Physics & Astronomy "Exploring the Quantum Vacuum with Ultra-Intense Lasers": Talk by Wendell T. Hill III, University of Maryland

Abstract: We are at the threshold of a new era in physics where we could potentially probe the foundational principles in physics associated with quantum electrodynamics (QED) in a ways dreamed about since the early days of quantum mechanics. This era is being ushered in by multi-petawatt (1015+ W) laser facilities, currently under construction around the world. Contemporary lasers can easily reach intensities between 1013 and 1016 W/cm2. In this range, matter (atoms and molecules) cannot survive without losing electrons and its internal structure being severely perturbed. Multi-petawatt lasers will be capable of reaching intensities in excess of 1025 W/cm2, a level where QED predicts the vacuum itself will to become distorted and begin to reveal, in new ways, its structure. Richard Feynman is credited with referring to QED as “the jewel of physics” for its ability to provide incredibly accurate predictions of the Lamb shift in hydrogen, the anomalous magnetic moment of the electron and the ground state of positronium (an atom formed by an electron and a positron). As a seamless weaving together of radiation, quantum mechanics and special relativity, QED unifies a host of phenomena with a small number of principles, such as atomic structure, the creation and annihilation of particles, condensed matter and chemistry, to name a few. In its handling of the vacuum, it provides a way to treat some very unsettling infinities like the self-energy and mass of the electron and Dirac’s negative energy sea. In this presentation we will discuss some of these issues and see how, within the next five to 10 years, petawatt lasers might be exploited to probe the vacuum, and in particular QED’s predictions as they relate to Dark Matter.