Mon·Jan 9, 2023Monday·January 9, 2023

1. 01*

   The shape of gold

   Benjamin Bally🇫🇷 · Giuliano Giacalone🇩🇪 · Michael Bender🇫🇷

   Having a detailed theoretical knowledge of the low-energy structure of the heavy odd-mass nucleus ${}^{197}$Au is of prime interest as the structure of this isotope represents an important input to theoretical simulations of collider experiments involving gold ions performed worldwide at relativistic energies. In the present article, therefore, we report on new results on the structure of ${}^{197}$Au obtained from state-of-the-art multi-reference energy density functional (MR-EDF) calculations. Our MR-EDF calculations were realized using the Skyrme-type pseudo-potential SLyMR1, and include beyond mean-field correlations through the mixing, in the spirit of the Generator Coordinate Method (GCM), of particle-number and angular-momentum projected triaxially deformed Bogoliubov quasi-particle states. Comparison with experimental data shows that the model gives a reasonable description of ${}^{197}$Au with in particular a good agreement for most of the spectroscopic properties of the $3/2_1^{+}$ ground state. From the collective wave function of the correlated state, we compute an average deformation $\bar{\beta }(3/2_1^{+})=0.13$ and $\bar{\gamma }(3/2_1^{+})=40^{\circ }$ for the ground state. We use this result to construct an intrinsic shape of ${}^{197}$Au representing a microscopically-motivated input for precision simulations of the associated collider processes. We discuss, in particular, how the triaxiality of this nucleus is expected to impact ${}^{197}$Au+${}^{197}$Au collision experiments at ultrarelativistic energy.

   ↳ nucl-thnucl-exEPJA(2023)·39 citations
2. 02*

   Hard jet substructure in a multistage approach

   Y. Tachibana🇯🇵 · A. Kumar🇨🇦 · A. Majumder🇺🇸 · A. Angerami🇺🇸 · R. Arora🇺🇸 · S. A. Bass🇺🇸 · S. Cao🇨🇳 · Y. Chen🇺🇸 · T. Dai🇺🇸 · L. Du🇨🇦 · R. Ehlers🇺🇸 · H. Elfner🇩🇪 and 47 other authors

   We present predictions and postdictions for a wide variety of hard jet-substructure observables using a multistage model within the JETSCAPE framework. The details of the multistage model and the various parameter choices are described in [A. Kumar et al., arXiv:2204.01163]. A novel feature of this model is the presence of two stages of jet modification: a high virtuality phase [modeled using the modular all twist transverse-scattering elastic-drag and radiation model (MATTER)], where modified coherence effects diminish medium-induced radiation, and a lower virtuality phase [modeled using the linear Boltzmann transport model (LBT)], where parton splits are fully resolved by the medium as they endure multiple scattering induced energy loss. Energy-loss calculations are carried out on event-by-event viscous fluid dynamic backgrounds constrained by experimental data. The uniform and consistent descriptions of multiple experimental observables demonstrate the essential role of modified coherence effects and the multistage modeling of jet evolution. Using the best choice of parameters from [A. Kumar et al., arXiv:2204.01163], and with no further tuning, we present calculations for the medium modified jet fragmentation function, the groomed jet momentum fraction $z_g$ and angular separation $r_g$ distributions, as well as the nuclear modification factor of groomed jets. These calculations provide accurate descriptions of published data from experiments at the Large Hadron Collider. Furthermore, we provide predictions from the multistage model for future measurements at the BNL Relativistic Heavy Ion Collider.

   ↳ hep-phhep-exnucl-exnucl-thPRC(2024)·47 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.