Nuclear Theory·nucl-th

Tuesday·July 18, 2023

19 papers—4 primary·15 cross-listed

05
[Submitted on 13 Jul 2023] (cross-list from hep-th)
Emergent symmetries of relativistic fluid dynamics from local ergodicity
Giorgio Torrieri🇧🇷
We show that volume-preserving diffomorphisms and the chemical shift symmetry defining relativistic lagrangian ideal fluid dynamics can be derived as an emerging symmetry when ergodicity is assumed to apply locally in a way that is invariant under smooth spacetime foliations. This can be used as a way to derive the ideal hydrodynamic limit in a strongly coupled but strongly fluctuating medium. We comment on the connection with thermalization in small systems, the Eigenstate thermalization hypothesis and deviations from the ideal limit.
Comments:
Accepted for publication, Phys.Rev.D
Subjects:
High Energy Physics — Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2307.07021 [pdf]
PRD(2024)·15 citations
06
[Submitted on 13 Jul 2023] (cross-list from hep-ph)
PRyMordial: The First Three Minutes, Within and Beyond the Standard Model
Anne-Katherine Burns🇺🇸 · Tim M.P. Tait🇺🇸 · Mauro Valli🇺🇸
In this work we present PRyMordial: A package dedicated to efficient computations of observables in the Early Universe with the focus on the cosmological era of Big Bang Nucleosynthesis (BBN). The code offers fast and precise evaluation of BBN light-element abundances together with the effective number of relativistic degrees of freedom, including non-instantaneous decoupling effects. PRyMordial is suitable for state-of-the-art analyses in the Standard Model as well as for general investigations into New Physics active during BBN. After reviewing the physics implemented in PRyMordial, we provide a short guide on how to use the code for applications in the Standard Model and beyond. The package is written in Python, but more advanced users can optionally take advantage of the open-source community for Julia. PRyMordial is publicly available on GitHub.
Comments:
33 pages, 5 figures, 2 tables; comments are welcome; code at https://github.com/vallima/PRyMordial v2: A few refs added, typos corrected, examples updated according to most recent version of PRyMordial
Subjects:
High Energy Physics — Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Nuclear Theory (nucl-th)
arXiv:
2307.07061 [pdf]
EPJC(2024)·85 citations
07
[Submitted on 13 Jul 2023] (cross-list from nucl-ex)
Level Structures of $^{56, 58}$ Ca Cast Doubt on a doubly magic $^{60}$ Ca
S. Chen🇨🇳 · F. Browne🇯🇵 · P. Doornenbal🇯🇵 · J. Lee🇨🇳 · A. Obertelli🇩🇪 · Y. Tsunoda🇯🇵 · T. Otsuka🇯🇵 · Y. Chazono🇯🇵 · G. Hagen🇺🇸 · J.D. Holt🇨🇦 · G.R. Jansen🇺🇸 · K. Ogata🇯🇵 and 71 other authors
Gamma decays were observed in $^{56}$ Ca and $^{58}$ Ca following quasi-free one-proton knockout reactions from $^{57, 59}$ Sc beams at $\approx 200$ MeV/nucleon. For $^{56}$ Ca, a $γ$ ray transition was measured to be 1456(12) keV, while for $^{58}$ Ca an indication for a transition was observed at 1115(34) keV. Both transitions were tentatively assigned as the $2_{1}^{+} \to 0_{g s}^{+}$ decays, and were compared to results from ab initio and conventional shell-model approaches. A shell-model calculation in a wide model space with a marginally modified effective nucleon-nucleon interaction depicts excellent agreement with experiment for $2_{1}^{+}$ level energies, two-neutron separation energies, and reaction cross sections, corroborating the formation of a new nuclear shell above the $N$ = 34 shell. Its constituents, the $0 f_{5/2}$ and $0 g_{9/2}$ orbitals, are almost degenerate. This degeneracy precludes the possibility for a doubly magic $^{60}$ Ca and potentially drives the dripline of Ca isotopes to $^{70}$ Ca or even beyond.
Comments:
8 pages, 3 figures
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2307.07077 [pdf]
PLB(2023)·21 citations
08
[Submitted on 14 Jul 2023] (cross-list from nucl-ex)
Nuclear Level Density and $γ$ -ray Strength Function of $^{67} Ni$ and the impact on the i-process
V. W. Ingeberg🇳🇴 · S. Siem🇳🇴 · M. Wiedeking🇺🇸 · A. Choplin🇧🇪 · S. Goriely🇧🇪 · L. Siess🇧🇪 · K. J. Abrahams🇿🇦 · K. Arnswald🇩🇪 · F. Bello Garrote🇳🇴 · D. L. Bleuel🇺🇸 · J. Cederkäll · T. L. Christoffersen🇳🇴 and 20 other authors
Proton- $γ$ coincidences from $(d, p)$ reactions between a $^{66} Ni$ beam and a deuterated polyethylene target have been analyzed with the inverse-Oslo method to find the nuclear level density (NLD) and $γ$ -ray strength function ( $γ$ SF) of $^{67} Ni$ . The $^{66} Ni (n, γ)$ capture cross section has been calculated using the Hauser-Feshbach model in TALYS using the measured NLD and $γ$ SF as constraints. The results confirm that the $^{66} Ni (n, γ)$ reaction acts as a bottleneck when relying on one-zone nucleosynthesis calculations. However, the impact of this reaction is strongly dampened in multi-zone models of low-metallicity AGB stars experiencing i-process nucleosynthesis.
Comments:
Submitted to Phys. Rev. C
Subjects:
Nuclear Experiment (nucl-ex); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Theory (nucl-th)
arXiv:
2307.07153 [pdf]
PRC(2025)·9 citations
09
[Submitted on 14 Jul 2023] (cross-list from quant-ph)
Nuclear Physics in the Era of Quantum Computing and Quantum Machine Learning
J.E. García-Ramos🇪🇸 · A. Sáiz🇪🇸 · J.M. Arias🇪🇸 · L. Lamata🇪🇸 · P. Pérez-Fernández🇪🇸
In this paper, the application of quantum simulations and quantum machine learning to solve low-energy nuclear physics problems is explored. The use of quantum computing to deal with nuclear physics problems is, in general, in its infancy and, in particular, the use of quantum machine learning in the realm of nuclear physics at low energy is almost nonexistent. We present here three specific examples where the use of quantum computing and quantum machine learning provides, or could provide in the future, a possible computational advantage: i) the determination of the phase/shape in schematic nuclear models, ii) the calculation of the ground state energy of a nuclear shell model-type Hamiltonian and iii) the identification of particles or the determination of trajectories in nuclear physics experiments.
Comments:
Submitted to the special issue "Quantum Machine Learning" of the journal Advanced Quantum Technologies
Subjects:
Quantum Physics (quant-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2307.07332 [pdf]
Adv.Quantum Technol.(2025)·19 citations
10
[Submitted on 14 Jul 2023] (cross-list from hep-ph)
Photon and dilepton emission anisotropy for a magnetized quark-gluon plasma
Xinyang Wang🇨🇳 · Igor A. Shovkovy🇺🇸
We study the higher-order anisotropy coefficients $v_{4}$ and $v_{6}$ in the photon and dilepton emission from a hot magnetized quark-gluon plasma. Together with the earlier predictions for $v_{2}$ , these results show a distinctive pattern of the anisotropy coefficients in several kinematic regimes. In the case of photon emission, nonzero coefficients $v_{n}$ (with even $n$ ) have opposite signs at small and large values of the transverse momentum (i.e., $k_{T} ≲ ∣ e B ∣$ and $k_{T} ≳ ∣ e B ∣$ , respectively). Additionally, the $v_{n}$ signs alternate with increasing $n$ , and their approximate values decrease as $1/ n^{2}$ in magnitude. The anisotropy of dilepton emission is well pronounced only at large transverse momenta and small invariant masses (i.e., when $k_{T} ≳ ∣ e B ∣$ and $M ≲ ∣ e B ∣$ ). The corresponding $v_{4}$ and $v_{6}$ coefficients are of the same magnitude and show a similar alternating sign pattern with increasing $n$ as in the photon emission.
Comments:
12 pages, 6 multi-panel figures, final version published in Physical Review D
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2307.07557 [pdf]
PRD(2024)·12 citations
11
[Submitted on 15 Jul 2023] (cross-list from hep-ph)
Studying QGP transport properties in a concurrent minijet+hydro framework
Charles Gale🇨🇦 · Sangyong Jeon🇨🇦 · Daniel Pablos🇪🇸 · Mayank Singh🇺🇸
Minijets are ubiquitous in heavy-ion collision experiments. However, they are often excluded from the hydrodynamic simulations of QGP as they do not thermalize at short time scales and are not treated as part of the collective medium. Using a concurrent jet+hydro framework, we show that the minijets could account for a significant portion of particle multiplicity. Therefore, the energy deposition from minijet-medium interactions can substantially modify the QGP transport properties inferred from model-to-data comparisons.
Comments:
6 pages, 4 figures, Proceedings for Hard Probes 2023
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2307.07844 [pdf]
PoS(2024)·0 citations
12
[Submitted on 15 Jul 2023] (cross-list from hep-ph)
Comparative multi-probe study of jet energy-loss in QGP
Rouzbeh Modarresi Yazdi🇨🇦 · Shuzhe Shi🇺🇸 · Charles Gale🇨🇦 · Sangyong Jeon🇨🇦
Jet-energy loss is an important sign of the creation of Quark-Gluon Plasma in heavy-ion collisions. High transverse momentum ( $p_{T}$ ) partons are produced at the moment of initial hard scattering and are modified as a result of their propagation through the created medium. We study two models of low-virtuality radiative energy loss: CUJET and MARTINI. This is done using the JETSCAPE framework, which allows for an objective comparison. CUJET is integrated into the JETSCAPE workflow, and full jet simulations, including substructure observables, are computed for the first time using leading-order DGLV rates. Strongly-interacting probes (charged hadrons, jets, jet fragmentation functions and jet shape ratio) are considered along jet-medium photons for the first time in a dynamic QGP. We find that these photons make a significant contribution in the phenomenologically interesting intermediate $p_{T}$ domain of $4$ - $12$ GeV.
Comments:
Presented at the 11th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions (Hard Probes 2023)
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2307.07890 [pdf]
PoS(2024)·1 citation
13
[Submitted on 16 Jul 2023] (cross-list from nucl-ex)
Understanding the total width of the $3_{1}^{-}$ state in $^{12} C$
K. C. W. Li · R. Neveling · P. Adsley · H. Fujita · P. Papka · F. D. Smit · J. W. Brümmer · L. M. Donaldson · M. N. Harakeh · Tz. Kokalova · E. Nikolskii · W. Paulsen and 3 other authors
Recent measurements indicate that the previously established upper limit for the $γ$ -decay branch of the $3_{1}^{-}$ resonance in $^{12} C$ at $E_{x} = 9.641 (5)$ MeV may be incorrect. As a result, the $3_{1}^{-}$ resonance has been suggested as a significant resonance for mediating the triple- $α$ reaction at high temperatures above 2 GK. Accurate estimations of the $3_{1}^{-}$ contribution to the triple- $α$ reaction rate require accurate knowledge of not only the radiative width, but also the total width. In anticipation of future measurements to more accurately determine the $γ$ -decay branch of the $3_{1}^{-}$ resonance, the objective of this work is to accurately determine the total width of the $3_{1}^{-}$ resonance. An evaluation was performed on all previous results considered in the current ENSDF average of 46(3) keV for the physical total width (FWHM) of the $3_{1}^{-}$ resonance in $^{12} C$ . Significant unaccounted-for uncertainties and a misstated result were discovered in these previous results, leading to an invalid ENSDF average. In this work, the new global \textbf{R}-matrix analysis performed on direct-reaction data yields a formal total width of $Γ (E_{r}) = 46 (2)$ keV and an observed total width of $Γ_{obs} (E_{r}) = 38 (2)$ keV for the $3_{1}^{-}$ resonance. An observed total width of $Γ_{obs} (E_{r}) = 38 (2)$ keV is recommended for the $3_{1}^{-}$ resonance in $^{12} C$ . This observed total width should be employed for future evaluations of the observed total radiative width for the $3_{1}^{-}$ resonance and its contribution to the high-temperature triple- $α$ reaction rate.
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2307.07917 [pdf]
PRC(2024)·3 citations
14
[Submitted on 16 Jul 2023] (cross-list from hep-ph)
Heavy quark $κ$ and jet $q^$ transport coefficients in the Glasma early stage of heavy-ion collisions
Dana Avramescu🇫🇮 · Virgil Băran🇷🇴 · Vincenzo Greco🇮🇹 · Andreas Ipp🇦🇹 · David. I. Müller🇦🇹 · Marco Ruggieri🇮🇹
We study the impact of the Glasma fields, used to describe the very early stage of heavy-ion collisions, on the transport of hard probes, namely heavy quarks and jets. We perform numerical simulations of the strong classical fields using techniques from real-time lattice gauge theory. The resulting fields are used as background for the classical transport of ensembles of particles, described by Wong's equations. For this purpose, we develop a numerical solver for the transport of the probes, based on colored particle-in-cell methods. We focus on the dynamics of heavy quarks and jets in the classical colored fields. To quantify the effect of the Glasma, we extract the momentum broadening of hard probes and evaluate the anisotropy transfer from the Glasma to the probes. Lastly, we evaluate the heavy quark $κ$ and jet $q^$ transport coefficients in the Glasma, which turn out to be large and exhibit a peak, irrespective of the particle initialization.
Comments:
7 pages, 2 figures, proceedings for the 11th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions (Hard Probes 2023)
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2307.07999 [pdf]
PoS(2024)·4 citations
15
[Submitted on 16 Jul 2023] (cross-list from hep-ph)
Effects of multi-scale jet-medium interactions on jet substructures
JETSCAPE Collaboration: Y. Tachibana · A. Angerami · R. Arora · S. A. Bass · S. Cao · Y. Chen · T. Dai · L. Du · R. Ehlers · H. Elfner · W. Fan · R. J. Fries and 47 other authors
We utilize event-by-event Monte Carlo simulations within the JETSCAPE framework to examine scale-dependent jet-medium interactions in heavy-ion collisions. The reduction in jet-medium interaction during the early high-virtuality stage, where the medium is resolved at a short distance scale, is emphasized as a key element in explaining multiple jet observables, particularly substructures, simultaneously. By employing the MATTER+LBT setup, which incorporates this explicit reduction of medium effects at high virtuality, we investigate jet substructure observables, such as Soft Drop groomed observables. When contrasted with existing data, our findings spotlight the significant influence of the reduction at the early high-virtuality stages. Furthermore, we study the substructure of gamma-tagged jets, providing predictive insights for future experimental analyses. This broadens our understanding of the various contributing factors involved in modifying jet substructures.
Comments:
6 pages, 4 figures, contribution to the Hard Probes 2023 proceedings
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2307.08125 [pdf]
PoS(2024)·0 citations
16
[Submitted on 17 Jul 2023] (cross-list from hep-ph)
System size dependence of pre-equilibrium and applicability of hydrodynamics in heavy-ion collisions
Victor E. Ambruş🇵🇱 · Sören Schlichting🇷🇴 · Clemens Werthmann🇩🇪
We simulate the space-time dynamics of high-energy collisions based on a microscopic kinetic description, in order to determine the range of applicability of an effective description in relativistic viscous hydrodynamics. We find that hydrodynamics provides a quantitatively accurate description of collective flow when the average inverse Reynolds number $Re^{- 1}$ is sufficiently small and the early pre-equilibrium stage is properly accounted for. By determining the breakdown of hydrodynamics as a function of system size and energy, we find that it is quantitatively accurate in central lead-lead collisions at LHC energies, but should not be used in typical proton-lead or proton-proton collisions, where the development of collective flow can not accurately be described within hydrodynamics.
Comments:
6 pages, 4 figures. Contribution to the HardProbes2023 conference proceedings
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2307.08306 [pdf]
PoS(2024)·4 citations
17
[Submitted on 17 Jul 2023] (cross-list from hep-ph)
Longitudinal flow decorrelation in heavy-ion collision at RHIC energies using a multi-phase transport model
Prabhupada Dixit · Md. Nasim
We present a study on the longitudinal flow decorrelation in heavy-ion collisions at the RHIC Beam Energy Scan (BES) energies ( $s_{N N}$ = 11.5 to 200 GeV in Au+Au collisions) using the AMPT model. We measure the second and third order factorization ratios ( $r_{2}$ and $r_{3}$ ) across BES energies, finding $r_{2}$ weakly dependent on collision energy while $r_{3}$ shows a more prominent collision energy dependent. The effect of parton-parton scattering cross section on $r_{2}$ and $r_{3}$ is studied which suggests that longitudinal decorrelation could be a potential observable to constrain transport properties of the medium. We also analyze the contributions of flow-plane and flow magnitude decorrelation, with flow-plane decorrelation being dominant. we measure a recently proposed observable, the four particle cumulant ( $T_{2}$ ), which remains resilient to non-flow effects and exhibits sensitivity to different decorrelation patterns. Through the measurement of $T_{2}$ , we consistently observe a hint of S-shaped or torqued decorrelation across all energy ranges in peripheral collisions (40-80\%). But in central and mid-central collisions, presence of any specific pattern of decorrelation is missing in AMPT model.
Comments:
8 pages, 8 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2307.08406 [pdf]
2 citations
18
[Submitted on 17 Jul 2023] (cross-list from physics.acc-ph)
Artificial Intelligence for the Electron Ion Collider (AI4EIC)
C. Allaire · R. Ammendola · E.-C. Aschenauer · M. Balandat · M. Battaglieri · J. Bernauer · M. Bondì · N. Branson · T. Britton · A. Butter · I. Chahrour · P. Chatagnon and 84 other authors
The Electron-Ion Collider (EIC), a state-of-the-art facility for studying the strong force, is expected to begin commissioning its first experiments in 2028. This is an opportune time for artificial intelligence (AI) to be included from the start at this facility and in all phases that lead up to the experiments. The second annual workshop organized by the AI4EIC working group, which recently took place, centered on exploring all current and prospective application areas of AI for the EIC. This workshop is not only beneficial for the EIC, but also provides valuable insights for the newly established ePIC collaboration at EIC. This paper summarizes the different activities and R&D projects covered across the sessions of the workshop and provides an overview of the goals, approaches and strategies regarding AI/ML in the EIC community, as well as cutting-edge techniques currently studied in other experiments.
Comments:
27 pages, 11 figures, AI4EIC workshop, tutorials and hackathon
Subjects:
Accelerator Physics (physics.acc-ph); Machine Learning (cs.LG); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2307.08593 [pdf]
Comput.Softw.Big Sci.(2024)·30 citations
19
[Submitted on 17 Jul 2023] (cross-list from hep-lat)
Magnetic polarizability of a charged pion from four-point functions in lattice QCD
Frank X. Lee🇺🇸 · Walter Wilcox🇺🇸 · Andrei Alexandru🇺🇸 · Chris Culver🇬🇧
Electromagnetic dipole polarizabilities are fundamental properties of a hadron that represent its resistance to deformation under external fields. For a charged hadron, the presence of acceleration and Landau levels complicates the isolation of its deformation energy in the conventional background field method. In this work, we explore a general method based on four-point functions in lattice QCD that takes into account all photon, quark and gluon interactions. The electric polarizability ( $α_{E}$ ) has been determined from the method in a previous proof-of-principle simulation. Here we focus on the magnetic polarizability ( $β_{M}$ ) using the same quenched Wilson action on a $2 4^{3} \times 48$ lattice at $β = 6.0$ with pion mass from 1100 to 370 MeV. The results from the connected diagrams show a large cancellation between the elastic and inelastic contributions, leading to a relatively small and negative value for $β_{M}$ consistent with chiral perturbation theory. We also discuss the mechanism for $α_{E} + β_{M}$ from combining the two studies.
Comments:
11 pages, 8 figures, 1 table. Version accepted for publication in PRD. arXiv admin note: substantial text overlap with arXiv:2301.05200
Subjects:
High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2307.08620 [pdf]
PRD(2023)·11 citations

Affiliations

first authorsco-authorsvia INSPIRE