Lawrence Livermore National Laboratory



Ron Soltz

Overview

We sought a fundamental advance in the treatment of probabilistic modeling as it applies to nuclear fission calculations of nuclear database inputs and produced particle distributions in heavy-ion collisions. This project proceeded through three stages. The fission task led to the development of a proof-of-principle Gaussian process emulator for time-dependent generator coordinate method calculation for the fission of 240Pu. The fission task led to the development of a proof-of-principle Gaussian Process Emulator for time-dependent generator coordinate method (TDGCM) calculation for the fission of Pu-240. To study energy loss in heavy-ion collisions with a probabalistic model, we generated a training data set using the Pythia event generator superimposed on a heavy-ion background with a single quench-factor parameter. We then used kernel density estimation to recover the distribution of quench-factors for a calibration data set. In the third stage, we proceeded to work through collaborations, collecting new data within the ATLAS experiment at the Large Hadron Collider and further developing Bayesian methodology within the Jet Energy-Loss Tomography with a Statistically and Computationally Advanced Program Envelope Collaboration.

Impact on Mission

This work supports Lawrence Livermore National Laboratory's core competencies in nuclear, chemical, and isotopic science and technology through advances in nuclear theory and experiment. This effort addressed Laboratory research challenges to develop a microscopic theory of fission, an understanding of jets, and uncertainty quantification. This work delivered an emulator that will lead to fission-product yield uncertainties in the microscopic approach and information that will help set priorities for future programmatic measurements. Our research on jet finding will be used to assess performance and improve the design of a new jet detector for the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. Work on jet finding will be used to assess performance and improve the design of a new jet detector for RHIC. This new detector will undergo construction in preparation for data taking in 2022–23 and is also intended to serve as a baseline detector for the Electron Ion Collider (EIC), a top new-construction priority for the U.S. Nuclear Physics Community. This area is projected to train nearly 40 percent of PhDs in experimental nuclear physics in the near future, and, as such, is a vital component to maintaining a vibrant nuclear physics workforce at the Laboratory.

Publications, Presentations, Etc.

Angerami, A. 2018. "Measurement of Longitudinal Flow De-Correlations in Pb+Pb Collisions at sqrt(sNN) = 2.76 and 5.02 TeV with the ATLAS Detector." The European Physical Journal C. LLNL-JRNL-757517.

——— . 2018. "Measurement of Quarkonium Production in Proton–Lead and Proton–Proton Collisions at 5.02 TeV with the ATLAS detector." The European Physical Journal C. LLNL-JRNL-757518.

——— . 2018. "Prompt and Non-Prompt J/psi and psi(2S) Suppression at High Transverse Momentum in 5.02 TeV Pb+Pb Collisions with the ATLAS Experiment." The European Physical Journal C. LLNL-JRNL-757519.

——— . 2018. "Measurement of the Suppression and Azimuthal Anisotropy of Muons from Heavy-Flavor Decays in Pb+Pb Collisions at sqrt(sNN) = 2.76 TeV with the ATLAS Detector." Physical Review C. LLNL-JRNL-757520.

——— . 2018. "Measurement of Jet Fragmentation in Pb+Pb and pp Collisions at sqrt(sNN) = 5.02 TeV with the ATLAS detector." Physical Review C. LLNL-JRNL-757521.

——— . 2018. "Measurement of the Nuclear Modification Factor for Inclusive Jets in Pb+Pb Collisions at sqrt(sNN)=5.02 TeV with the ATLAS Detector." Physical Letters B. LLNL-JRNL-757522.

——— . 2018. "Observation of Centrality-Dependent Acoplanarity for Muon Pairs Produced via Two-Photon Scattering in Pb+Pb Collisions at sqrt(sNN)=5.02 TeV with the ATLAS Detector." Physical Review Letters. LLNL-JRNL-757523.

——— . 2018. "Correlated Long-Range Mixed-Harmonic Fluctuations Measured in pp, p+Pb and Low-Multiplicity Pb+Pb Collisions with the ATLAS Detector." Physics Letters B. LLNL-JRNL-757524.

——— . 2018. "Prompt and Non-Prompt J/psi Elliptic Flow in Pb+Pb Collisions at sqrt(sNN) = 5.02 TeV with the ATLAS Detector." The European Physical Journal C. LLNL-JRNL-757525.

——— . 2018. "Measurement of the Azimuthal Anisotropy of Charged Particles Produced in sqrt(sNN) = 5.02 TeV Pb+Pb Collisions with the ATLAS Detector." The European Physical Journal C. LLNL-JRNL-757526.

Cao, S., et al. 2017. "Multistage Monte Carlo Simulation of Jet Modification in a Static Medium." Phys. Rev. C. 96, 024909. doi:10.1103/PhysRevC.96.024909. LLNL-JRNL-740186.

Heinz, M. and R. Soltz. 2017. "Systematic Error Study for ALICE Charged-jet v2 Measurement." LLNL-TR-735297.

——— . 2017. "Understanding Uncertainties in Jet Quenching in High-Energy Nucleus-Nucleus Collisions." LLNL-POST-735420.

Heinz, M., et al. 2017. "Manual for the Jet Event and Background Simulation Library." LLNL-TR-738295.

Soltz, R. 2017. "Multistage Monte Carlo Simulation of Jet Modification in a Static Medium." Phys. Rev. C. 96. doi: 10.1103/PhysRevC.96.024909. LLNL-JRNL-740186.