This page lists all of the abstracts for the Fall 2016 colloquium series. For dates and speakers, see Colloquium.


"Searching for sterile neutrinos with MicroBooNE", Friday, September 9, 12:00pm, MH 629

 

Brandon Eberly, SLAC National Accelerator Laboratory

 
ABSTRACT: The discovery of neutrino oscillations has opened an exciting avenue for physics searches beyond the Standard Model. In particular, a variety of experimental anomalies over the past twenty years can be jointly interpreted as evidence for a new fundamental particle called the sterile neutrino. The MicroBooNE experiment, a 170-ton liquid argon time projection chamber (LArTPC) currently operating in the Booster neutrino beam at Fermilab, will probe one of the sterile neutrino anomalies while also providing critical input for the development of future large-scale LArTPCs. After reviewing the status of neutrino physics, this talk will describe the MicroBooNE experiment and present a number of initial results. Future prospects will be discussed, including the integration of MicroBooNE into the Fermilab short baseline neutrino program.

"Autonomous quantum to classical transitions", Friday, February 16, 12:00pm, MH 629

 

Jim Feagin, CSU Fullerton

 
ABSTRACT: The mechanism of the transition of a system from quantum to classical mechanics is of continuing interest. Practically it is of importance for the interpretation of measurements performed at macroscopic distances from a microscopic reaction. Here, an imaging theorem is presented which shows that the spatial wave function of any quantum system, propagating over distances and times large on an atomic scale, becomes proportional to the initial momentum wave function where the position and momentum coordinates define a classical trajectory. Currently, the quantum to classical transition is considered to occur via decoherence caused by interaction with an environment. The imaging theorem arises from unitary Schrödinger propagation and so is valid without any environmental interaction.

"Physics Problem Solving: Customizable Computer Coaches for Physics Online (C3PO)", Friday, February 30, 12:00pm, MH 629

 

Qing Ryan, Cal. Poly. Pomona

 
ABSTRACT: Problem solving skill is highly valued by employers and educators. Since introductory physics is a pre-requisite for nearly all science and engineering majors, it is an ideal gateway to teach problem solving. In this talk, I will introduce a set of computer programs that were developed to help students become better problem solvers by coaching them in the use of an expert-like framework. There are three parts to this talk: Pedagogical design of the computer coaches, Assessments, and Next generation coaches. These computer coaches are assessed from following aspects: Usage and usability, Usefulness perceived by students, and Educational impact on problem solving.

"Neutron Stars: Where Gravitation Theory Meets Nuclear Physics", Friday, October 14, 12:00pm, MH 629

 

Lee Lindbolm, UC San Diego

 
ABSTRACT: Neutron stars are created by the gravitational collapse of massive stars that have exhausted their nuclear fuel.  The bulk of the material in these stars is compressed to densities larger than those in the nuclei of normal atoms.  Their gravitational fields become nearly as strong as those at the surfaces of black holes.  In this talk I will explore some of the things we can learn about nuclear physics by applying our knowledge of gravitation theory to astronomical observations of these stars.

"Roles of an Optical Engineer at Celestron", Friday, October 28, 12:00pm, MH 629

 

Chris Griffo, Celestron

 
ABSTRACT: Amateur astronomy wouldn’t be what it is today without the advancement of some key technologies that have been developed by Celestron, such as the mass manufacturing of high quality Schmidt correctors. As an Optical Engineer, knowledge of physics and other engineering disciplines are crucial in the development of these technologies. In this presentation I will give a quick introduction into telescope design, the Schmidt corrector/camera, history of Celestron, key roles of an optical engineer and some of the new products Celestron has introduced. Along with these topics, I will also go into my path through the optics industry and steps I took before and after I graduated from the CSU Fullerton Physics Department.

"Electron-phonon Interaction in Nanostructures at sub-Kelvin Temperatures", Wednesday, November 2, 1:00pm, MH 629

 

Dragos Anghel, Horia Hulubei National Institute for Physics and Nuclear Engineering

 
ABSTRACT: Ultrasensitive nanoscopic detectors for electromagnetic radiation consist of thin metallic films deposited on dielectric membranes. The metallic films, of thickness d, of the order of 10 nm, form the thermal sensing element (TSE), which absorbs the incident radiation and measures its power flux or the photons’ energy. To achieve the sensitivity required for space born astronomical observations, the TSE works at temperatures of the order of 0.1 K. The dielectric membranes are used for the thermal insulation of the TSE and are of thickness of the order of 100 nm. In such conditions, the phonon gas in the detector assumes a quasi-two-dimensional distribution, whereas quantization of the electrons wavenumbers in the direction perpendicular to the film surfaces lead to the formation of quasi two-dimensional electronic sub-bands.
We analyze the heat power, P, between electrons and phonons at temperatures below 0.2 K, in detectors structures of such thicknesses. If we denote by Te the electron's temperature and by Tph the phonons temperature, we can write P ≡ P(0)(Te)-P(1)(Te,Tph); P(0) is the power “emitted” by the electron system to the phonons and P(1) is the power “absorbed” by the electrons from the phonons. Due to the quantization of the electronic states and the quasi-two-dimensional distribution of the phonon gas, P(d, Te)  and P(d,Tphshow very strong oscillations with d, forming sharp crests almost parallel to the temperature axes. In the valleys between the crests, ∝ T3.5eT3.5ph. From valley to crest, P increases by more than one order of magnitude and on the crests P does not have a simple power law dependence on temperature.
The strong modulation of P with the thickness of the film may provide a way to control the electron-phonon heat power and the power dissipation in thin metallic films. Eventually the same mechanism may be used to detect small variations of d or surface contamination.

"Bond-selective chemistry with low-energy electrons", Friday, November 4, 12:00pm, MH 629

 

Daniel Slaughter, Lawrence Berkley National Laboratory

 
ABSTRACT: Anion momentum imaging experiments are combined with electron scattering calculations to investigate the dynamics of dissociative electron attachment in isolated molecules. Electronic Feshbach resonances typically play a central role in dissociative electron attachment. In these resonances, a valence electron is excited to an unoccupied orbital and the incident electron is captured in the same orbital. For the case of methane, one triply-degenerate Feshbach resonance undergoes Jahn-Teller splitting through molecular distortions, leading to four observed final states, each having a 2-body and a 3-body dissociation with anionic products H- and CH2- and neutrals CH3, CH2, H2 or H. In ammonia, one resonance leads to H- + NH2 and NH2- + H, the latter resulting from non-adiabatic charge transfer. A higher energy resonance leads directly to H- and electronically excited NH2 and indirectly to NH2-. The dynamics of damage of isolated DNA and RNA bases by resonant low energy electrons will also be discussed.

"Colliding particles and their applications", Friday, November 4, 12:00pm, MH 629

 

Mark Zammit, Los Alamos National Laboratory

 
ABSTRACT:Chemical reactions are the basis of life, and accurately describing chemical reactions is thus of great importance to science and has major implications in innovation, industry and medicine. Collisions between electrons, atoms and molecules underlie these chemical reactions. However, after many decades and attempts, predictions of what happens during these collisions (involving molecules) have remained quantitatively inconsistent with measurements and the problem was largely unsolved.
To tackle this problem, researchers at Los Alamos National Laboratory and Curtin University in Australia have developed “the convergent close-coupling code” (CCC), to model the simplest collisions between electrons, positrons (anti-electrons), atoms and molecules. Starting from the first principles of Quantum Mechanics and utilizing super computers, the program very accurately calculates the probability of collision processes such as the ionization or excitation of a molecule.
To date the method has been applied to positron and electron scattering from molecular hydrogen H2 and electron (e-) scattering from the constituents of fusion plasmas: H2, its ions H2+ and the ions isotopologues. Results from these studies are in good agreement with experiments and will have direct implications in the modeling of fusion plasmas, design of aerospace materials (for atmospheric entry), astrophysics and atmospheric modeling. In this talk, I will describe the CCC method, present some recent results and discuss opportunities afforded to young researchers.

 

 

This page lists all of the abstracts for the Spring 2016 colloquium series. For dates and speakers, see Colloquium.


"Spinning, Poynting, Translating: Shining Light on a TIRF Field in Order to Visualize HIV Assembly", Monday, February 1, 1:00pm, MH 606

 

Daniel Johnson, Rockefeller University

 
ABSTRACT: Total Internal Reflection Fluorescence (TIRF) Microscopy is an illumination technique in which fluorophores near a microscope cover glass (within ~100 nm) are excited, while those further away from the cover glass are not. This selective illumination typically reduces noise compared to traditional microscopy methods, thus making it easier to study single biomolecule complexes, such as individual proteins, nucleic acids and viruses. In addition, TIRF illumination has a unique polarization geometry enabling excitation of fluorophores aligned perpendicular to the cover glass surface, which is particularly useful for studying cell membranes. Here a novel TIRF illuminator will be described which enables visualization of structural changes in HIV particles throughout assembly in living cells, and observation of viral particle scission from the cell membrane following formation. In addition, the recruitment timing (hijacking) of cellular factors necessary for virus scission will be presented. Quantifying these processes provides insight into how HIV forms and leaves a cell, leading to the eventual invasion of another host. Interrupting this process may be an important factor in reducing the spread of HIV.

"Biophysical Interactions with Nanomaterials", Wednesday, February 3, 1:00pm, MH 606

 

Ran Chen, Kansas State University

 
ABSTRACT: Nanoscale materials have become widely adopted in various biomedically or environmentally relevant applications. In order to stimulate and facilitate these applications, there is an urgent need for a better understanding of the biophysical interactions of these materials with biological systems, especially on the cellular and molecular level. In this seminar, I will first introduce a series of comparative investigations on the cellular interactions of nanomaterials with animal and plant cells, and with subcellular structures like plasma membrane, and subsequent impact on the membrane structure. Then I will discuss about molecular level interaction of a few types of commonly used nanomaterials with biological macromolecules like proteins; I will show these interactions are determined by nanomaterial surface features and their binding with protein amino acid residues. Such binding shows impact on both the protein secondary structures and the nanomaterials surface physical or chemical properties, and subsequently change their interactions with other subcellular structures. Lastly I will introduce a modeling framework to systematically study the physical forces involved in biomolecule-nanosurface interactions by statistically analyzing massive experimentally obtained binding data, and the application of this framework toward molecular binding prediction and nanomaterial characterization based on their surface physical/chemical properties.

"Active mechanics keeps our cells alive.", Friday, February 5, 2:00pm, MH 606

 

Wylie Ahmed, Institut Curie (France)

 
ABSTRACT: Unlike traditional materials, living cells actively generate forces at the molecular scale that change their overall structure and mechanical properties. This nonequilibrium activity is essential for cellular function, and drives processes such as division, migration, and organization. In the first part of this talk, I will discuss how cells throughout the body (e.g. muscle, heart, tissue, and brain) must act as active mechanical systems to keep us alive. In the second part, I will discuss recent advances that allow quantification of nonequilibrium activity in living cells that provide insight on the molecular-scale driving forces. An understanding of active mechanics in living cells will uncover the basic physical principles driving biological processes and inspire new advances in nonequilibrium physics and materials science.

"Dark Sunshine", Friday, April 22, 12:00pm, MH 606

 

Flip Tandeo, University of California Irvine

 
ABSTRACT: The particle identity of dark matter is one of the most pressing open questions in high energy physics. In this talk, we review recent theoretical and experimental progress in the search for dark matter and the existence of dark forces. We highlight a particular class of searches based on dark matter collecting in the Earth or Sun that subsequently annihilates into dark force particles that are the analog of the ordinary photon. The observation of this "dark sunshine" or "dark earthshine" would be a smoking-gun signature for dark matter that would confirm a set of theories that have become particularly interesting from a range of recent experimental hints for new physics.

"Observation of gravitational waves from merging black holes", Friday, April 29, 12:00pm, MH 606

 

Geoffrey Lovelace, California State University Fullerton

 
ABSTRACT: On September 14, 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) made the first observation of gravitational waves passing through Earth. This gravitational-wave signal (named GW150914) originated from a pair of merging black holes over a billion light years away. In this talk, I will discuss this observation, the methods that made it possible, and implications for the dawning age of gravitational-wave astronomy. I will also highlight contributions from student and faculty researchers in CSUF’s Gravitational-Wave Physics and Astronomy Center, including a comparison of the LIGO observation with supercomputer calculations of the merging black holes and the gravitational waves they emitted.
Hello and congratulations on your admission as a physics major to California State University Fullerton!
 
I'm writing on behalf of the Department of Physics to introduce ourselves and to encourage you to join our strong and growing group of majors. Please take a moment to check out our webpage and in particular the welcome page
 
A major strength of our department is undergraduate research. As a physics major at CSUF, you will have the opportunity to work directly with your professors on research in areas such as atomic and molecular physics theory and experiment, lambda-boo star astronomy, neutron star and black hole astrophysics, gravitational waves, laser physics and optics, theoretical quantum mechanics, physics education research, condensed matter physics, and nano-technology. If you're interested in learning more about any of these fields, please don't hesitate to send me a reply email. 
 
Another great reason to attend CSUF is that our graduates are very successful. We have a rigorous curriculum, dedicated teachers, and a very active physics club. Our students work together on many projects, take trips, and plan events (such as an upcoming visit from Bill Nye). This helps our majors learn about career opportunities, study for classes, and find grad schools. Our majors have been accepted to PhD programs at Caltech, Georgia Tech, LSU, Notre Dame, Syracuse, UC Irvine, UC Riverside, and others in the past several years, and many others have landed high paying jobs in industry.
 
Again, congratulations on your successful application! We hope you will join us.
 
If you have any questions about our department or the CSUF physics major, I encourage you to give me a call or send me a reply email.
 
Best regards,
Joshua Smith
Director, Gravitational-Wave Physics and Astronomy Center
Assistant Professor of Physics
California State University Fullerton
657-278-3716
This email address is being protected from spambots. You need JavaScript enabled to view it.
 

Congratulations on your admission as a physics major to California State University Fullerton!
 
I'm writing on behalf of the Department of Physics to introduce ourselves and to encourage you to join our strong and growing group of majors. Please take a moment to check out our webpage and in particular the welcome page
 
A major strength of our department is undergraduate research. As a physics major at CSUF, you will have the opportunity to work directly with your professors on research in areas such as atomic and molecular physics theory and experiment, lambda-boo star astronomy, neutron star and black hole astrophysics, gravitational waves, laser physics and optics, theoretical quantum mechanics, physics education research, condensed matter physics, and nano-technology.
 
Another great reason to attend CSUF is that our graduates are very successful. We have a rigorous curriculum, dedicated teachers, and a very active physics club. Our students work together on many projects, take trips, and plan events (such as last year's visit by Bill Nye). This helps our majors learn about career opportunities, study for classes, and find grad schools. Our majors have been accepted to PhD programs at Caltech, Georgia Tech, LSU, Notre Dame, Syracuse, UC Irvine, UC Riverside, and others in the past several years, and many others have landed high paying jobs in industry.
 
Again, congratulations on your successful application! We hope you will join us.
 
If you have any questions about our department or the CSUF physics major, I encourage you to call or email me.
 
Best regards,
Joshua Smith
Director, Gravitational-Wave Physics and Astronomy Center
Associate Professor of Physics
California State University Fullerton
657-278-3716
This email address is being protected from spambots. You need JavaScript enabled to view it.