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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 289 records · Page 16
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Gluon saturation effects in exclusive heavy vector meson photoproduction

We study exclusive J/ψ and ϒ photoproduction for proton and Pb targets in the high-energy limit, with the energy dependence computed using the linear Balitsky–Fadin–Kuraev–Lipatov and the nonlinear Balitsky–Kovchegov evolution equations. The difference between these two evolution equations can be directly attributed to gluon saturation physics. We find that for proton targets there is no difference between the two approaches at the energies of the currently available data, while for Pb targets in J/ψ production the data shows a clear preference for the evolution with gluon saturation.

UPC↗
DOE OSTI2024

Ising meson spectroscopy on a noisy digital quantum simulator

Abstract Quantum simulation has the potential to be an indispensable technique for the investigation of non-perturbative phenomena in strongly-interacting quantum field theories (QFTs). In the modern quantum era, with Noisy Intermediate Scale Quantum (NISQ) simulators widely available and larger-scale quantum machines on the horizon, it is natural to ask: what non-perturbative QFT problems can be solved with the existing quantum hardware? We show that existing noisy quantum machines can be used to analyze the energy spectrum of several strongly-interacting 1+1D QFTs, which exhibit non-perturbative effects like ‘quark confinement’ and ‘false vacuum decay’. We perform quench experiments on IBM’s quantum simulators to compute the energy spectrum of 1+1D quantum Ising model with a longitudinal field. Our results demonstrate that digital quantum simulation in the NISQ era has the potential to be a viable alternative to numerical techniques such as density matrix renormalization group or the truncated conformal space methods for analyzing QFTs.

Science & Technology - Other Topics↗
DOE OSTI2023

Production of $Υ(nS)$ mesons in Pb + Pb and $pp$ collisions at 5.02 TeV

A measurement of the production of vector bottomonium states, $Υ$(1S), $Υ$(2S), and $Υ$(3S), in Pb + Pb and $pp$ collisions at a center-of-mass energy per nucleon pair of 5.02 TeV is presented. The data correspond to integrated luminosities of 1.38 nb –1 of Pb + Pb data collected in 2018, 0.44 nb –1 of Pb + Pb data collected in 2015, and 0.26 fb –1 of $pp$ data collected in 2017 by the ATLAS detector at the Large Hadron Collider. The measurements are performed in the dimuon decay channel for transverse momentum ${p}_{T}^{μμ}$ < 30 GeV, absolute rapidity |$y^{μμ}$| < 1.5, and Pb + Pb event centrality 0–80%. The production rates of the three bottomonium states in Pb + Pb collisions are compared with those in $pp$ collisions to extract the nuclear modification factors as functions of event centrality, ${p}_{T}^{μμ}$, and $|y^{μμ}|$. In addition, the suppression of the excited states relative to the ground state is studied. The results are compared with theoretical model calculations.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗