Nuclear Theory·nucl-th

Tuesday·April 23, 2024

10 papers—6 primary·4 cross-listed

07
Isotope-shift factors with quantum electrodynamics effects for many-electron systems: A study of the nuclear charge radius of $^{26 m}$ Al
Leonid V. Skripnikov · Sergey D. Prosnyak · Aleksei V. Malyshev · Michail Athanasakis-Kaklamanakis · Alex Jose Brinson · Kei Minamisono · Fabian C. Pastrana Cruz · Jordan Ray Reilly · Brooke J. Rickey · Ronald. F. Garcia Ruiz
A method for calculating the field shift contribution to isotope shifts in many-electron atoms, incorporating quantum electrodynamics (QED) effects, is introduced. We also implement the model QED approach to incorporate QED contribution to the nuclear recoil effect at the high-order correlation effects treatment level. The proposed computational scheme is used to revise the value of the root-mean-square (rms) nuclear charge radius of the isomer of aluminium-26, $^{26 m}$ Al. This radius is important for the global analysis of the $V_{u d}$ element of the Cabibbo-Kobayashi-Maskawa matrix. The difference in mean-square nuclear charge radii of $^{27}$ Al and $^{26 m}$ Al, obtained by combining the calculated atomic factors with recently measured isotope shift (IS) of the $3 s^{2} 3 p^{2} P_{3/2} \to 3 s^{2} 4 s^{2} S_{1/2}$ transition in Al, is $0.443 (44) (19) fm^{2}$ , where the first and second uncertainties are experimental and theoretical ones, respectively. The latter is reduced by a factor of 4 with respect to the previous study. Using this value and the known value of the rms charge radius of $^{27}$ Al, the resultant value $R_{c} (^{26 m}$ Al) = 3.132(10)~fm is obtained. With the improved accuracy of the calculated IS factors the error in $R_{c} (^{26 m}$ Al) is now dominated by the experimental uncertainty. Similar revision of rms charge radii is made for the $^{28}$ Al, $^{29}$ Al, $^{30}$ Al, $^{31}$ Al and $^{32}$ Al isotopes using existing IS measurements. Additionally, atomic factors are computed for the $3 s^{2} 3 p^{2} P_{3/2} \to 3 s^{2} 4 s^{2} S_{1/2}$ , $3 s^{2} 3 p^{2} P_{1/2} \to 3 s^{2} 5 s^{2} S_{1/2}$ and $3 s^{2} 3 p^{2} P_{3/2} \to 3 s^{2} 5 s^{2} S_{1/2}$ transitions in Al, which can be used in future experimental studies.
↳ physics.atom-phnucl-thphysics.chem-phPRA(2024)·9 citations
08
Local univalence versus stability and causality in hydrodynamic models
Roya Heydari🇮🇷 · Farid Taghinavaz🇮🇷
Our main objective is to compare the analytic properties of hydrodynamic series with the stability and causality conditions applied to hydrodynamic modes. Analyticity, in this context, implies that the hydrodynamic series behaves as a univalent or single-valued function. Stability and causality adhere to physical constraints where hydrodynamic modes neither exhibit exponential growth nor travel faster than the speed of light. Through an examination of various hydrodynamic models, such as the Muller-Israel-Stewart (MIS) and the first-order hydro models like the BDNK (Bemfica-Disconzi-Noronha-Kovtun) model, we observe no new restrictions stemming from the analyticity limits in the shear channel of these models. However, local univalence is maintained in the sound channel of these models despite the global divergence of the hydrodynamic series. Notably, differences in the sound equations between the MIS and BDNK models lead to distinct analyticity limits. The MIS model's sound mode remains univalent at high momenta within a specific transport range. Conversely, in the BDNK model, the univalence of the sound mode extends to intermediate momenta across all stable and causal regions. Generally, the convergence radius is independent of univalence and the given dispersion relation predominantly influences their correlation. For second-order frequency dispersions, the relationship is precise, i.e. within the convergence radius, the hydro series demonstrates univalence. However, with higher-order dispersions, the hydro series is locally univalent within certain transport regions, which may fall within or outside the stable and causal zones.
↳ hep-phhep-thmath-phmath.MP+11 citation
09
Topological susceptibility and axion potential in two-flavor superconductive quark matter
Fabrizio Murgana🇮🇹 · David E. Alvarez Castillo🇵🇱 · Ana G. Grunfeld🇦🇷 · Marco Ruggieri🇮🇹
We study the potential of the axion, $a$ , of Quantum Chromodynamics, in the two-flavor color superconducting phase of cold and dense quark matter. We adopt a Nambu-Jona-Lasinio-like model. Our interaction contains two terms, one preserving and one breaking the $U (1)_{A}$ symmetry: the latter is responsible of the coupling of axions to quarks. We introduce two quark condensates, $h_{L}$ and $h_{R}$ , describing condensation for left-handed and right-handed quarks respectively; we then study the loci of the minima of the thermodynamic potential, $Ω$ , in the $(h_{L}, h_{R})$ plane, noticing how the instanton-induced interaction favors condensation in the scalar channel when the $θ -$ angle, $θ = a / f_{a}$ , vanishes. Increasing $θ$ we find a phase transition where the scalar condensate rotates into a pseudo-scalar one. We present an analytical result for the topological susceptibility, $χ$ , in the superconductive phase, which stands both at zero and at finite temperature. Finally, we compute the axion mass and its self-coupling. In particular, the axion mass $m_{a}$ is related to the full topological susceptibility via $χ = m_{a}^{2} f_{a}^{2}$ , hence our result for $χ$ gives an analytical result for $m_{a}$ in the superconductive phase of high-density Quantum Chromodynamics.
↳ hep-phhep-thnucl-thPRD(2024)·11 citations
10
PM2D: A parallel GPU-based code for the kinetic simulation of laser plasma instabilities in large scale plasmas
Hanghang Ma · Liwei Tan · Suming Weng · Wenjun Ying · Zhengming Sheng · Jie Zhang
Laser plasma instabilities (LPIs) have significant influences on the laser energy deposition efficiency, hot electron generation, and uniformity of irradiation in inertial confined fusion (ICF). In contrast to theoretical analysis of linear development of LPIs, numerical simulations play a more and more important role in revealing the complex physics of LPIs. Since LPIs are typically a three-wave coupling process, the precise kinetic simulation of LPIs requires to resolve the laser period (around one femtosecond) and laser wavelength (less than one micron). In this paper, a full wave fluid model of LPIs is constructed and numerically solved by the particle-mesh method, where the plasma is described by macro particles that can move across the mesh grids freely. Based upon this model, a two-dimensional (2D) GPU code named PM2D is developed. It can simulate the kinetic effects of LPIs self-consistently as normal particle-in-cell (PIC) codes. Moreover, as the physical model adopted in the PM2D code is specifically constructed for LPIs, the required macro particles per grid in the simulations can be largely reduced and thus overall simulation cost is considerably reduced comparing with typical PIC codes. Moreover, the numerical noise in our PM2D code is much lower, which makes it more robust than PIC codes in the simulation of LPIs for the long-time scale above 10 picoseconds. After the distributed computing is realized, our PM2D code is able to run on GPU clusters with a total mesh grids up to several billions, which meets the typical requirements for the simulations of LPIs at ICF experimental scale with reasonable cost.
↳ physics.plasm-phnucl-thComput.Phys.Commun.(2024)·0 citations

Affiliations

first authorsco-authorsvia INSPIRE

Isotope-shift factors with quantum electrodynamics effects for many-electron systems: A study of the nuclear charge radius of 26mAl

Local univalence versus stability and causality in hydrodynamic models

Topological susceptibility and axion potential in two-flavor superconductive quark matter

PM2D: A parallel GPU-based code for the kinetic simulation of laser plasma instabilities in large scale plasmas

Affiliations

Isotope-shift factors with quantum electrodynamics effects for many-electron systems: A study of the nuclear charge radius of $^{26 m}$ Al