Seminars

LIGO Technical Seminars

LIGO Seminars are open to all scientists, engineers, educators and students who may wish to attend. Seminars are held in the LIGO Auditorium or in the multi-use room in LIGO's main building. Check the time and location on the schedule below. Many of our talks are scheduled as targets of opportunity arise. They may be finalized months in advance or with little advance warning. If you would like to be notified as these seminars are scheduled, send an e-mail to outreach(at)ligo-wa.caltech.edu and you will be added to our electronic notification service. You can find driving directions to LIGO (here.

25 March 2011 4:00 PM LIGO Auditorium	Dr. Mark Palmer Cornell University The CesrTA Electron Cloud R&D Program Abstract -- In March 2008, the Cornell Electron-positron Storage Ring (CESR) concluded twenty-eight years of colliding beam operations for the CLEO experiment. Since that time, CESR has been reconfigured as a damping ring test accelerator (CesrTA) for a program of electron cloud (EC) research with ultra low emittance beams. The instrumentation in the ring has been upgraded with local diagnostics for measurement of EC density and with improved beam diagnostics for the characterization of both the low emittance performance and the beam dynamics of high intensity bunch trains interacting with the EC. Finally a range of EC mitigation methods have been deployed and tested. This talk will provide an overview of the research and results from the current program as well as plans for an ongoing R&D program that is applicable to future low emittance rings. Mark Palmer received his PhD from Princeton University in 1993 having worked on experimental searches for intermediate range components of gravity. He then joined the high energy physics group at the University of Illinois and worked on the CLEO experiment at the Cornell Electron Storage Ring. While on CLEO he was a member of the silicon vertex detector group and served as run manager in 1997-98. In 2000 he joined the accelerator physics group at Cornell University. He is currently a member of the International Linear Collider Damping Ring design team and Project Director of the CESR Test Accelerator program which conducts a range of R&D for future low emittance rings.
10 Feb 2011 Noon Seminar Multi-use Room	Dr. Cigdem Capan Washington State University Tri-Cities "CeCoIn₅: An Unusual Superconductor" Abstract -- A hundred years after its discovery superconductivity is still a vibrant area of research in Materials Science. The search for new superconductors, even though it is primarily catalyzed by the promise of carrying and storing electricity without loss in an energy-hungry century, is also motivated by the search for fundamentally new mechanisms for superconductivity. In this context, much attention has been devoted to strongly correlated electron systems, an ever growing class of materials in which the electron-electron interactions are sufficiently strong to make the existing theory of metals obsolete. CeCoIn5 is a “heavy-fermion” member of this family and has been in the spotlight for the past ten years, ever since it was found to be a superconductor below a critical temperature of Tc=2.3K. Its unique magnetic field phase diagram is a testimony to the unusual interplay of antiferromagnetism and superconductivity and continues to foster new ideas about the origin of superconductivity. In this talk I will review the state-of-the-art knowledge on CeCoIn5 with an outlook on how it is shaping our current approach to quantum fluids. Dr. Cigdem Capan, the first Instructor of Physics at WSU Tri-Cities, earned a B.S. in Physics and a Ph.D in Condensed Matter Physics from Universite Paris VI and a M.S. from Ecole Normal Superieure, also in Paris. Her dissertation, entitled "Nernst Effect in Undoped Cuprates" started Dr. Capan on a path in condensed matter research that has taken her to Los Alamos National Laboratory, Louisiana State University and, prior to joining the WSU Tri-Cities faculty, the University of California at Irvine. At both LSU and UCI she shared teaching and research responsibilities.
9 Feb 2011 4:00 PM LIGO Auditorium	Dr. Shane Larson Assistant Professor of Physics, Utah State University "OASES IN THE DARK: Galaxies as Probes of the Cosmos" Abstract -- Galaxies are ubiquitous entities in modern astronomy and astrophysics, yet as recently as 100 years ago their true nature was unknown and vigorously debated. Today, galaxies are widely studied and used as indicators to understand the growth of structure in the Universe, the evolution of stars and matter, and the growth and fate of massive black holes. In this talk, we'll revisit the debates and observations that led to our current understanding of galaxies and galactic structure, discuss things that we still do not understand about galaxies, discover how modern astronomical research about galaxies is expanding our understanding of the Cosmos, and finally take note of how gravitational wave astronomy will play a role in expanding our understanding of the Milky Way. Professor Larson has served on the faculty of Utah State Unviersity since 2008. His research interests include gravitational wave physics, general relativity, gravitation, astrophysics, astronomy, and planetary dynamics. For more than a decade he has contributed to research on low-frequency gravitational waves and their astrophysical sources, particularly in the context of the Laser Interferometer Space Antenna (LISA). After earning a B.S. from Oregon State University and a M.S. and Ph.D from Montana State University, Professor Larson undertook postdoctoral fellowships at Caltech and Penn State University before acccepting faculty appointments at Weber State University followed by Utah State University. An avid astronomer, Professor Larson promotes astronomy through active public outreach.
2 Feb 2011 Noon Seminar Multi-use Room	Professor Gianpietro Cagnoli Center for Gravitational Wave Astronomy, University of Texas at Brownsville "Aspects of Fused Silica Suspensions for Advanced Detectors" Abstract -- Following the pioneering work of the Glasgow group on the GEO600 detector, fused silica suspensions are now the current solution for the Advanced Gravitational-wave Detectors LIGO and Virgo. After a general introduction on suspensions and on the characteristics of fused silica, the seminar will focus on several aspects of the fiber physics and production technology. Recent results on fiber dynamics and on a bending point measurement device will be given. Finally the proposed work on the detection of glitches in stressed silicate bonded samples will be briefly presented. Professor Cagnoli has researched final-stage suspensions for gravitational wave interferometers since his diploma thesis in 1993. In 1998 he received a Ph.D at the University of Perugia while developing a suspension for the Virgo interferometer. At the University of Glasgow he mounted the first fused silica suspensions on the GEO600 interferometer and served as Principal Investigator on a PPARC/EGO project to develop the first laser-based silca fiber drawing machine, descendants of which are now used in LIGO and Virgo. He moved to the University of Texas at Brownsville in 2010 to form a group on materials and thermal noise-related studies for gravitational wave detectors.
1 Dec 2010 4:00 PM LIGO Auditorium	Dr. Lynn Cominsky Sonoma State University Education and Outreach Lead and Press Officer, Fermi Telescope "Exploring the Extreme Universe with Fermi" Abstract -- The mission of NASA's Fermi Gamma-ray Space Telescope is to explore the most energetic and exotic objects in the cosmos: blazing galaxies, intense stellar explosions and super-massive black holes. Launched in June, 2008, the telescope observed approximately 1000 gamma-ray sources in its first year of operation. These observations include more than ten times the number of blazars previously identified, and the most sensitive measurements yet of very high-energy gamma-ray bursts over a wide range of energies. The Fermi telescope also has discovered pulsars that pulse only in gamma rays and the first "millisecond" pulsars - pulsars that flash extraordinarily often - to be seen in gamma rays. These observations, along with many others, offer new insight into the physical processes by which these cosmic objects operate. They may also spark evidence for or against theories including dark matter and quantum gravity. Dr. Cominsky will will showcase these and other exciting results from the mission and will explain how Fermi uses matter and anti-matter pair production to track gamma rays to their cosmic locations. Dr. Lynn Cominsky, Professor of Physics and Astronomy and chair of the Department at Sonoma State University, serves as the Education and Public Outreach (EPO) Lead and as the press Officer for the Fermi Gamma-ray Space Telescope. After receiving a Ph.D from MIT with a thesis entitled X-Ray Burst Sources, Cominsky managed various aspects of the Extreme Ultraviolet Explorer (EUVE) Satellite Project before joining the faculty at Sonoma State in 1986. She has participated as a Guest Investigator on a number of X-ray and gamma-ray satellite experiments. Her observational goals have been to increase the understanding of the physics of mass transfer in neutron star and blackhole X-ray binary systems. In addition to serving as Head of EPO for Fermi, Dr. Cominsky leads the EPO team for the Swift Explorer mission and for other missions under study in NASA's Physics of the Cosmos program. She has worked on the development of a wide variety of astrophysics educational materials. Through her academic work, her mission-related EPO efforts, her participation on a number of NASA subcommittees and her service to organizations such as the American Astronomical Society, Dr. Cominsky has accumulated significant experience in interpreting astronomical discoveries to the public.
29 Sept 2010 4:30 PM LIGO Auditorium	Professor Barry Barish California Institute of Technology Director, International Linear Collider GDE President Elect of the American Physical Society "Mysteries of the Universe: Quarks to the Cosmos" Abstract -- A new era of discovery in particle physics opened in September 2008 with the start-up of the Large Hadron Collider (LHC) at CERN. The International Linear Collider (ILC), currently under design, will explore the same energy range as the LHC using a different approach. By colliding electrons with positrons, the International Linear Collider would provide results with extraordinary precision, enabling the exploration of unknown regions of science - the "Terascale", so named after energies approaching Tera electronvolts (trillions of electronvolts or TeV). Based on experiments and discoveries over the last decades, physicists believe that the Terascale will yield evidence for entirely new forms of matter, and possibly even extra dimensions of space. These discoveries will tell us about the nature of the universe and how the laws of physics came to be. The ILC would provide a view of energies trillion times beyond its own - into the ultrahigh-energy realm where nature's force might become unified. After obtaining a Ph.D in Physics from the University of California, Berkeley in 1962, Barry Barish performed a series of important experiments in particle and high energy physics as a member of the physics faculty at Caltech. His research shed light on the quark substructure of the nucleon, on the weak neutral current (one of the building blocks of the Standard Model of particle physics), and on the massive nature of neutrinos. He served as the co-chair of the High Energy Physics Advisory subpanel that developed a long-range plan for U.S. high energy physics in 2002. Currently the Linde Professor of Physics, emeritus at Caltech and Director of the Global Design Effort of the ILC, he is a member of AAAS and the National Academy of Sciences and a former appointee to the National Science Board. Of particular significance in relation to his talk at LIGO is the fact that he served as the Director of the LIGO Laboratory from 1997 to 2005, overseeing the construction of LIGO's detector facilities and their attainment of design sensitivity while leading efforts to strengthen the international collaboration of gravitational wave detectors.
10 Sept 2010 Noon Seminar Multi-use Room	Dr. Evan Goetz Albert Einstein Institute, Hannover "Gravitational Wave Studies: Detector Calibration and an All-Sky Search for Spinning Neutron Stars in Binary Systems" Abstract -- Gravitational waves are a consequence of Einstein's General Theory of Relativity. Violent, exotic astrophysical sources are predicted to emit gravitational waves--ripples in spacetime that propagate across the Universe at the speed of light. The LIGO Laboratory has constructed three detectors in the United States to detect and study these waves. In this talk I will discuss three fundamentally different calibration methods used to characterize a key component of the detector and determine the overall sensitivity of the detector to gravitational waves. Then, I will describe a new analysis technique, called TwoSpect, to detect gravitational waves from unknown spinning neutron stars in binary systems and show the results from simulated and real detector data.
26 Aug 2010 Noon Seminar Multi-use Room	Professor Mario Diaz Professor of Physics, University of Texas at Brownsville, Texas Southmost College "A Short History of Gravitational Wave Detection: From Paradigm to Experiment" Abstract -- This is a non-expert talk which starts with the early history of gravitational wave theory from the first speculations after the formulation of the theory of general relativity to the outstanding questions that have troubled theorists for almost half a century. I will explain some of the doubts that Einstein had himself during the early thirties and the mystery behind the publication of the 1937 paper in the Journal of the Franklin Institute. The talk will also cover some of the early years of J. Weber's experiments and some of the debates originated in the claims for early detection during the 70's.
24 Aug 2010 Noon Seminar Multi-use Room	Professor Mario Diaz Professor of Physics, University of Texas at Brownsville, Texas Southmost College "Cosmological Gravitational Waves" Abstract -- One of the potential sources for which we search with the LIGO detectors is the stochastic gravitational wave background of cosmological origin. In this talk I give an elementary introduction to the possible mechanisms for the production of this background. I start with a simple introduction to a Newtonian sui-generis formulation of the Big-Bang theory and recapitulate some of the story behind the discovery of Penzias and Wilson. I will end with a "hand waving" explanation of the quantum behavior of general relativistic sources that could have given origin to gravitational waves in the early universe. This is non-expert talk for a general audience with knowledge only of basic physics and introductory calculus.
24 Oct 08	Professor Sukanta Bose Department of Physics and Astronomy, Washington State University, Pullman "Estimating the parameters of non-spinning binary black holes using ground-based gravitational-wave detectors: Statistical errors" Abstract -- We assess the statistical errors in estimating the parameters of non-spinning black-hole binaries using ground-based gravitational-wave detectors. While past assessments were based on partial information provided by only the inspiral and/or ring-down pieces of the coalescence signal, the recent progress in analytical and numerical relativity enables us to make more accurate projections using "complete" inspiral-merger-ringdown waveforms. We employ the Fisher information-matrix formalism to estimate how accurately the source parameters will be measurable using a single interferometric detector as well as a network of interferometers. Those estimates are further vetted by full-fledged Monte-Carlo simulations. We find that the parameter accuracies of the complete waveform are, in general, significantly better than those of just the inspiral waveform in the case of binaries with total mass M > ~20 M_sun. In particular, for the case of the Advanced LIGO detector, parameter estimation is the most accurate in the M=100-200 M_sun range. For such a system, the error in measuring the total mass and the symmetrized mass-ratio is reduced by an order of magnitude or more. Furthermore, for binaries located at a fixed luminosity distance d_L, and observed with the Advanced LIGO--Advanced Virgo network, the sky-position error is expected to vary widely across the sky: For d_L = 1Gpc, this variation ranges mostly from a fraction of a square-degree to about 10 square-degrees, with an average value of roughly a square degree. For the mass parameters as well as the sky-position, this improvement in accuracy is partly due to the increased signal-to-noise ratio (SNR) and partly due to the phase-information about these parameters harnessed through the post-inspiral pieces of the waveform. The error in estimating d_L is dominated by the error in measuring the orbital inclination angle and is roughly 8% for low-mass (M ~ 20M_sun) binaries and about a few percent for high-mass (M ~ 100M_sun) binaries. Some implications of our work to cosmology will be discussed.
4 September 08	Professor Willem T. H. van Oers Department of Physics and Astronomy, University of Manitoba; TRIUMF "From Hadronic Parity Violation to Parity-Violating Electron Scattering and Tests of the Standard Model" Abstract -- Searches for parity violation in hadronic systems started soon after the evidence for parity violation in β -decay of ⁶⁰Co was presented by Madame Chien-Shiung Wu and in π and μ decay by Leon Lederman in 1957. The early searches for parity violation in hadronic systems did not reach the sensitivity required and only after technological advances in later years was parity violation unambiguously established. Within the meson-exchange description of the strong interaction, theory and experiment are meeting in a set of seven weak meson-nucleon coupling constants as defined in the seminal paper of Desplanques, Donoghue and Holstein. Even today, after almost five decades, the determination of the seven weak meson-nucleon couplings is rather incomplete. Parity violation in nuclear systems is rather complex due to the intricacies of QCD, the theory of the strong interaction. More straight forward in terms of interpretation are measurements of the proton-proton parity-violating analyzing power or asymmetry (normalized differences in scattering yields for positive and negative helicity incident beams), for which there exist three precision experiments (from the University of Bonn, from PSI, and from TRIUMF). To date, there are new opportunities for theoretical interpretation using effective field approaches based on chiral perturbation theory. The situation with regard to the measurement of the parity-violating analyzing power or asymmetry in polarized electron scattering is quite different. Although the original measurements were intended to determine the electro-weak mixing angle, with the current knowledge of the electro-weak interaction and the great precision with which electro-weak radiative corrections can be calculated, the emphasis has been to study the structure of the nucleon, and in particular the strangeness content of the nucleon. A whole series of experiments (the SAMPLE experiment at MIT-Bates, the G0 experiment and HAPPEX experiments at Jefferson Laboratory, and the PVA4 experiment at MAMI) have indicated that the strange quark contributions to the charge and magnetization distributions of the nucleon are tiny. These measurements if extrapolated to zero degrees and zero momentum transfer have also provided a factor five improvement in the knowledge of the neutral weak couplings to the quarks as given in the PDG handbook. Choosing appropriate kinematics in parity-violating electron-proton scattering permits nucleon structure effects on the measured analyzing power to be precisely controlled. Consequently, a precise measurement of the 'running' of sin²(θ_W) or the electro-weak mixing angle has become in sight. The Q^p_weak experiment at Jefferson Laboratory is to measure this quantity to a precision of about 4%. This will either establish conformity with the Standard Model of quarks and leptons or point to New Physics as the Standard Model must be encompassed, as expected, in a more general theory required,for instance, by a convergence of the three couplings (strong, electromagnetic, and weak) to a common value at the GUT scale. The Q^p_weak experiment is to start taking data in 2010. The upgrade of CEBAF at Jefferson Laboratory to 12 GeV, will allow a new measurement of sin²(θ_W) in parity-violating electron-electron scattering with an improved precision to the current better measurement (the SLAC E158 experiment) of the 'running' of sin²(θ_W) away from the Z⁰ pole. Preliminary design studies of such an experiment show that a precision comparable to the most precise individual measurements at the Z⁰ pole (about ±0.00025) can be reached. The result of this experiment will be rather complementary to the Q^p_weak experiment in terms of sensitivity to New Physics.
8 May 08	Vanessa Lauberg Dept. of Astronomy, University of Maryland "Induced Mergers of Stellar-Mass Black Hole Binaries in Galactic Nuclei" Abstract -- Black holes are at once simple and mysterious. While they can be described completely just by their mass and spin, understanding the relationship between black holes and their host environments and even providing conclusive proof of their existence pose difficult challenges for scientists. WIth detection of gravitational radiation on the horizon, we are poised at the boundary of a new set of knowledge. Gravitational waves will soon take us out of the realm of indirect observation of black holes and allow us to "see" them once and for all. By forcing black holes out of hiding, detectors such as LIGO will not only give us insight into the formation and demographics of these objects, but will also test Einstein's theory of general relativity to an unparalled degree. Because of the weak nature of gravitational waves and the resultant challenges in data analysis, the success of these detectors depends in large part on a detailed understanding of the radiation sources. Mergers of black hole binaries are among the most important such sources. Close interactions between black hole binaries and stars in dense systems such as globular clusters have been studied as a mechanism for causing mergers. Galactic nuclei are also promising environments that have yet to be considered in depth. I will discuss a new potential formation channel for LIGO sources: mergers of black hole binaries in the centers of galaxies.
7 February 08	Dr. Stephan Schlamminger Dept. of Physics, University of Washington "Exciting Physics with Torsion Balances " Abstract -- The torsion balance made its debut in the late 18th century .Two hundred years later, the torsion balance is still the instrument of choice to measure weak forces at low frequencies. In my talk I will present two measurements we have performed recently at the University of Washington. First, we studied the forces produced by fluctuating contact potentials between two metallic surfaces. Understanding and modeling these forces is crucial for LISA (Laser Interferometer Space Antenna), a planned space based gravitational wave observatory. Second, we used a torsion balance that constitutes a composition dipole to search for equivalence-principle violating forces. I will present measurements that compare the horizontal acceleration of Titanium and Beryllium with a sensitivity of 3 fm/s^2. These allow us to place limits on equivalence-principle violations with ranges from 1m to infinity.
28 June 06	Ricco Bonicalzi University of Washington "A Lab-scale Test of the Inverse-square Law of Gravity" Abstract -- Many attempts to quantize gravity entail a violation of the inverse-square law. A new null torsion-pendulum experiment, operating at the nearby Battelle Gravitational Physics Laboratory (BGPL), looks for such a violation between macroscopic bodies separated by approximately 10cm. A unique feature central to the design is the configuration of the mass distribution of both the pendulum and source mass to provide high-sensitivity to the horizontal derivative of the Laplacian of the gravitational potential (a signature of a non-Newtonian force), while simultaneously strongly suppressing the coupling through Newtonian gravity. Come learn about this and other fundamental tests of gravity being pursued at BGPL. Ricco Bonicalzi has been working on the inverse-square law experiment for 3 years now in pursuit of a Ph.D. His life is currently split in half between the Tri-cities and his home in Seattle.
13 Feb 06	Professor Sukanta Bose Department of Physics and Astronomy, Washington State University, Pullman "Probing the existence of extra dimensions with gravitational-wave observations" Abstract -- At the turn of the last millennium, higher-dimensional braneworld physics presented a possible solution to the hierarchy problem. In these models the Universe that we probe with the standard-model fields is a 4-dimensional "brane" embedded in a 5-dimensional bulk, such that only gravity can traverse the full bulk. Essentially, the existence of such dimensions can sufficiently alter gravity at small length scales such that the energy scale for grand unification in these models gets reduced to as low as a TeV, which is within the reach of the Large Hadron Collider. Even if the unification scale were outside the reach of the LHC, gravitational-wave detectors might be able to probe the presence of these extra dimensions. Here, I describe gravitational wave (GW) signals in braneworld models that have been studied thus far. These include black hole quasi-normal modes and the stochastic GW background. I also examine the challenges that the novel aspects of these signals present to gravitational-wave astronomers, and the new physics that they might unravel.
14 Dec 05	Dr. Neil Gehrels Chief Scientist of the Gamma Ray, Cosmic Ray and Gravitational Wave Physics Branch, NASA Goddard Space Flight Center "Gamma-ray Burst Dicoveries with Swift" Abstract -- Core-collapse explosions of massive stars are the likely sources of long gamma-ray bursts (>2s). Short bursts have resisted characterization due to the difficulty in pointing telescopes at sources over such short time scales. The NASA satellite mission Swift locates bursts through its wide-field Burst Alert Telescope (BAT) and quickly slews to point its X-ray and UV/Optical telescopes at the source. Several short GRB episodes have been captured to date. Chandra, the HST and terrestrial telescopes have contributed to this program by observing X-ray and optical afterglows from GRB sources identified by Swift and by the HETE mission. Analysis of the data suggest that likely sources of short bursts are neutron star-neutron star or neutron star-black hole mergers. Mergers are of deep astrophysical interest, in part because of gravitational waves that are thought to arise from these events. Dr. Neil Gehrels is the Swift Principal Investigator. His research involves the building of space flight instruments to observe gamma-ray emissions from astrophysical objects and the analysis of instrument data. He is also Deputy Project Scientist for the NASA-led Gamma-ray Large Area Space Telescope (GLAST). Previously he has served with the ESA-led International Gamma-ray Astrophysics Laboratory and the Compton Gamma Ray Observatory. Dr. Gehrels received his Ph.D. in physics at Caltech in 1981 and has worked at Goddard since that time. He has authored numerous scientific publications and has received several awards including the NASA Outstanding Leadership Medal.
19 Oct 05	Professor Hartmut Gemmeke Forschungszentrum Karlsruhe, Institute for Data Processing and Electronics, Karlsruhe, Germany "Detection and Imaging of Cosmic Ray Air Showers by Radio Flashes" Abstract -- The nature of ultrahigh-energy cosmic rays (UHECRs) at energies > 10²⁰ eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within 50 Mpc through interactions with the cosmic microwave background. Also unclear is whether UHECRs consist of protons, heavy nuclei, neutrinos or gamma-rays. To resolve these questions, larger detectors with higher duty cycles and which combine multiple detection techniques are needed. Radio emission from UHECRs, on the other hand, is unaffected by attenuation, has a high duty cycle, gives calorimetric measurements and provides high directional accuracy. There are an inflationary rising number of new experiments using interactions of cosmic rays with air, water, and solids producing radio flashes. After a short description of these experiments the talk will focus on the detection of radio flashes from UHECRs with low-cost digital radio receivers. The LOPES experiment demonstrates for the first time that the radiation can be understood in terms the geo-synchrotron effect and has a coherent appearance. The results show that it should be possible to determine the origin, energy and composition of UHECRs with combined radio and particle detectors,and to detect ultrahigh-energy neutrinos.
12 April 05	Dr. Michael Martin Nieto Fellow, Los Alamos National Laboratory "The Pioneer Anomaly: The Data, Its Meaning and a Possible Test" Abstract -- The radio-metric Doppler tracking data from the Pioneer 10/11 spacecraft, from between ~ 0-70 AU, yields an unambiguous and independently confirmed anomalous blue shift drift of a_t = (2.92 ± 0.44) x 10^-18 s/s². It can be interpreted as being due to a constant acceleration of a_P = (8.74 ± 1.33) x 10^-8 cm/s² directed towards the Sun. No systematic effect has been able to explain the anomaly, even though such an origin is an obvious candidate. We discuss what has been learned (and what might still be learned) from the data about the anomaly, its origin, and the mission design characteristics that would be needed to test it. Future options are discussed. These include: (i) A never-done rigorous, detailed analysis of early data from close in to the Sun, (ii) use of data from the upcoming New Horizons mission to Pluto, and (iii) use of a dedicated mission, which is being considered by the European Space Agency.
01 April 05	Professor Willem T. H. van Oers Department of Physics and Astronomy, University of Manitoba "The Weak Charge of the Proton: A Search for New Physics" Abstract -- A new precision measurement of parity violation electron scattering from the proton at very low Q² and forward angles is prepared for execution at the Jefferson Laboratory. The experiment is a direct challenge to the predictions of the Standard Model of quarks and leptons and is a search for new physics. There exists a unique opportunity to carry out the first precision measurements of the weak charge of the proton, Q_W(p) = 1 - 4sin²(Θ_W), by building on technical advances that have been made at the Jefferson Laboratory's world-leading parity violating electron scattering program and by using the results of earlier experiments to constrain hadronic corrections. A 2200 hour measurement of the parity violating asymmetry in elastic electron-proton scattering at Q² = 0.03 (GeV/c)² employing 180 µA of 85% polarized beam on a 0.35 m long liquid hydrogen target will determine the proton's weak charge with 4% combined statistical and systematic errors. The Standard Model makes a firm prediction of Q_W(p) based on the 'running' of the weak mixing angle sin²(Θ_W) from the Z⁰ pole down to lower energies, corresponding to a 9 σ effect at the envisaged experiment. Any significant deviation of sin²(Θ_W) from the Standard Model prediction at low Q² would be a signal of new physics, whereas agreement would place new and strict constraints on Standard Model extensions. In the absence of new physics the envisaged experiment will provide a 0.3% determination of sin²(Θ_W), making this a very competitive standalone measurement of the weak mixing angle indeed.

10 May 04	Prof. Tim Melbourne Department of Geological Sciences, Central Washington University "Slow Earthquakes in Cascadia and Elsewhere"

02 Mar 04	Adam Burrows U. of Arizona "Multi-Dimensional Supernova Simulations" Abstract -- The mechanism of core-collapse supernovae is thought to hinge upon the multi-dimensional character of core dynamics. Whether rotation or convection in the protoneutron star is pivotal, theorists must now approach the issues of explosion, pulsar kicks, nucleosynthesis, and neutron star/black hole birth with an arsenal of progressively more sophisticated numerical tools. Radiation hydrodynamics, with the radiation being neutrinos, plays a central role and since the resulting dynamics is vigorously multi-dimensional, gravitational radiation is generated with respectable magnitudes. I will review the current status of supernova theory, with a focus on detectable signatures of gravitational radiation, neutrinos, and kicks. (telecast from Caltech)

17 Feb 04	Sergey Klimenko University of Florida "Excess Power Method in Wavelet Domain for Burst Searches" Abstract -- I will describe an excess power method in wavelet domain which is used for the LIGO gravitational wave burst searches. It works on the time-frequency data produced with the orthogonal wavelet transforms. It allows searching for wide range of the GW bursts by using different types of wavelets and various wavelet decomposition schemes. The method works for a coincidence of multiple interferometers. For better detection sensitivity the local time-frequency coincidence rules are used before the GW bursts are reconstructed. The method uses the rank non-parametric statistics for trigger selection and therefore it is robust with respect to the detector noise. Also I will present the results of study of the algorithm efficiency for simulated burst waveforms injected into LIGO data Presentation preview: pdf \| ppt

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LIGO is supported by the National Science Foundation. Any opinions, findings, conclusions or recommendations expressed here are those of the author(s) and do not necessarily reflect the views of the National Science Foundation