Johns Hopkins University QuarkNet Center
Submitted by Anonymous (not verified)
on Friday, September 13, 2013 - 09:05
Description
Welcome to the Johns Hopkins University QuarkNet center. We meet on the campus of JHU and serve teachers in the surrounding area.
JHU Abstract 2014-Reconstructing Bosons and Mesons Using Data from CMS
Reconstructing Mass of W, Z Bosons and J/Psi Meson Using CMS Data
Adam Der (Hereford High School) Jeremy Smith (Hereford High School), Tyler Bradley (Towson high School), Dr. Morris Swartz (Johns Hopkins University)
The purpose of this research was to reconstruct the mass of the Z boson, W boson, and J/Psi meson by using data of the particles decay given to me by CMS. After reconstructing the mass these particles I also researched on how the CMS machine itself detects these particles and the particles they decay into. By reconstructing the mass of these particles I can better understand their movements along with the properties of the particles they decay into. Also I now better understand how these particles are detected through the CMS machine. When reconstructing the masses of these bosons and mesons I found that the Z boson has a mass of 91 GeV compared to its actual mass of 91.2 GeV, the W boson has a mass of 80 GeV compared to its actual mass of 80.4 GeV, and the J/Psi has a mass of approximately 3.1 GeV compared to its actual mass of 3.0969 GeV. An important relationship when reconstructing the mass of a W boson is the relationship between its transverse mass and its true mass. When looking at the transverse mass histogram of a boson you want to look for a drop off in the histogram. Right after the peak into the drop off is approximately the true mass of the boson. You must use this relationship for the W boson because this boson will decay in a lepton and a neutrino. The neutrino cannot be detected by the CMS machine so it is represented as missing transverse energy. Researching the mass and decays of Bosons and Mesons allows us to take a better look at high energy particles as well as anti particles that are produced during their decay.
JHU Abstract 2014-Gamma Ray Bursts
Gamma Ray Bursts
Luke Bender (Towson High School), Jeremy Smith (Hereford High School), Tyler Bradley (Towson high School), Dr. Morris Swartz (Johns Hopkins University)
The purpose of this research was to learn as much as possible about the history, cause,
and effects of gamma ray bursts as well as what they could tell us about our universe.
Gamma ray bursts are the brightest and most energetic events in the universe and occur
whenever a super massive star runs out of nuclear fuel or when 2 neutron stars orbiting
each other collide. When a super massive star explodes, the core will become a black hole
and expel energy as gamma rays in jets, and these bursts typically last from about 2
seconds to a few hundred seconds. With 2 neutron stars colliding, the burst is much
shorter, lasting a few hundred milliseconds to 2 seconds. The long gamma ray bursts are
far more common (~70%) in comparison to the short gamma ray bursts (~30%). There has
also been discovered neutron stars that have a much stronger magnetic field than normal.
These “magnetars” are hypothesized to be the cause of soft gamma ray repeaters, less
energetic gamma ray bursts are that repeatedly emitted. Gamma ray bursts typically occur
in galaxies billions of light years away, so these bursts help tell us about the early universe.
In fact, the oldest known thing in the universe was a star over 13 billion light years away that
caused a gamma ray burst. Additionally, if a super massive star were within a few
thousand light years away, then it could potentially destroy all life on Earth. In fact, it is
hypothesized that a gamma ray burst could have caused extinction before, but there is no
evidence.
JHU Abstract 2014-The Physics of Medical Detection Devices, Specifically MRI
The Physics of Medical Detection Devices, Specifically MRI
Emily Larkin (Hereford High School), Jeremy Smith (Hereford High School), Tyler Bradley (Towson High School), Dr. Morris Swartz (Johns Hopkins University)
8/8/14
The study of medicine is applied physics. As doctors use medical devices to make diagnoses or to understand natural or manufactured biological compounds, they are fundamentally using laws and equations of physics through computer modules. One such detection device is MRI (Magnetic Resonance Imaging). I used an pNMR (pulsed Nuclear Magnetic Resonance) machine to understand how a natural and induced magnetic field can create a response in compounds that ultimately leads to an MRI scan, a three-dimensional soft-tissue image, differentiating between blood, bone, and viscera. With the pNMR and knowledge of physics, I concurred that chemical compounds with various structures react with different amplitudes of pulses to the applied field (created with an electromagnet) due to the accessibility of the nucleus given shielding created by electrons surrounding the molecules. Although the pNMR machine used lacked the computing technology of an MRI to quickly differentiate and calculate these pulses, I saw the importance of optimizing the signal. I also observed that as the delay time between the A and B pulses increases, the amplitude of the subsequent B pulse decreases in the pattern of an exponential decay. I believe this is because as the time increases, on the scale of tenths of milliseconds, the number of atoms that "spin out" of the electric field in the z axis increases, meaning that they are "relaxed" and therefore will not contribute to the amplitude of the B signal. In medicine, such technology is important as the basis of MRI scans to detect irregularities inside the body, but it also is used in the direct study of biological compounds. NMR is one of the leading devices being used to comprehend the structure of macromolecules such as proteins, oligonucleotides, and oligosaccharides. It can also be used in drug manufacture as a way to understand the structure of new drugs, and how this structure plays into their functionality in the body. Obviously, as medicine is approaching an age where diagnosis and description is based on the genome and proteome, further applications of NMR are needed to meet the demand.
JHU Abstract 2014-The Accelerated Expansion of the Universe
The Accelerated Expansion of the Universe
Derek Bierly (Hereford High School), Danny Mahoney (Hereford High School), Jeremy
Smith (Hereford High School), Tyler Bradley (Towson High School), Dr. Morris Swartz (Johns Hopkins University)
The purpose of our research was to provide evidence for the acceleration of the expansion
of the universe. We researched the work of 2011 Physics Nobel Prize recipients Dr. Adam
Riess, Dr. Saul Perlmutter, and Dr. Brian Schmidt, and attempted to replicate their
investigation of the accelerated expansion of the universe through the examination of
redshifted Type Ia supernovae. Evidence of a disconnect between the observed and
predicted distances to these supernovae supports the accelerating universe theory. We
looked up many supernovae on the Hubble Legacy Archive and attempted to get spectral
data for them. If we had more time we would have acquired these spectra, and solved for
the redshift and distance of each supernova. The theory of the accelerated expansion of
the universe necessitates the existence of dark energy, a hypothetical form of energy
believed to account for this negative vacuum pressure and make up roughly seventy
percent of the universe. The percentage of the universe that is dark energy will continue to
increase as the universe expands due to dark energy’s constant density. Researching the
accelerating expansion of the universe allows us to better understand the fate of the
universe, which could be an eventual “Freeze,” instead of The Big Crunch, which was
previously hypothesized.
2014 JHU Summer Research - List of Topics + Posters
2014 QuarkNet Summer Research Program
The Johns Hopkins University
List of Topics
Luke B, Shaina F, Sylvie H, James M - Antimatter
Luke B - Gamma Ray Bursters
Derek B, Danny M - Evidence for Dark Energy
Adam D, Mike M - QuarkNet Data Portfolio CMS Mass Reconstructions
Anthony F - Possible Sources of Cosmic Rays
Mike M - The Cosmic Microwave Background
All Members - Cosmic Ray Muon Detector Studies
Subhashini A, Emily L - Medical Physics
2014 JHU Summer Research - Abstracts
The Johns Hopkins University
2014 QuarkNet Summer Research Internships
List of Abstracts
Subhashini A, Emily L - Medical Physics
Luke B, Shaina F, Sylvie H, James M - Antimatter
Derek B, Danny M - Evidence for Dark Energy
Adam D - QuarkNet Data Portfolio CMS Mass Reconstructions
Anthony F - Possible Sources of Cosmic Rays
Mike M - The Cosmic Microwave Background
All Members - Cosmic Ray Muon Detector Studies
2013 JHU Summer Research - Abstracts
2013 Quarknet Summer Research Internships
Abstracts
The Johns Hopkins University
Derek B & Danny M - Antimatter & CP Violation
Becky D, Reina D, Mariah H, Matey S - Muon Flux with Varying Solid Angle
Adam G, Mark Y - History of Dark Matter
Derek B, Brian K, Danny M, Trenton W - Effect of Weather on Muon Flux
Adam G, Mark Y - Effect of Angle on Muon Flux
Mark Y - CMS e-lab Z Decay
Brian K, Max C - Galaxy Survey
2013 JHU Summer Research - List of Topics
2013 Quarknet Summer Research Internships
The Johns Hopkins University
Derek B & Danny M - Antimatter & CP Violation
Becky D, Reina D, Mariah H, Matey S - Muon Flux vs. Solid Angle (file missing)
Adam G, Mark Y - History of Dark Matter
Mark Y - CMS e-lab Z Decay
Brian K, Max C - Galaxy Survey
2014 Workshop - Afternoon Activity - Photoelectric Effect with LEDs
JHU Quarknet Summer Workshop 2014
Afternoon Activity: Photoelectric Effect Apparatus
On this page you can find the following:
1) Original instructions (with materials list) for the building of the device
2) Steve Wonnell's addenda for modifying the device for (a) all LEDs permanently wired to a "dial" selector switch and (b) discrete adjustments to the LED brightness via a second dial for more quantitative measurements. Included:
--An updated list of parts
--Template to print and atttach to the underside of the lid, for drilling holes
--Schematic diagram for the wiring of the dial switches
--Photos of the device with light shield removed to see the tube, and in operation
4) An example of a lab activity from U. of Missouri KC, discovered by Sue Ann Ness, which has a good set of instructions and diagrams for this device.
5) Spectroscopic data for the LEDs (compressed into single .rar file) in CSV spreadsheet format; should be readable by LoggerPro
2014 JHU Workshop - List of Talks
Monday 28 July
9:00-10:00 Introduction to QuarkNet (Jeremy Smith)
10:00-11:00 Basics of the Standard Model (Dr. Petar Maksimovic)
11:00-12:00 The Photoelectric Effect & a Classroom Experimental Apparatus (PowerPoint) (Dr. Morris Swartz) (PDF Version)
Tuesday 29 July
Film: Particle Fever
11:00-12:00 Q&A (Dr. Jared Kaplan)
Wednesday 30 July
9:00-10:00 CMB History and Current Theory / Results (Dr. Mark Kamionkowski)
10:00-11:00 Latest Results from CLASS Experiment (Dr. Tom Essinger-Hileman)
11:00-12:00 Higgs Physics (Dr. Andrei Gritsan)
Thursday 31 July
9:00-10:00 CERN Summer Vacation (Kevin Martz)
10:00-11:00 Active Learning in Physics Education (Dr. Robert Leheny)
11:00-12:00 Black Holes (Dr. Julian Krolik)
Click here for accretion disk animation!
Friday 1 August
9:00-10:00 Physics of Climate Change (Dr. Bill Blair)
10:00-11:00 Diversity (or Lack Thereof) in Physics (Alice Sady)
11:00-12:00 History of Discovery; Future QuarkNet Activities & Planning (Dr. Morris Swartz)