Session M1: Plenary Session II

The Photon: From Newton and Maxwell to Einstein and Schwinger

The photon concept has a strange history. From the beginning there has been debate whether light is particle-like as Newton suggested or wave-like as Young showed. This debate continued up to modern times and was in particular illuminated by Einstein’s discussion the fluctuations and entropy of electromagnetic radiation. Based on thermodynamic reasoning he came to the conclusion that light has both a particle and a wave side. In the mid ’20’s quantum mechanics in the Heisenberg-Schrödinger form came into being and the first papers on quantum electrodynamics. Simultaneously, the electron was being investigated both from the point of view of quantum field theory and the Schrödinger wave equation and it was shown that the Schrödinger equation is in a real sense the wave rendition of the quantum field theoretic description. One then naturally asks "whether it is possible to consider the Maxwell equations to be a kind of Schrödinger equation for light particles?" The answer is "yes".   

From Bugs to Bombs: X-Ray Standards for Homeland Security

After the September 11 and anthrax attacks in 2001, it became apparent that there were few national or international standards that could qualify the equipment that accompanied the dramatic expansion of x-ray and gamma-ray screening for explosives, special nuclear material, and other contraband. With >10000 IED (improvised explosive device) incidents annually, and global expenditures for transportation and commercial security in the hundreds of billions of dollars, there is a pressing need to develop, apply, and harmonize standards for x-ray and gamma-ray screening systems used to detect explosives. This talk reviews national and international measurement standards and trends for bulk-explosives detection. This project at NIST has led to a new suite of national and international standards that ensure both the imaging performance and the radiation safety of systems used to screen luggage, persons, vehicles, cargo, and left-behind objects. While offering a broad overview of the physics trends in security screening and threat mitigation using ionizing radiation, an in-depth case study in dosimetry is offered as applied to the metrology of a flying-spot of x rays used to scan persons for non-medical purposes.   

Penetrating the Particle Frontier In The Era of Precision Higgs Physics

The discovery of the Higgs Boson in 2012 was a great triumph for elementary particle physics, marking the end of a decades-long search for the elusive particle. That pivotal event prompted physicists to examine the properties of this new boson in great detail. Now, three years later, the ATLAS and CMS collaborations have combined their analyses of Large Hadron Collider data to create a sharp new image of the Higgs particle. New results provide precise measurements of the mass of the Higgs boson and the strength of its interactions with other elementary particles. This presentation summarizes our current knowledge of the Higgs boson, its connection to our broader understanding of the universe, and the implications for future searches for new phenomena.