller
Symposium on Undergraduate Research and Creative Expression (SOURCE)
The STAR experiment at Brookhaven National Laboratory seeks to measure the source of the protons spin, a fundamental property of matter. To accomplish this measurement, a simulation method called Monte-Carlo will be used to model the true detector responses to proton-proton collisions. My work is to confirm the accuracy of the Monte-Carlo simulation for the Endcap Electromagnetic Calorimeter (EEMC). By comparing histograms of fundamental parameters from the Monte-Carlo simulated data and true data from 2006 experimentation, we will be able to test the simulations accuracy. When validated, the Monte-Carlo simulation will be used to achieve a greater understanding of the …
Radon Concentration In Basements, Joel Rogers
Radon Concentration In Basements, Joel Rogers
Symposium on Undergraduate Research and Creative Expression (SOURCE)
This summer I am studying radon gas concentrations in basements in the Valparaiso community area. Radon is known to be the second leading cause of lung cancer after smoking. After several years (more than twenty) of continuous radon inhalation, the human lungs can be impaired and can become cancerous. This study will help people be aware of a potential radon problem in their homes. The EPA recommends having a concentration of four picocuries per liter or less in each home. The experiment is performed by using an EPA approved radon testing apparatus that records the concentration each hour for up …
The Reduction And Reporting Of Data On Proto-Planetary Nebulae From Two Observatories, Wesley Cheek
The Reduction And Reporting Of Data On Proto-Planetary Nebulae From Two Observatories, Wesley Cheek
Symposium on Undergraduate Research and Creative Expression (SOURCE)
I am documenting the light variability in a sample of proto-planetary nebulae (PPNs) observed from two observatories. PPNs are stars in the stage of evolution between the AGB and planetary nebula phases. I analyzed the digital images of the data taken on 34 nights from the SARA-South observatory located in Cerro Tololo, Chile along with data taken from the SARA-North Observatory located in Tuscon, Arizona. This was done to obtain quantitative measurements of the brightness variations over time. Once I had this information for each object, I plotted light curves, which can be used to document the amplitudes and possible …
Searching For Binary Stars In Planetary Nebulae Using The Isis Image Subtraction Software, Samantha Schwartz
Searching For Binary Stars In Planetary Nebulae Using The Isis Image Subtraction Software, Samantha Schwartz
Symposium on Undergraduate Research and Creative Expression (SOURCE)
We explored the theory that binary central stars of planetary nebulae may be contributing factor in the formation of planetary nebulae. We searched for this photometric variability in central stars of planetary nebulae because consistent periodic variability is indicative of a close binary system. The variability of our targets was assessed with the image subtraction software, ISIS. We found that the central stars of the planetary nebulae Hen 2-84, NGC 6326, and K 1-22 showed clear variability. A preliminary light curve for Hen 2-84 showed periodic behavior, suggesting a binary system. Of the remaining targets observed, with sufficient data, five …
The Study Of Variability In Four Oxygen-Rich Proto-Planetary Nebulae, Kristie Shaw
The Study Of Variability In Four Oxygen-Rich Proto-Planetary Nebulae, Kristie Shaw
Symposium on Undergraduate Research and Creative Expression (SOURCE)
This summer, I have been working on a project to study the variability of four proto-planetary nebulae. Proto-planetary nebulae (PPNe) are evolved stellar objects that are in the process of losing their outer layers and in transition from a red giant star to a planetary nebula. Oxygen-rich PPNe, specifically, have a higher oxygen content in their nebula than they do carbon, and this occurs mainly in lower mass stars. This project includes combining our data from the VU Observatory with other published data, analyzing light curves of brightness versus time and looking for patterns, and performing period analysis using a …
Calibrating The Star Endcap Electromagnetic Calorimeter Using π-0'S, Benjamin Barber
Calibrating The Star Endcap Electromagnetic Calorimeter Using π-0'S, Benjamin Barber
Symposium on Undergraduate Research and Creative Expression (SOURCE)
The STAR Endcap ElectroMagnetic Calorimeter (EEMC) is an important tool for identifying the particles produced in the forward direction of the STAR detector. These particles are used in the study of the proton's intrinsic angular momentum. Current calibrations of the EEMC have relied on the energy deposition of minimally ionizing particles (MIPs). To verify the MIP-based calibration, we are re-calibrating it using the energy deposition of the di-photon pairs created by Ï€-0 decays. Using the position and initial energy calibration of the two photon events, we can reconstruct the invariant mass of the parent particle. When this analysis is performed …
A Mip-Based Energy Calibration Of The Star Endcap Electromagnetic Calorimeter, Zachary Nault
A Mip-Based Energy Calibration Of The Star Endcap Electromagnetic Calorimeter, Zachary Nault
Symposium on Undergraduate Research and Creative Expression (SOURCE)
One of the main goals of the STAR Spin Collaboration is to understand the intrinsic angular momentum of the proton. An integral part of this experiment is the Endcap Electromagnetic Calorimeter (EEMC). The EEMC is used in detecting particles produced from hard proton-proton collisions that end up in the forward direction or 'end' of the experimental apparatus. In order to use properly the data collected, the energy and position measurements in the EEMC need to be well-known. To accomplish this, an energy calibration of the EEMC was performed using minimum ionizing particles (MIPs). The important property of MIPs utilized was …