When: Friday 5:00 pm
Where: B131
Who: Graduate students
(The seminar is organized by Regina Caputo and Stefan Kowalczyk)To the speakers:
The purpose of the seminar is to introduce the research, the researcher(s) and the students to another in an informal way. No hardcore lectures are expected, rather an overview of the research being done. In order to spare the minds of the students I think it is best to keep the talk under one hour. Typically 25 students show up.
Regina and Stefan do the groceries, the department pays for the pizzas and the speaker for the drinks. The costs for the drinks are usually around $25. The speaker can give the money at the talk. I will bring the receipt with me.
In order to announce the speaker, it would be good to sent me the title/abstract of the talk at the latest on thursday, the week before the week of the talk. Please let me know whether a projector and/or a laptop is needed.
Thanks for volunteering to speak. If you have any questions, please contact Regina
| Date | Speaker | Room | Title/Abstract |
| 2/2/2007 | Fred Walter | B131 | Dead Stars and WannaBes |
| Most of the stars in the sky are considerably smaller and fainter than our Sun. Among these are the brown dwarfs (technically not stars, but close), about the size of Jupiter, and the white dwarfs, and endpoints of stellar evolution that result in objects the mass of the Sun with the radius of the Earth. My current research in these areas focuses on: - young substellar mass objects in regions of star formation. How do these soon-to-be brown dwarfs form? Why don't they gain enough mass to become stars? - cataclysmic variables, close binary star systems consisting of a white dwarf accreting mass from a low mass secondary. What is the nature of the very low mass secondaries? The connection between these two seemingly unrelated areas is a cataclysmic binary called EF Eridani, whose secondary seems to be of substellar mass. It probably began as a star, but has been whittled down to something very different. I will present some of my current research on these objects, and will discuss the enabling technologies. | |||
| 2/9/2007 | Ben Ocko | B131 | Soft-Matter Physics at Brookhaven National Laboratory |
| Our scientific focus is to understand the effects of nanoscale confinement and the role of self-assembly in soft materials through the use of patterned templates and well-defined interfaces. We use synchrotron x-ray scattering, scanning probe and optical microscopy techniques to study fundamental properties of complex fluids, simple liquids, macromolecular assemblies, liquid crystals, polymers, and biomolecular materials. The challenges are (1) to understand liquids under nano-confinement, (2) how templates and confinement can be used to direct the assembly of biomolecular materials and diblock copolymer thin films, (3) to understand the fundamental interactions which give rise to similar self-assembly behavior for a wide variety of systems, (4) how the order correlates with function. Understanding structural aspects of self-assembly and thin organic films underlies many emerging organic based devices and energy technologies. | |||
| 2/16/2007 | Helmut Strey | B131 at 3:15 pm | What is a physicist doing in a Biomedical Engineering Department? (Note the time: 3:15 pm, instead of 5:00 pm!) |
| I will give an overview over my labs efforts in molecular self-assembly and single molecule experiments and how this research can be applied to technologies ranging from genetic analysis to fuel cells. | |||
| 2/23/2007 | Meigan Aronson | B131 | Why Aren't More Things Magnetic? |
| The research in our experimental group is focussed on understanding the stability of magnetic order in a variety of different systems. We are studying the world's least stable magnets- ordering strictly in the limit of zero temperature, where quantum mechanical fluctuations are directly reflected in the anomalous critical phenomena. Another project asks how many magnetic atoms are needed to enable magnetic order? Here we find that the magnetism is dynamical, and we explore ways in which we can control its stability through the custom synthesis of composite nanoparticles. | |||
| 3/2/2007 | Alan Calder | B131 | The hows and whys of blowing up stars |
| Supernovae are spectacular explosions that signal violent stellar deaths. These fascinating events involve many branches of physics and are perhaps the most powerful explosions observed in the cosmos. Supernovae produce and disseminate heavy nuclei, trigger star formation, and some cases are the the birthplace of interesting astrophysical objects such as pulsars and black holes. In addition, one homogeneous class of these events serves as "standard candles" for distance measurements probing the expansion history of the Universe and thereby the nature of the dark energy accelerating the expansion. I will describe these events and my efforts at numerically modeling both supernovae and the relevant basic physics. | |||
| 3/23/2007 | Thomas Hemmick | B131 | Collisions of heavy ions at high energies |
| 4/6/2007 | No seminar (Spring break) | - | - |
| - | |||
| 4/13/2007 | Rama Calaga | B131 | Opportunities in Accelerator & Beam Physics |
| High energy colliders are expensive endeavor and research opportunities are generally confined to big federal laboratories. In addition, unique research topics available in the field of accelerators may not make it to the list of available Ph.D. theses options due to lack of adequate representation in university faculty in this field. However, Stony Brook students have a big advantage of having Brookhaven facilities within easy reach to them. In this seminar I would like to present a brief overview of high energy colliders using RHIC as a primary example. I will discuss some of the multidisciplinary options available in the field of accelerators, including my experience as a former Stony Brook graduate in this field. Boaz Nash, a recent Stanford graduate and currently a Post-Doc at NSLS-II will discuss some opportunities specific to light sources. | |||
| 4/20/2007 | Ismail Zahed | B131 | TBA |
| 4/27/2007 (last one!) | Chris Jacobsen | B131 | Adventures with X rays, life, and energy |
| The x-ray optics group does research in three areas. We operate a scanning x-ray microscope at Brookhaven that's used for the study of nanoscale chemical speciation in organic samples, with applications in environmental science and biofuels. We have developed a specialized phase contrast detector which we use at Argonne Lab for quantitative measurements of mass and ultrastructure in biological specimens to go along with fluorescence measurements of trace metals. At Berkeley lab, we are developing lensless x-ray imaging methods for 3D imaging of frozen hydrated cells. I'll briefly outline these three areas of research and discuss opportunities for new projects. |
| Date | Speaker | Room | Title/Abstract |
| 9/22/2006 | Anand Sivaramakrishnan | B131 | Theoretical Instrumentation - Active and Adaptive Optics |
| New instrumentation costs a lot - the James Webb Space Telescope (JWST), a 6.5 m unfolding segmented mirror space telescope currently scheduled for launch in 2013 will cost ~3.5B dollars, and is the flagship NASA/ESA space mission. How do we know that its 18 1.3 m segments are likely to unfold properly and end up forming a virtual mirror surface with 140 nm of error? On the ground, a cutting edge 'Extreme Adaptive Optics' (ExAO) is being developed for the 8 m Gemini telescopes at a cost of more than 22M$ over the next four years. How do we persuade ourselves that this project, which is supposed to increase our ability to see faint planetary companions of nearby bright stars by two orders of magnitude, will actually correct atmospheric turbulence-induced distortion well enough to produce the desired science? The answer lies in early theoretical explorationsof possible instrumentation. I will sketch the way I performed JWST wavefront sensing and detector simulations to verify the essential and central concepts behind the deployment and phasing up of JWST. I will also explain my modeling of extreme adaptive optics systems using circa 1999 computing hardware, combined with simple physical principles and an optical trick called coronagraphy, to help astronomers understand where to focus this decade's efforts at direct imaging of extrasolar planets from the ground. | |||
| 9/29/2006 | Martin Rocek | B131 | String theory, supersymmetry, and geometry |
| In this informal talk, I will sketch what string theory is, why it is interesting, the role of supersymmetry, and the application to geometry. | |||
| 10/6/2006 | Wei Ku | B131 | Study of symmetry broken states of interacting particles in condensed matter systems |
| A simple introduction of the fascinating and rich physics in strongly interacting electronic systems will be given in this talk, followed by examples of our recent theoretical study of the complex symmetry broken phenomena in real materials. A rough idea will be conveyed on what is involved in researches applying "first-principles" computational methods, and what fundamental difficulties remained to be solved. Newly funded projects on correlated nanotubes will be briefly discussed, which offers job opportunities of research assistants to interested students. | |||
| 10/13/2006 | Jiangyong Jia | B131 | Probing the Quark Gluon Plasma |
| At extremely high temperature and density, the normal nuclear matter we experience every day ``melts'' into the so called Quark-gluon plasma (QGP) phase consisting of ``quasi-free'' quarks and gluons, a phase believed to have existed during the first 10 microseconds after our universe was born in the Big Bang. This QGP can be created by heating matter above a temperature of 170 millon electron volts. Experimentally, this is done by colliding two large nuclei (typically Gold or Lead) at very high energy. The resulting hot and dense fireball is expected to expand under its own pressure, and cool down. Properties of the QGP such as its temperature, pressure, chemical potential, viscosity, diffusion coefficient, speed of sound, etc. can be deduced from thousands of particles emitted from the fireball and detected with large scale particle detectors surrounding the interaction region. Such studies are being carried out in the PHENIX experiment at the Relativistic Heavy-ion Collider (RHIC) and planned for the ATLAS experiment at the Large Hadron Collider (LHC), respectively. Early results from RHIC suggest the formation of such a new state of matter. Significant progress has been made in understanding the properties of this matter in the past five years. I will show results from experiments at the RHIC, focusing on the remarkable properties revealed by high transverse momentum hadrons and back to back hadron pairs. I will also discuss the future perspective of jet measurements at LHC. | |||
| 10/20/2006 | Clark McGrew | B131 | Neutrino Oscillation and Nucleon Decay |
| In 1996, Super-Kamiokande was built as part of a program to study neutrino oscillations and proton decay. Since then, it has set the most stringent limits on proton decay, and provided the first clear contradictions to the current standard model of particle physics. I will describe the current SK and K2K experiments as well as the T2K experiment which is under construction, and how it relates to the study of neutrino oscillations and the search for proton decay. | |||
| 10/27/2006 | Jin Wang | B131 | Biological Physics: New Frontier in the New Century |
| In this talk, I will briefly survery the trend of the modern biological physics in the post genomic era. I will reveiw some active reserach areas such as protein folding, biomolecular interactions and cellular networks. I will also give an outlook to the future of biological physics in terms of the scientific development, career track and job market. | |||
| 11/3/2006 | Hal Metcalf | B131 | Manipulating free, neutral atoms |
| There are many ways to manipulate atoms. Using light, we can even do it with ground state atoms. Sometimes the manipulation is simply slowing down, and then we call it laser cooling. In our lab we are investigating very special, ultra-strong, optical forces. By contrast, using electrostatic fields on ground state atoms is ineffective, so we sometimes put them into very highly excited states (n ~ 20) where we can do better. But doing this efficiently is not straightforward, and in fact, the best way to do it is completely counterintuitive. | |||
| 11/10/2006 | Abhay Deshpande | B131 | What makes the nucleon spin? |
| For many decades we know that the
nucleon spin is 1/2 in quantum units, but we do not know what
constitutes that spin: Are the quarks responsible for the spin? -No,
this we know now for certain. The EMC experiment at CERN in 1989 and
the experiments that followed in the 1990s, at CERN, SLAC and DESY
confirmed that the quarks and antiquarks only contribute ~25% of the
nucleon spin. Where is the rest of
the spin? We do not yet know. Gluons that bind the quarks
together inside the nucleon, may be responsible, but the measurement
techniques available until now were not efficient enough to
precisely measure them. Earlier in this decade, the Relativistic Heavy Ion Collider,
RHIC was commissioned at Brookhaven
National Laboratory. It is the only high energy collider
in the world that can collide polarized protons. The RHIC Spin program
being pursued there has one of its focus: the role of the gluons in
determining the nucleon spin. The Stony Brook Spin group is a major
contributer and a leader in this field and works on this problem as
part of the PHENIX experiment. An exiting future with lots of results
lies ahead of us in the next five years, with large luminosities and
high beam polarizations expected in the next few years. While learning
about the nucleon spin, we also learn new and fundamental aspects of
strong interactions in the framework of Quantum Chromodynamics (QCD),
the modern theory of strong interactions, the discoverers of which
recently got the Nobel Prize in Physics. While the SBU Spin group focuses now on the measurement of gluon spin contribution to the nucleon spin, it also has played leading roles in the development the program at RHIC: including development of polarimeters for RHIC, development of new ideas and techniques of monitoring the proton spin orientation in the RHIC ring. Further it is one of the operational leaders of the PHENIX expeirment. While preliminary results on gluon spin contribution look surprisingly low, as we solidify them with more statistical precision, and improved systematic unecrtainties, we are also looking ahead and trying to understand what might lie ahead in this quest: to understand the role of orbital angular momentum, how could that be measured? What could be clues that it actually plays a role? These and such aspects of the nucleon spin issues and the SBU's spin group will be presented on Friday in my talk. The spin group will look for students within the next year, as the existing first round of students become ready to graduate. Summer job opportunities will be available. |
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| 11/17/2006 | Robert McCarthy | B131 | Collider-Based Particle Physics Research at Stony Brook |
| The High Energy Physics group at Stony Brook is working at three colliding-beam accelerators. At Fermilab we started the D0 experiment which has a long history of successes. Current efforts of the group include searches for the Higgs boson, a more precise measurement of the W mass, and measurement of Bs mixing. At the ATLAS experiment at CERN's Large Hadron Collider (which is supposed to turn on for physics in 2008) we are concentrating on the search for supersymmetry and other new phenomena, searches for the Higgs boson, and diffractive scattering. Work should begin in the summer of 2007 on detector development for the International Linear Collider, which has not yet been fully funded. | |||
| 11/24/2006 | No seminar (Thanksgiving weekend) | - | - |
| - | |||
| 12/1/2006 | Tom Bergeman | B131 | Theory Work on Bose-Einstein Condensates and on Alkali Dimer Molecular Structure |
| Experimental progress in laser cooling of atoms by people such as H. Metcalf of Stony Brook has lead to many new developments often with interesting questions and challenges for theory. One such development has been the achievement of a Bose-Einstein condensate (BEC), predicted by Einstein and Bose in 1926 but not observed until 1995, after methods for laser cooling of atoms had been developed. I have been working on several questions related to BEC, most recently with very valuable help from graduate students. Our studies of oscillations of condensates in a double well potential have been based on a new, more rigorous solution of the Gross-Pitaevskii equation for such a situation. To study damping of these oscillations, it would be extremely valuable to develop methods for solving the quantum Boltzmann equation. And going beyond double wells, there are questions of interest that arise from nonlinear interactions in a periodic potential. The second major area of work here concerns the possibility of producing cold diatomic molecules. The coldest temperatures have been achieved by starting with laser-cooled atoms, but subsequest steps of photoassociation and stimulated decay to the molecular ground state require an accurate model of the molecular energy levels. Although efforts in this area have been successful, there remains the question whether, if one could understand molecular hyperfine structure better, improved methods could be devised. | |||
| 12/8/2006 | Mike Simon | B131 | Formation of Stars, Their Populations of Planets and Brown Dwarfs, Free-Floating and Otherwise |
| My students and I address basic questions about star formation: What kinds of stars will a given star-forming region in a molecular cloud produce? Given that binary formation is probably the dominant mode of star formation for stars like the Sun, what will be the distribution of masses of its binary stars? How can astronomers determine the ages of the stars produced? Do the answers depend on the physical parameters of the star- forming region? I will describe how my students and I, together with collaborators world-wide, use state-of-the art insrumentation to answer these questions. | |||
| 12/15/2006 | Tour to Brookhaven National Lab | Sign up by sending an email to Regina. (And please let us know if you have a car!) | |
| 12/22/2006 | Winter break | - | - |
| - |