Fri·Dec 3, 2021Friday·December 3, 2021

1. 01*

   Ab initio predictions link the neutron skin of ${}^{208}$Pb to nuclear forces

   Baishan Hu🇨🇦 · Weiguang Jiang🇩🇪 · Takayuki Miyagi🇨🇦 · Zhonghao Sun🇺🇸 · Andreas Ekström🇸🇪 · Christian Forssén🇸🇪 · Gaute Hagen🇺🇸 · Jason D. Holt🇨🇦 · Thomas Papenbrock🇺🇸 · S. Ragnar Stroberg🇺🇸 · Ian Vernon

   Heavy atomic nuclei have an excess of neutrons over protons, which leads to the formation of a neutron skin whose thickness is sensitive to details of the nuclear force. This links atomic nuclei to properties of neutron stars, thereby relating objects that differ in size by orders of magnitude. The nucleus ${}^{208}$Pb is of particular interest because it exhibits a simple structure and is experimentally accessible. However, computing such a heavy nucleus has been out of reach for ab initio theory. By combining advances in quantum many-body methods, statistical tools, and emulator technology, we make quantitative predictions for the properties of ${}^{208}$Pb starting from nuclear forces that are consistent with symmetries of low-energy quantum chromodynamics. We explore $10^9$ different nuclear-force parameterisations via history matching, confront them with data in select light nuclei, and arrive at an importance-weighted ensemble of interactions. We accurately reproduce bulk properties of ${}^{208}$Pb and determine the neutron skin thickness, which is smaller and more precise than a recent extraction from parity-violating electron scattering but in agreement with other experimental probes. This work demonstrates how realistic two- and three-nucleon forces act in a heavy nucleus and allows us to make quantitative predictions across the nuclear landscape.

   ↳ nucl-thastro-ph.HEnucl-exNat.Phys.(2024)·317 citations
2. 02*

   A transport model study of multiparticle cumulants in $p+p$ collisions at 13 TeV

   Xin-Li Zhao🇨🇳 · Zi-Wei Lin🇺🇸 · Liang Zheng🇨🇳 · Guo-Liang Ma🇨🇳

   Flow-like signals including the ridge structure observed in small collision systems that are similar to those in large collision systems have led to questions about the onset of collectivity in nuclear collisions. In this study, we use the string melting version of a multi-phase transport (AMPT) model with or without the sub-nucleon geometry for the proton to study multiparticle cumulants in $p+p$ collisions at 13 TeV. Both versions of the model produce negative $c_2\{4\}$ values at high multiplicities. In addition, the dependence of $c_2\{4\}$ on the parton cross section is non-monotonous, where only a range of parton cross section values leads to negative $c_2\{4\}$. Furthermore, the AMPT model with sub-nucleon geometry better describes the multiplicity dependence of $c_2\{4\}$, demonstrating the importance of incorporating the sub-nucleon geometry in studies of small collision systems.

   ↳ nucl-thnucl-exPLB(2023)·21 citations
3. 03*

   Ab initio nuclear thermodynamics from lattice effective field theory

   Bing-Nan Lu🇨🇳 · Ning Li🇨🇳 · Serdar Elhatisari🇹🇷 · Dean Lee🇺🇸 · Joaquín E. Drut🇺🇸 · Timo A. Lähde🇩🇪 · Evgeny Epelbaum🇩🇪 · Ulf-G. Meißner🇩🇪

   We show that the {\it ab initio} calculations of nuclear thermodynamics can be performed efficiently using lattice effective field theory. The simulations use a new approach called the pinhole trace algorithm to calculate thermodynamic observables for a fixed number of protons and neutrons enclosed in a finite box. In this framework, we calculate the equation of state, the liquid-vapor coexistence line and the critical point of neutral symmetric nuclear matter with high precision. Since the algorithm uses a canonical ensemble with a fixed number of particles, it provides a sizable computational advantage over grand canonical ensemble simulations that can be a factor of several thousands to as much as several millions for large volume simulations.

   ↳ nucl-thcond-mat.stat-mechhep-latnucl-exPoS(2022)·0 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.