Browsing by Author "Fries, Rainer"

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    Research Project
    New Directions in High Energy Nuclear Physics
    Cyclotron Institute; TAMU; https://hdl.handle.net/20.500.14641/508; National Science Foundation
    Among the four fundamental forces in nature the strong nuclear force stands out for being the least understood one. It drives many processes in the universe that are crucial for our existence. One particularly important aspect of the strong nuclear force is the existence of quark gluon plasma. If ordinary matter is heated up to temperatures of about 1,000,000,000,000 degrees, hotter than the core of the sun, atoms and molecules cease to exist and even protons and neutrons inside atomic nuclei melt. The remaining primordial soup of quarks and gluons filled the very early universe. We can recreate quark gluon plasma in our largest particle colliders by smashing heavy nuclei into each other. Experimental programs at the Large Hadron Collider in Europe and the Relativistic Heavy Ion Collider in the USA study the properties of quark gluon plasma. This project will support research that will improve our understanding of the formation and properties of quark gluon plasma in nuclear collisions. The PI and his collaborators will use computer simulations and advanced statistical methods to reach this goal. Funding is provided to support training for a graduate students and junior scientists in nuclear science. Quark gluon plasma in nuclear collisions emerges from the highly complex gluon fields that are initially created in nuclear collisions. The PI and his group will investigate these fields and their properties by studying how angular momentum of the droplets of quark gluon plasma is related to the initial angular momentum of the colliding nuclei. The same gluon fields will also be studied through their interaction with fast quarks. The PI and his group will be able to use the JETSCAPE framework for large scale computational simulations of nuclear collisions. They will study various aspects of jets and heavy quarks being quenched in quark gluon plasma. They will then extract properties of quark gluon plasma using multiple constraints. For example, the strength of quenching of quarks and heavy quarks, and the viscosity of quark gluon plasma can be independently measured and are mutually related. Testing these relations will be an important step towards a deeper understanding of the dynamics of quark gluon plasma. The PI and his group will also use advanced statistical methods and machine learning applied to data to understand the mechanisms of hadron formation from quarks and gluons. These results will be used to improve the state-of-the-art modeling of the hadronization process that is a crucial input to many calculations. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
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    Research Project
    SI2-SSI: Collaborative Research: Jet Energy-Loss Tomography with a Statistically and Computationally Advanced Program Envelope (JETSCAPE) (JETSCAPE)
    Cyclotron Institute; TAMU; https://hdl.handle.net/20.500.14641/508; National Science Foundation
    Microseconds after the Big Bang, the universe was filled with an extremely hot fluid called the Quark-Gluon Plasma. As the universe expanded, this plasma cooled and condensed into the building blocks of ordinary matter around us: protons, neutrons, and atomic nuclei. Droplets of this fluid, which exists only at temperatures above 2 trillion Kelvin, are generated and studied in the laboratory today using collisions of high-energy heavy ions at Brookhaven National Laboratory and CERN. A key method to study the Quark-Gluon Plasma is the generation of high-energy quarks and gluons in the collision, which interact with the hot plasma and emerge as "jets" of particles that are measured by experiments. These jets provide powerful tools to study the internal structure of the plasma, analogous to tomography in medical imaging. However, interpretation of jet measurements requires sophisticated numerical modeling and simulation, and comparison of theory calculations with experimental data demands advanced statistical tools. The JETSCAPE Collaboration, an interdisciplinary team of physicists, computer scientists, and statisticians, will develop a comprehensive software framework that will provide a systematic, rigorous approach to meet this challenge. Training programs, workshops, summer schools and MOOCs, will disseminate the expertise needed to modify and maintain this framework. The JETSCAPE Collaboration will develop a scalable and portable open source software package to replace a variety of existing codes. The modular integrated software framework will consist of interacting generators to simulate (i) wave functions of the incoming nuclei, (ii) viscous fluid dynamical evolution of the hot plasma, and (iii) transport and modification of jets in the plasma. Integrated advanced statistical analysis tools will provide non-expert users with quantitative methods to validate novel theoretical descriptions of jet modification, by comparison with the complete set of current experimental data. To improve the efficiency of this computationally intensive task, the collaboration will develop trainable emulators that can accurately predict experimental observables by interpolation between full model runs, and employ accelerators such as Graphics Processing Units (GPUs) for both the fluid dynamical simulations and the modification of jets. The collaboration will create this framework with a user-friendly envelope that allows for continuous modifications, updates and improvements of each of its components. The effort will serve as a template for other fields that involve complex dynamical modeling and comparison with large data sets. It will open a new era for high-precision extraction of the internal structure of the Quark-Gluon Plasma with quantifiable uncertainties. This project advances the objectives of the National Strategic Computing Initiative (NSCI), an effort aimed at sustaining and enhancing the U.S. scientific, technological, and economic leadership position in High-Performance Computing (HPC) research, development, and deployment. This project is supported by the Division of Advanced Cyberinfrastructure in the Directorate for Computer & Information Science & Engineering and the Physics Division and the Division of Mathematical Sciences in the Directorate of Mathematical and Physical Sciences.