1. Muonium, Positronium, Proton Radius, and all that


    from UK College of Arts & Sciences / Added

    9 Plays / / 0 Comments

    Dr. Michael Eides University of Kentucky I will discuss physics of exotic muonium and positronium atoms, high precision quantum electrodynamic calculations of energy levels, and determination of the electron-muon mass ratio. I'll introduce the proton radius puzzle, discuss briefly the experimental data on muonic hydrogen, deuterium, and helium, and explain the status of the respective theory.

    + More details
    • New Ideas for Axion Dark Matter Detection


      from UK College of Arts & Sciences / Added

      13 Plays / / 0 Comments

      Dr. Peter Graham SLAC The axion is a well-motivated dark matter candidate, but is challenging to search for. We propose a new way to search for QCD axion and axion-like-particle (ALP) dark matter. Nuclei that are interacting with the background axion dark matter acquire time-varying CP-odd nuclear moments such as an electric dipole moment. In analogy with nuclear magnetic resonance, these moments cause precession of nuclear spins in a material sample in the presence of a background electric field. This precession can be detected through high-precision magnetometry. With current techniques, this experiment has sensitivity to axion masses below 10^-9 eV, corresponding to theoretically well-motivated axion decay constants around the grand unification and Planck scales. With improved magnetometry, this experiment could ultimately cover the entire range of masses below 10^-6 eV, just beyond the region accessible to current axion searches. A discovery in such an experiment would not only reveal the nature of dark matter and confirm the axion as the solution of the strong CP problem, but would also provide a glimpse of physics at the highest energy scales, far beyond what can be directly probed in the laboratory.

      + More details
      • New Perspectives for QCD


        from UK College of Arts & Sciences / Added

        34 Plays / / 0 Comments

        AdS/QCD, together with ``Light-Front Holography", provides an analytic, frame-independent color-confining first approximation to QCD, accounting for light-quark meson and baryon spectroscopy, hadronic form factors, and other hadronic observables. A remarkable holographic feature of hadron dynamics in AdS space in five dimensions is that it is dual to Hamiltonian theory in physical space-time, quantized at fixed light-front time. This light-front holographic principle provides a precise relation between the bound-state amplitudes in AdS space and the boost-invariant light-front wavefunctions describing the internal structure of hadrons in physical space-time. The hadronic eigensolutions of the light-front QCD Hamiltonian satisfy a single-variable relativistic equation of motion, analogous to the nonrelativistic radial Schr\"odinger equation. The color-confining potential is determined uniquely using a method based on conformally invariant quantum mechanics. The resulting potential is color-confining and reproduces the observed linear Regge behavior of the light-quark hadron spectrum in both orbital angular momentum and the radial node number. The pion mass vanishes in the chiral limit, and other features of chiral symmetry are satisfied. The elastic and transition form factors of the pion and the nucleons are also found to be well described in this framework. A number of novel phenomenological consequences will be discussed, including hadronization at the amplitude level.

        + More details
        • Nicolas Regnault


          from UK College of Arts & Sciences / Added

          15 Plays / / 0 Comments

          Nicolas Regnault presenting at the Great Lakes Strings 2013.

          + More details
          • Observation of the thermal Casimir effect and new limits on non-Newtonian forces in the micrometer range


            from UK College of Arts & Sciences / Added

            40 Plays / / 0 Comments

            Quantum theory predicts the existence of the Casimir force between macroscopic bodies, a force arising from the zero-point energy of electromagnetic field modes around them. I will report the experimental observation of the thermal Casimir force between two gold plates, due to thermal rather than quantum fluctuations of the electromagnetic field at room-temperature. The thermal Casimir force dominates over the quantum force for separations greater than a micrometer. We use our measurements to place new upper bounds on short-range exotic forces, arising, for example, in quantum gravity theories with extra dimensions.

            + More details
            • Onkar Parrikar


              from UK College of Arts & Sciences / Added

              113 Plays / / 0 Comments

              Onkar Parrikar presenting at Great Lakes String 2013

              + More details
              • Particle-wave duality with and without quantum spookiness.


                from UK College of Arts & Sciences / Added

                38 Plays / / 0 Comments

                Quantum interference explains the stability of matter, guided the construction of the laser, and its application led to medical imaging techniques. So what is this quantum interference about? The double-slit experiments for electrons is considered to be “the only mystery”, insofar as it concerns quantum interference. Feynman's account of these experiments is one of the most popular. To get as close to Feynman's description of double-slit diffraction we did some experiments. This includes closing individual slits on demand, and taking a movie of the build-up of the diffraction pattern one particle at a time. In recent work done in Paris, macroscopic particle-wave duality with bouncing oil droplets was demonstrated for the first time ever. This was supposed not to be possible. What does that mean for microscopic or quantum-mechanical particle-wave duality for electrons? This means a lot to an international group of physicists labeled to be a “band of rebels” according to Morgan Freeman’s show “Through the Wormhole”. However this is not what we have taught in the past three years to more than 100,000 high school students through our movie “The Challenge of Quantum Reality.” What is going on?

                + More details
                • Peer Observation at the University of St Andrews


                  from University of St Andrews / Added

                  45 Plays / / 0 Comments

                  Bruce Sinclair, Director of Teaching in the School of Physics and Astronomy at the University of St Andrews, gives an overview of how Peer Observation is used in his School. Also lecturers provide their feedback on how peer observation has helped them in improving their teaching methods.

                  + More details
                  • Peter Koroteev


                    from UK College of Arts & Sciences / Added

                    11 Plays / / 0 Comments

                    Peter Koroteev presenting at Great Lakes String 2013

                    + More details

                    What are Tags?


                    Tags are keywords that describe videos. For example, a video of your Hawaiian vacation might be tagged with "Hawaii," "beach," "surfing," and "sunburn."