Nuclear Theory·nucl-th

Friday·September 13, 2024

12 papers—4 primary·8 cross-listed

01
[Submitted on 11 Sept 2024]
Computing the QRPA Level Density with the Finite Amplitude Method
Antonio Bjelčić · Nicolas Schunck
We describe a new algorithm to calculate the vibrational nuclear level density of an atomic nucleus. Fictitious perturbation operators that probe the response of the system are generated by drawing their matrix elements from some probability distribution function. We use the Finite Amplitude Method to explicitly compute the response for each such sample. With the help of the Kernel Polynomial Method, we build an estimator of the vibrational level density and provide the upper bound of the relative error in the limit of infinitely many random samples. The new algorithm can give accurate estimates of the vibrational level density. Since it is based on drawing multiple samples of perturbation operators, its computational implementation is naturally parallel and scales like the number of available processing units.
Comments:
Preprint submitted to Computer Physics Communications
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2409.07644 [pdf]
Comput.Phys.Commun.(2025)·1 citation
02
[Submitted on 12 Sept 2024]
Color transparency in hard $p d$ collisions
A.B. Larionov🇷🇺
As one of the predictions of perturbative QCD, the effect of color transparency has been the focus of attention in the community studying modifications of hadrons in nuclear medium for several decades. The search for this effect in reactions involving heavy nuclei can be complicated by uncertainties in nuclear characteristics (nucleon density distributions and wave functions), which can affect the interpretation of experiments. In this work, we consider the reaction $d (p, pp) n$ at $p_{lab} = 15$ GeV/c caused by hard elastic $pp$ scattering, in which these uncertainties are actually reduced to the behavior of the deuteron wave function at large momenta. It is shown that for transverse momenta of the spectator neutron $\leq 0.4$ GeV/c the choice of the deuteron wave function cannot affect the identification of the color transparency effect. A simple method for studying color transparency in $dd$ collisions is also suggested based on the identification of quasi-free $p d$ interactions.
Comments:
10 pages, 5 figures, in Russian, accepted in PEPAN
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2409.07845 [pdf]
0 citations
03
[Submitted on 12 Sept 2024]
Quantifying the breakdown scale of pionless effective field theory
Andreas Ekström🇸🇪 · Lucas Platter🇺🇸
We use Bayesian statistics to infer the breakdown scale of pionless effective field theory in its standard power counting and with renormalization of observables carried out using the power-divergence subtraction scheme and cutoff regularization. We condition our inference on predictions of the total neutron-proton scattering cross section up next-to-next-to leading order. We quantify a median breakdown scale of approximately 1.4 $m_{π}$ . The 68% degree of belief interval is $[0.96, 1.69] m_{π}$ . This result confirms the canonical expectation that the pion mass is a relevant scale in low-energy nuclear physics.
Comments:
6 pages,5 figures and 2 pages of supplemental material
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2409.08197 [pdf]
PLB(2025)·14 citations
04
[Submitted on 12 Sept 2024]
First complete description of low-lying spectroscopy in $^{254}$ No
D. D. Dao🇫🇷 · F. Nowacki🇫🇷
In this work, we report the first complete shell-model description of low-lying structures of $^{254}$ No. Employing the Kuo-Herling effective interaction, the calculations are performed within the Discrete Non-Orthogonal Shell Model recently implemented with the angular-momentum Variation After Projection applied on non-axial wavefunctions. Our calculations show a striking agreement with the experimentally known spectroscopy: the \textit{Yrast} band, the $8^{-}$ ( $K = 8$ ), $3^{+}$ ( $K = 3$ ) and $1 0^{+}$ ( $K = 10$ ) isomers together with associated $K$ bands. We reproduce the recently measured Gallagher-Moszkowski splitting between the $3^{+}$ ( $K = 3$ ) and $4^{+}$ ( $K = 4$ ) band heads. We predict the appearance of a second $0^{+}$ state, in excellent agreement with recent new observation. In addition, we systematically examine the ground state spectra, dipole and spectroscopic quadrupole moments of even-even, odd-even, odd-odd nuclei from $A = 251$ to $A = 256$ , which are favourably reproduced. The present description of $^{254}$ No shows the ability of the Shell Model framework to describe the low-lying properties for such an exotic nucleus at the frontier of modern experimental nuclear physics research.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2409.08210 [pdf]
PRC(2026)·6 citations
05
[Submitted on 10 Sept 2024] (cross-list from quant-ph)
Towards few-body QCD on a quantum computer
J.J. Galvez-Viruet🇪🇸
Quantum computers are promising tools for the simulation of many-body systems, and among those, QCD stands out by its rich phenomenology. Every simulation starts with a codification, and here we succently review a newly developed compact encoding based on the identification between registers and particles; the quantum memory is divided into registers, and to each we associate a Hilbert space of dimension the number of degrees of freedom of the codified particles. In this way we gain an exponential compression over direct encodings for a low number of particles with many degrees of freedom. As an example we apply this encoding on a two-register memory and implement antisymmetrization and exponentiation algorithms.
Comments:
Proceedings of the 27th High-Energy Physics International Conference in Quantum Chromodynamis (QCD24)
Subjects:
Quantum Physics (quant-ph); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2409.06403 [pdf]
Nucl.Part.Phys.Proc.(2024)·0 citations
06
[Submitted on 11 Sept 2024] (cross-list from hep-ph)
Minimizing Selection Bias in Inclusive Jets in Heavy-Ion Collisions with Energy Correlators
Carlota Andres🇺🇸 · Jack Holguin🇬🇧 · Raghav Kunnawalkam Elayavalli🇺🇸 · Jussi Viinikainen🇺🇸
The first-ever measurement of energy correlators within inclusive jets produced in heavy-ion collisions, revealed by the CMS Collaboration, shows a clear enhancement at large angles relative to the proton-proton (p-p) baseline. However, interpreting this enhancement is complicated due to selection bias from energy loss, which also distorts the energy correlator heavy-ion to p-p ratio in the hadronization region, hindering our understanding of parton/hadron dynamics in a colored medium. In this Letter, we introduce a new ratio of energy correlator observables that removes the leading effects of selection bias from the two-point energy correlator spectrum (E2C). Pythia and Herwig simulations show that the impact of selection bias in the E2C is reduced by an order of magnitude, while sensitivity to any other medium modifications is retained. This quantity can be obtained directly from the experimental measurements presented by CMS, as illustrated in the accompanying note.
Comments:
5 pages, 2 figures, 1 page of supplemental material with 2 additional figures. v2 typo corrected. v3 as published in PRL
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2409.07514 [pdf]
PRL(2025)·30 citations
07
[Submitted on 11 Sept 2024] (cross-list from hep-ph)
Minimizing Selection Bias in Inclusive Jets in Heavy-Ion Collisions with Energy Correlators -- arXiv note
Carlota Andres🇺🇸 · Jack Holguin🇬🇧
This note serves as a companion to a Letter, where we introduce a new energy correlator-based observable designed to minimize the impact of selection bias due to energy loss in inclusive jets in heavy-ion collisions. Here, we apply the method outlined in the Letter to the first-ever measurement of energy correlators in heavy-ion collisions, recently released by the CMS Collaboration.
Comments:
A companion note to a letter released on the same day. 5 pages, 4 eye-catching figures. Error bands added to figure 4
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2409.07526 [pdf]
9 citations
08
[Submitted on 12 Sept 2024] (cross-list from hep-ph)
Optimal collision-energy range for realizing macroscopic high-baryon-density matter
Hidetoshi Taya🇯🇵 · Asanosuke Jinno🇯🇵 · Masakiyo Kitazawa🇯🇵 · Yasushi Nara🇯🇵
We investigate the volume and lifetime of the high baryon-density matter created in heavy-ion collisions and estimate the optimal collision-energy range to realize the high baryon-density region over a large spacetime volume. We simulate central collisions of gold ions for the center-of-mass energy per nucleon pair $s_{N N} = 2.4 - 19.6 GeV$ with a microscopic transport model JAM. We discover that the optimal range is around $s_{N N} = 3 - 5 GeV$ , where a baryon density exceeding three times the normal nuclear density is realized with a substantially large spacetime volume. Higher and lower energies are disfavored due to short lifetime and low density, respectively. We also point out that event-by-event fluctuations of the spacetime density profile are large, indicating the importance of the event selection in the experimental analysis.
Comments:
v3: 7 pages, 3 figures. Title matched to the published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2409.07685 [pdf]
PRC(2025)·7 citations
09
[Submitted on 12 Sept 2024] (cross-list from cond-mat.mes-hall)
Spin-hydrodynamics of electrons in graphene and magnetization due to thermal vorticity
Amaresh Jaiswal🇮🇳
We examine the framework of relativistic spin-hydrodynamics in the context of electron hydrodynamics in graphene. We develop a spin-hydrodynamic model for a (2 + 1)-dimensional system of fermions under the condition of small spin polarization. Our analysis confirms that thermal vorticity, which satisfies the global equilibrium condition, is also a solution to the spin-hydrodynamic equations. Additionally, we calculate the magnetization of the system in global equilibrium and introduce a novel phenomenon - thermovortical magnetization - resulting from thermal vorticity, which can be experimentally observed in graphene.
Comments:
6 pages, 1 figure
Subjects:
Mesoscale and Nanoscale Physics (cond-mat.mes-hall); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2409.07764 [pdf]
9 citations
10
[Submitted on 12 Sept 2024] (cross-list from hep-ph)
Unified study of nucleon and $Δ$ baryon spectra and their strong decays with chiral dynamics
Hui-Hua Zhong🇨🇳 · Ming-Sheng Liu🇨🇳 · Ru-Hui Ni🇨🇳 · Mu-Yang Chen🇨🇳 · Xian-Hui Zhong🇨🇳 · Qiang Zhao🇨🇳
In this work we systematically study both the mass spectra and strong decays of the nucleon and $Δ$ resonances up to the $N = 2$ shell within a unified quark model framework with chiral dynamics. In this framework we achieve a good description of the strong decay properties of the well-established nucleon and $Δ$ resonances. Meanwhile, the mass reversal between $N (1440) 1/ 2^{+}$ as the first radial excitation state and the $1 P$ -wave nucleon resonances can be explained. We show that the three-body spin-orbit potential arising from the one-gluon exchange can cause a large configuration mixing between $N (1520) 3/ 2^{-}$ and $N (1700) 3/ 2^{-}$ , and is also responsible for the large splitting between $Δ (1600) 1/ 2^{-}$ and $Δ (1700) 3/ 2^{-}$ . Some of these baryon resonances turn to weakly couple to the $N π$ , $N η$ , $K Λ$ , and $K Σ$ channels, which may answer the question why they have not been established in these channels via the $π N$ and $γ N$ scatterings. It shows that these ``missing resonances" may have large potentials to be established in the $N π π$ final state due to their large decay rates into either the $Δ (1232)$ or $1 P$ -wave nucleon resonances via the pionic decays. Further experimental search for their signals in charmonium decays at BESIII is thus strongly recommended.
Comments:
26 pages, 7 figures, 12 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2409.07998 [pdf]
PRD(2024)·20 citations
11
[Submitted on 12 Sept 2024] (cross-list from hep-ph)
First Extraction of Transverse Momentum Dependent Helicity Distributions
Ke Yang🇨🇳 · Tianbo Liu🇨🇳 · Peng Sun🇨🇳 · Yuxiang Zhao🇨🇳 · Bo-Qiang Ma🇨🇳
We report on the first global analysis of transverse momentum dependent helicity distributions of the proton. The analysis is performed at next-to-leading order with the evolution factor at next-to-next-to-leading-logarithmic accuracy. Nonzero signals are determined for up and down quarks and their $k_{T}$ -integrated polarization are consistent with analyses in collinear factorization, while the distributions of other flavors are loosely constrained by existing data. With increasing transverse momentum, quarks at large $x$ become less polarized while those at small $x$ become more polarized.
Comments:
8 pages, 3 figures; match the published version in Physical Review Letters, and include the Supplemental Material
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2409.08110 [pdf]
PRL(2025)·15 citations
12
[Submitted on 12 Sept 2024] (cross-list from nucl-ex)
Critical evaluation of reference charge radii and applications in mirror nuclei
Ben Ohayon
I present a critical review of absolute root-mean-square charge radii of stable nuclei from $Z = 3$ to $Z = 32$ , which includes a previously overlooked uncertainty in the combined analysis of muonic x-ray and electron scattering experiments. From these \textit{reference radii} and isotope shift measurements, I obtain those of 12 mirror pairs with a traceable and realistic uncertainty budget. The difference in radii between mirror nuclei is found to be proportional to the isospin asymmetry, confirming recent calculations by Novario \emph{et al}~[PRL~130, 032501]. Assuming that this linear relation holds across the nuclear chart, the fitted proportionality constant, combined with the revised known radii, predicts the radii of 73 previously unknown mirror partners. These are useful e.g., for benchmarking atomic and nuclear theory, calibrating entire chains, and as an input to nuclear beta-decay calculations. The radii of $(T = 1, T_{z} = 0)$ nuclei are interpolated assuming negligible isospin symmetry breaking. This completes a model-independent, high-precision extraction of the charge and weak radii of all nuclei involved in the testing of the unitarity of the CKM matrix.
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
arXiv:
2409.08193 [pdf]
Atom.Data Nucl.Data Tabl.(2025)·25 citations

Affiliations

first authorsco-authorsvia INSPIRE