Nuclear Theory·nucl-th

Friday·October 18, 2024

17 papers—7 primary·10 cross-listed

01
[Submitted on 16 Oct 2024]
An end-to-end generative diffusion model for heavy-ion collisions
Jing-An Sun🇨🇳 · Li Yan🇨🇳 · Charles Gale🇨🇦 · Sangyong Jeon🇨🇦
We train a generative diffusion model (DM) to simulate ultra-relativistic heavy-ion collisions from end to end. The model takes initial entropy density profiles as input and produces two-dimensional final particle spectra, successfully reproducing integrated and differential observables. It also captures higher-order fluctuations and correlations. These findings suggest that the generative model has successfully learned the complex relationship between initial conditions and final particle spectra for various shear viscosities, as well as the fluctuations introduced during initial entropy production and hadronization stages, providing an efficient framework for resource-intensive physical goals. The code and trained model are available at https://huggingface.co/Jing-An/DiffHIC/tree/main.
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2410.13069 [pdf]
PRC(2025)·10 citations
02
[Submitted on 17 Oct 2024]
Azimuthal Correlation Anisotropies in p + p Collisions Simulated by Pythia
Manuel Sebastian Torres🇨🇴 · Yicheng Feng🇺🇸 · Fuqiang Wang🇺🇸
Stimulated by the keen interest of possible collective behavior in high-energy proton-proton and proton-nucleus collisions, we study two-particle angular correlations in pseudorapidity and azimuthal differences in simulated p + p interactions by the Pythia 8 event generator. Multi-parton interactions and color connection are included in these simulations which have been perceived to produce collectivity in final-state particles. Meanwhile, contributions from genuine few-body nonflow correlations, not of collective flow behavior, are known to be severe in those small-system collisions. We present our Pythia correlation studies in a pedagogical way and report azimuthal harmonic anisotropies analyzed by several methods. We observe anisotropies in those Pythia simulated events qualitatively and semi-quantitatively similar to experimental data. Our findings highlight the delicate nature of azimuthal anisotropies in small-system collisions, and provide a benchmark helping improve data analysis and interpret experimental measurements in small-system collisions.
Comments:
11 pages, 13 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2410.13143 [pdf]
CPC(2025)·1 citation
03
[Submitted on 17 Oct 2024]
Systematics of supernumerary nuclear rainbow in inelastic $^{16}$ O+ $^{12}$ C scattering
Nguyen Hoang Phuc · Nguyen Tri Toan Phuc · Do Cong Cuong
We perform a systematic study of inelastic nuclear rainbow scattering for the \oc system to the 2 $^{+}$ (4.44 MeV) state of $^{12}$ C at incident energies of 100--608 MeV with the coupled-channels method. The recently generalized nearside-farside decomposition for inelastic scattering was applied in combination with the multichannel deflection function analysis to elucidate the origin of the nuclear rainbow phenomenon and the suppression of the primary and supernumerary Airy minima in the inelastic scattering cross section. The systematic evolution of the Airy minima for the excited 2 $^{+}$ (4.44 MeV) state of $^{12}$ C was unambiguously determined. Our work suggests that there is no clear shift in the positions of the first Airy minima and a small shift at low energies for the second and third Airy minima between the inelastic and elastic scattering cross sections. Using the $K$ -subamplitudes splitting technique combined with the generalized nearside-farside decomposition and deflection function, the distinct refractive pattern commonly suppressed in the inelastic heavy-ion scattering can be interpreted and provides new insights into the relationship between elastic and inelastic nuclear rainbow scattering.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2410.13234 [pdf]
PRC(2024)·0 citations
04
[Submitted on 17 Oct 2024]
Impact parameter dependence of the effect of background field on coupling constant in heavy ion collisions
Cong Li🇨🇳
We investigated the impact parameter dependence of the background field's effect on the coupling constant of the $γ γ \to l^{+} l^{-} γ$ process in heavy-ion collisions. The peripheral electric fields of heavy ions collide, and after photon annihilation into lepton pairs, the subsequent emission of radiation photons will be affected by the background field. Numerical estimates indicate that the dependence of this effect on the impact parameter is significant during this process.
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2410.13291 [pdf]
0 citations
05
[Submitted on 17 Oct 2024]
Negative moments as the signature of the radial density at small distances
M. Atoui🇫🇷 · M. Hoballah🇫🇷 · M. Lassaut🇫🇷 · J. Van de Wiele🇫🇷
The present paper proposes a robust evaluation of any radial density at small distances using negative-order radial moments evaluated in momentum space. This evaluation provides a valuable insight into the behavior of a given radial density in the vicinity of $r = 0$ , and puts strong emphasis on the importance of measuring form factors at large squared four-momentum transfer, a domain essential for the determination of negative order moments. A specific attention is paid to the regularization scheme directly affecting the numerical determination of the radial density's parametrization. The proposed method is applied to non-relativistic study cases of the nucleon electric ( $G_{E n}, G_{E p}$ ), and proton magnetic $G_{M p}$ form factors. The validation is performed through comparison of the results of the approach to the analytically determined Maclaurin expansion - in the vicinity of $r = 0$ - of the radial density function. The method is also applied to the relativistic Dirac form factor $F_{1}$ of the proton. In such a non-trivial case, the Maclaurin development might not exist for the radial density, rendering the determination from the proposed method extremely important.
Comments:
11 pages, 8 plots
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2410.13340 [pdf]
EPJA(2025)·0 citations
06
[Submitted on 17 Oct 2024]
Microscopic description of spontaneous fission based on a Gogny energy density functional including tensor contributions
R. Rodríguez-Guzmán🇰🇿 · L.M. Robledo🇪🇸 · R.N. Bernard🇫🇷
This paper extends previous studies on the impact of tensor forces in fission dynamics of neutron-deficient Thorium isotopes to other isotopic chains of heavy actinides and low-mass super-heavy nuclei. Calculations are carried out within a mean-field framework based on the Gogny-D1S parametrization supplemented with the D1ST2a perturbative tensor term as driving force. Fission barrier heights and spontaneous fission half-lives are used as benchmarks to analyze the impact of the tensor term. A significant reduction of fission barrier heights and half-lives is associated to the tensor component of the force.
Comments:
11 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2410.13435 [pdf]
J.Phys.G(2024)·5 citations
07
[Submitted on 17 Oct 2024]
Neutron-neutron distribution of the triton from pionless EFT
Tanja Kirchner · Matthias Göbel · Hans-Werner Hammer
We compute the neutron-neutron relative-energy distribution of the triton following the hard knockout of the proton in pionless effective field theory. This distribution can be used to study universality as well as to obtain information on the neutron-neutron interaction. Especially, one can infer the scattering length from fitting theory predictions for the shape of the distribution to experimental data. To obtain the distribution for the triton, we first solve the ground-state three-body problem using momentum-space Faddeev equations. Next, we include the neutron-neutron final-state interaction by applying the corresponding Møller operator to the ground state. We present leading-order (LO) and next-to-leading order (NLO) pionless effective field theory results with quantified uncertainties. At NLO, we include the effective ranges semi-perturbatively. We conclude, that pionless EFT works reliably as expected and that the neutron-neutron distribution of the triton shows a significant sensitivity to the scattering length.
Comments:
18 pages, 7 figures. Further explanations, discussions and appendices with figures added. Results unchanged. Accepted for publication in Phys. Rev. C
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2410.13789 [pdf]
PRC(2025)·1 citation
08
[Submitted on 16 Oct 2024] (cross-list from hep-ph)
Effects of threshold resummation for large- $x$ PDF in large momentum effective theory
Xiangdong Ji🇺🇸 · Yizhuang Liu🇵🇱 · Yushan Su🇺🇸 · Rui Zhang🇺🇸
Parton distribution functions (PDFs) at large $x$ are challenging to extract from experimental data, yet they are essential for understanding hadron structure and searching for new physics beyond the Standard Model. Within the framework of the large momentum $P^{z}$ expansion of lattice quasi-PDFs, we investigate large $x$ PDFs, where the matching coefficient is factorized into the hard kernel, related to the active quark momentum $x P^{z}$ , and the threshold soft function, associated with the spectator momentum $(1 - x) P^{z}$ . The renormalization group equation of the soft function enables the resummation of the threshold double logarithms $α^{k} ln^{2 k} (1 - x)$ , which is crucial for a reliable and controllable calculation of large $x$ PDFs. Our analysis with pion valence PDFs indicates that perturbative matching breaks down when the spectator momentum $(1 - x) P^{z}$ approaches $Λ_{QCD}$ , but remains valid when both $x P^{z}$ and $(1 - x) P^{z}$ are much larger than $Λ_{QCD}$ . Additionally, we incorporate leading renormalon resummation within the threshold framework, demonstrating good perturbative convergence in the region where both spectator and active quark momenta are perturbative scales.
Comments:
57 pages, 8 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2410.12910 [pdf]
JHEP(2025)·21 citations
09
[Submitted on 16 Oct 2024] (cross-list from hep-ph)
Sketching pion and proton mass distributions
Xiaobin Wang🇨🇳 · Zanbin Xing🇨🇳 · Lei Chang🇨🇳 · Minghui Ding🇨🇳 · Khépani Raya🇪🇸 · Craig D. Roberts🇨🇳
A light-front holographic model is used to illustrate an algebraic scheme for constructing a representation of a hadron's zero-skewness generalised parton distribution (GPD) from its valence-quark distribution function (DF) and electromagnetic form factor, $F_{H}$ , without reference to deeply virtual Compton scattering data. The hadron's mass distribution gravitational form factor, $A_{H}$ , calculated from this GPD is harder than $F_{H}$ ; and, for each hadron, the associated mass-density profile is more compact than the analogous charge profile, with each pion near-core density being larger than that of its proton partner. These features are independent of the scheme employed.
Comments:
7 pages, 6 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2410.13068 [pdf]
PLB(2025)·13 citations
10
[Submitted on 17 Oct 2024] (cross-list from hep-ph)
The Theoretical Study of $Σ^{+} p \to Λ a_{0}^{+} p$ Reaction
Yan Dai🇨🇳 · Aojia Xu🇨🇳 · Gang Li🇨🇳 · Mao Song🇨🇳 · Xuan Luo🇨🇳
We conducted a theoretical study on the process $Σ^{+} p \to Λ a_{0}^{+} p$ based on an effective Lagrangian approach. This model encompasses the excitation of intermediate states leading to the production of $Δ (1920)$ through $π^{+}$ and $K^{+}$ meson exchanges between the initial $Σ^{+}$ baryon and the initial proton $p$ , as well as the generation of $Δ (1940)$ via $π^{+}$ and $ρ^{+}$ meson exchanges. We provide predictions for the total and differential cross sections and discuss the potential impacts of cutoff parameters, off-shell effects, and branching ratios on the $Δ^{*} \to a_{0} p$ decay. Given the dominance of $Δ (1940)$ in the region close to the reaction threshold, this reaction is considered an ideal platform for deeply exploring the unique properties of the $Δ (1940)$ resonance. Through this approach, we can gain a more precise understanding of the intrinsic characteristics of this particle.
Comments:
13 pages,10 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2410.13207 [pdf]
Int.J.Theor.Phys.(2025)·0 citations
11
[Submitted on 17 Oct 2024] (cross-list from hep-ph)
Twist-3 contribution in the Drell-Yan process with tensor-polarized deuteron
Si-Yi Qiao🇨🇳 · Qin-Tao Song🇨🇳
The tensor-polarized structures of the deuteron can be probed through the proton-deuteron Drell-Yan process, where the proton is unpolarized and the deuteron is tensor polarized. This measurement will be conducted at Fermilab in the near future. In this reaction, the twist-3 contribution is not negligible compared to the twist-2 contribution due to the limited invariant mass of the dilepton pair. We calculate the twist-3 contribution for the Drell-Yan cross section with a tensor-polarized deuteron target, preserving the U(1)-gauge invariance of the hadronic tensor. The cross sections and weighted cross sections are expressed in terms of the tensor-polarized parton distribution functions (PDFs), thus one can extract the PDFs $f_{1 LL}$ , $f_{L T}$ , and $f_{1 L T}^{(1)}$ from the experimental measurements of Drell-Yan process. Our study should be helpful to solve the puzzle in the tensor-polarized structures of the deuteron.
Comments:
8 pages, 4 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2410.13225 [pdf]
PRD(2025)·4 citations
12
[Submitted on 17 Oct 2024] (cross-list from hep-ph)
Confined but chirally and chiral spin symmetric hot matter
L. Ya. Glozman🇦🇹 · A. V. Nefediev🇩🇪 · R. F. Wagenbrunn🇦🇹
We investigate properties of the quark--antiquark mesons at zero and finite temperature in the framework of a solvable chirally symmetric quark model with linear confining potential. The interquark interaction in the model is reminiscent of that derived in Coulomb gauge QCD, with the string tension being the only model parameter. We demonstrate that while the confining interaction induces spontaneous breaking of chiral symmetry at T=0, chiral symmetry gets restored at a temperature Tch ~ 90 MeV for the string tension fixed to provide the phenomenological value of the quark condensate. This temperature is similar to Tch ~ 130 MeV observed on the lattice in the chiral limit for N_c=3. The physical mechanism responsible for the chiral symmetry restoration in the confining regime is Pauli blocking of the quark levels, required for the existence of a nonvanishing quark condensate, by the thermal excitations of the quarks and antiquarks. Thus, above the chiral restoration temperature, the meson-like states are chirally symmetric and approximately chiral spin symmetric. A crucial property of the confined meson-like light-light states above Tch is their size that exceeds drastically that in the chirally broken phase below Tch, in contrast to the heavy-heavy mesons that nearly preserve their size irrespective of the temperature. This property is a result of Pauli blocking of the quark and antiquark levels with small momenta. Furthermore, the root-mean-square radius of the states with J=0,1 diverges in the chiral limit. This unexpected property must be a key to understanding unusual features of the hot QCD matter as observed at RHIC and LHC. Consequently, the confining but chirally symmetric matter above Tch can be considered as a dense system of very large and strongly overlapping meson-like states (``strings'').
Comments:
23 pages; final version accepted by EPJC
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2410.13297 [pdf]
EPJC(2025)·7 citations
13
[Submitted on 17 Oct 2024] (cross-list from hep-ph)
Heavy-light Pseudoscalar Mesons: Light-Front Wave Functions and Generalized Parton Distributions
B. Almeida-Zamora🇲🇽 · J.J. Cobos-Martínez🇲🇽 · A. Bashir🇲🇽 · K. Raya🇪🇸 · J. Rodríguez-Quintero🇪🇸 · J. Segovia🇪🇸
The internal structure of the lowest-lying pseudo-scalar mesons with heavy-light quark content is thoroughly studied using an algebraic model that has been successfully applied to similar physical observables of pseudoscalar and vector mesons with hidden-flavor quark content, ranging from light to heavy quark sectors. This model is based on constructing simple and evidence-based ansätze for the mesons' Bethe-Salpeter amplitude (BSA) and quark propagator, allowing the Bethe-Salpeter wave function (BSWF) to be computed algebraically. Its projection onto the light front yields the corresponding light-front wave function (LFWF), which provides easy access to the valence-quark Parton Distribution Amplitude (PDA) by integrating over the transverse momentum squared. We leverage our current knowledge of the PDAs of the lowest-lying pseudo-scalar heavy-light mesons to compute their Generalized Parton Distributions (GPDs) via the overlap representation of the LFWFs. From this three-dimensional information, various limits and projections allow us to deduce the related Parton Distribution Functions (PDFs), Electromagnetic Form Factors (EFFs), and Impact Parameter Space GPDs (IPS-GPDs). Whenever possible, we make explicit comparisons with available experimental results and previous theoretical predictions.
Comments:
Submitted to the proceedings of the 10th International Conference on Quarks and Nuclear Physics (QNP2024), PoS format
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2410.13442 [pdf]
PoS(2025)·1 citation
14
[Submitted on 17 Oct 2024] (cross-list from hep-ph)
Proton internal pressure from deeply virtual Compton scattering on collider kinematics
Hervé Dutrieux🇺🇸 · Thibaud Meisgny🇫🇷 · Cédric Mezrag🇫🇷 · Hervé Moutarde🇫🇷
The unique experimental connection to the QCD energy-momentum tensor offered by generalised parton distributions has been strongly highlighted in the past few years with attempts to extract the pressure and shear forces distributions within the nucleon. If, in principle, this can be performed in a model independent way from experimental data, in practice, the current limited precision and kinematic coverage make such an extraction very challenging. Moreover, the limitation to a leading-order description in the strong coupling of the data has provided only an indirect and weakly sensitive access to gluon degrees of freedoms, solely through their mixing to quarks via evolution. In this paper we address this issue by pro viding a next-to-leading order formalism allowing a reanalysis of global fits with genuine gluonic degrees of freedom. In addition, we provide an estimate of the reduction in uncertainty that could stem from the extended kinematic range relevant for the future Electron Ion Collider. Finally, we stress the connection between the analysis of the dispersion relation in terms of generalised parton distributions and the deconvolution problem.
Comments:
21 pages, 14 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2410.13518 [pdf]
EPJC(2025)·13 citations
15
[Submitted on 17 Oct 2024] (cross-list from hep-ph)
Magnetic moments of $\frac{1}{2}^{-}$ baryon resonances in hot and dense strange hadronic matter
Abhinaba Upadhyay🇮🇳 · Arvind Kumar🇮🇳 · Harleen Dahiya🇮🇳 · Suneel Dutt🇮🇳
This work primarily focusses on determining the magnetic moments of $\frac{1}{2}^{-}$ baryon resonances in the presence of hot and dense hadronic matter. In the chiral $S U (3)$ quark mean field model approach, we have essentially accounted for the effects on in-medium scalar meson fields to investigate the impact of high densities on the in-medium baryon masses and their constituent quarks. In light of chiral constituent quark model $χ$ CQM, we have calculated the magnetic moments of $\frac{1}{2}^{-}$ baryon resonances and scrutinized the effects due to its internal constituents: the valence quarks, sea quarks and the orbital moment of sea quarks. Furthermore, we have investigated the effective baryonic magnetic moments for the finite magnitudes of isospin asymmetry and strangeness fraction.
Comments:
40 pages, 8 tables, 13 figures, Accepted for Publication in PTEP
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2410.13538 [pdf]
PTEP(2025)·0 citations
16
[Submitted on 17 Oct 2024] (cross-list from hep-ph)
Azimuthal modulation in light-by-light scattering from ultraperipheral collisions at LHC
Yu Jia🇨🇳 · Shuo Lin🇨🇳 · Jian Zhou🇨🇳 · Ya-jin Zhou🇨🇳
Elastic light-by-light(LbL) scattering, one of the most fascinating processes in the Standard Model(SM), has recently been observed in the ultraperipheral collisions(UPCs) of relativistic heavy ions in the Atlas and CMS experiments at the Large Hadron Collider LHC. Recognizing that the incident quasi-real photons in LbL scattering are strongly linearly polarized, we re-investigate the LbL scattering in UPCs by incorporating the joint dependence of the impact parameter and transverse momenta of the incident photons. We show that the linear polarization of incident photons generates a sizable $cos 2 ϕ$ -type azimuthal modulation, which awaits the test in future LHC and EIC experiments.
Comments:
8 pages, 1 table, 6 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2410.13781 [pdf]
4 citations
17
[Submitted on 17 Oct 2024] (cross-list from quant-ph)
Observation of string-breaking dynamics in a quantum simulator
Arinjoy De🇺🇸 · Alessio Lerose🇬🇧 · De Luo🇺🇸 · Federica M. Surace🇺🇸 · Alexander Schuckert🇺🇸 · Elizabeth R. Bennewitz🇺🇸 · Brayden Ware🇺🇸 · William Morong🇺🇸 · Kate S. Collins🇺🇸 · Zohreh Davoudi🇺🇸 · Alexey V. Gorshkov🇺🇸 · Or Katz🇺🇸 · Christopher Monroe🇺🇸
Spontaneous particle-pair formation is a fundamental phenomenon in nature. It can, for example, appear when the potential energy between two particles increases with separation, as if they were connected by a tense string. Beyond a critical separation, new particle pairs can form, causing the string to break. String-breaking dynamics in quantum chromodynamics play a vital role in high-energy particle collisions and early universe evolution. Simulating string evolution and hadron formation is, therefore, a grand challenge in modern physics. Quantum simulators, well-suited for studying dynamics, are expected to outperform classical computing methods. However, the required experimental capabilities to simulate string-breaking dynamics have not yet been demonstrated, even for simpler models of the strong force. We experimentally probe, for the first time, the spatiotemporal dynamics of string-breaking in a (1+1)-dimensional $Z_{2}$ lattice gauge theory using a fully programmable trapped-ion quantum simulator. We emulate external static charges and strings via site-dependent magnetic-field control enabled by a dual array of tightly focused laser beams targeting individual ions. First, we study how confinement affects isolated charges, finding that they freely spread without string tension but exhibit localized oscillations when tension is increased. Then, we observe and characterize string-breaking dynamics of a string stretched between two static charges after an abrupt increase in string tension. Charge pairs appear near the string edges and spread into the bulk, revealing a route to dynamical string-breaking distinct from the conventional Schwinger mechanism. Our work demonstrates that analog quantum simulators have achieved the necessary control to explore string-breaking dynamics, which may ultimately be relevant to nuclear and high-energy physics.
Comments:
22 pages, 3 main figures, 9 extended data figures
Subjects:
Quantum Physics (quant-ph); Quantum Gases (cond-mat.quant-gas); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2410.13815 [pdf]
100 citations

Affiliations

first authorsco-authorsvia INSPIRE