LNS Special Seminars - 2018


 

 


4:00 p.m., Kolker Room, 26-414


Frontiers in Nuclear Astrophysics

Zachary Meisel, Ohio University

Abstract:
When matter is added to one of the densest possible objects in the universe, does that object expand or contract in size? Where were the elements from zinc to tin made? Answers to these seemingly simple questions have remained elusive over a century of nuclear astrophysics research. Recent opportunities, including the dawn of multi-messenger astronomy and the upcoming Facility for Rare Isotope Beams, place us at a unique time to provide solutions. I will discuss ongoing work and future plans at the frontiers of nuclear astrophysics experiment, focusing on new techniques employing radioactive ion beams that will improve constraints on the properties of ultradense matter and the origin of the heavy elements. I will also discuss the interplay between nuclear physics and models of astrophysical phenomena, showing how new approaches to modeling can be used to prioritize experimental efforts. 


 


4:00 p.m., Kolker Room, 26-414


Revolutionizing High Energy Physics with Plasma Wakefield Acceleration

Spencer J. Gessner, CERN

Abstract:
High energy physics is currently at an impasse. The simplest supersymmetric models are disfavored by recent LHC results and decades of dark matter searches have seen nothing. Linear Colliders like the ILC and CLIC are ready to be built, but the HEP community is divided over funding a single large project at the expense of many others. Is there a technology that can deliver high-energy, high-quality particle beams, while remaining compact, efficient, and inexpensive? In this talk, I will discuss recent advances in beam-driven plasma wakefield acceleration and the critical next steps towards the first HEP applications based on plasma acceleration. 


 


4:00 p.m., Kolker Room, 26-414


Radio Searches for Neutrinos at the Cosmic and Energy Frontiers

Stephanie Wissel, California Polytechnic State University

Abstract:

Cosmic neutrinos probe fundamental physics at scales far beyond the reach of terrestrial accelerators or other cosmic messenger particles. The low expected flux of cosmic neutrinos drives the need for neutrino experiments to achieve larger exposures and lower thresholds. Radio experiments can achieve such large exposures by taking advantage of the coherent broadband radio emission resulting from ultra-high-energy (E›1017 eV) neutrino interactions. In this talk, I will review results from current radio experiments, like ANITA, and discuss future concepts, like BEACON and RNO/ARA, aimed at understanding cosmic engines and exploring particle interactions at the highest energies.


 


4:00 p.m., Kolker Room, 26-414


Precision Spectroscopy of “Hot” Atoms and Molecules

Ronald Fernando Garcia Ruiz, CERN

Abstract:

Measurements of atomic and molecular structures allow access to observables that are key to our understanding of the nuclear many-body problem, the study of fundamental symmetries, and the search for new physics. In the atom, for example, hyperfine structure measurements provide fundamental properties of the atomic nucleus: spins, electromagnetic moments, and charge radii. Moreover, a precise knowledge of the interaction between the nucleus and the surrounding electrons can provide constraints on the existence of new particles. On the other hand, molecular systems offer new opportunities to explore the nuclear electroweak structure. In this talk, I will present recent results from laser spectroscopy experiments of exotic atoms and molecules in extreme regions of the nuclear chart, where short-lived nuclei are produced in minuscule quantities (≺ 100 ions/s). The relevance of these results to the recent advances in nuclear theory, and their connection with some of the outstanding questions of nuclear science will be discussed. Future experimental developments that aim to extend the current limits of precision and sensitivity will be illustrated.


 


3:00 p.m., Kolker Room, 26-414


Black Holes: From Rejection, to Experimental Evidence, to Suprises and Misconceptions

Prof. Bruno Coppi, MIT

Abstract:

The difficult path of the Black Hole concept -- from Princeton where it blossomed originally, to (our) Cambridge -- is reviewed and re-lived. A series of surprises and misconceptions concerning astrophysical objects identified as Black Holes is illustrated, together with the mysteries that remain to be faced.