Nuclear Theory·nucl-th

Wednesday·August 21, 2024

11 papers—2 primary·9 cross-listed

03
The $ρ$ meson magnetic dipole moment from BaBar $e^{+} e^{-} \to π^{+} π^{-} π^{0} π^{0}$ cross section measurement
Antonio Rojas🇲🇽 · Genaro Toledo🇲🇽
We obtain the value of the magnetic dipole moment of the $ρ$ meson, using data from the BaBar Collaboration for the $e^{+} e^{-} \to π^{+} π^{-} 2 π^{0}$ process. The considered center of mass energy range is from 0.9 to 1.8 GeV. We describe the $γ^{*} \to 4 π$ vertex using a vector meson dominance model, including the intermediate resonant contributions relevant at these energies. We find $μ_{ρ} = 2.7 \pm 0.3$ in $e /2 m_{ρ}$ units. We improve on the previous extracted value, where preliminary data from the same collaboration was used, by considering definite data, better grounded values of the parameters involved and explicit gauge invariant description of the process.
↳ hep-phhep-exnucl-thPRD(2024)·7 citations
04
Kilonova Emissions from Neutron Star Merger Remnants: Implications for Nuclear Equation of State
Kelsey A. Lund · Rahul Somasundaram · Gail C. McLaughlin · Jonah M. Miller · Matthew R. Mumpower · Ingo Tews
Multi-messenger observation of binary neutron-star mergers can provide valuable information on the nuclear equation of state (EoS). Here, we investigate to which extent electromagnetic observations of the associated kilonovae allow us to place constraints on the EoS. For this, we use state-of-the-art three-dimensional general-relativistic magneto-hydrodynamics simulations and detailed nucleosynthesis modeling to connect properties of observed light curves to properties of the accretion disk, and hence, the EoS. Using our general approach, we use multi-messenger observations of GW170817/AT2017gfo to study the impact of various sources of uncertainty on inferences of the EoS. We constrain the radius of a $1.4 M_{⊙}$ neutron star to lie within $10.19 \leq R_{1.4} \leq 13.0$ ~km and the maximum mass to be $M_{TOV} \leq 3.06 M_{⊙}$ .
↳ astro-ph.HEnucl-th5 citations
05
Effective range expansion with a long-range force
Meng-Lin Du🇨🇳 · Feng-Kun Guo🇨🇳 · Bing Wu🇨🇳
The validity range of the time-honored effective range expansion can be very limited due to the presence of a left-hand cut close to the two-particle threshold. Such a left-hand cut arises in the two-particle interaction involving a light particle exchange with a mass small or slightly heavier than the mass difference of the two particles, identified as a long-range force, a scenario encountered in a broad range of systems. This can hinder a precise extraction of low-energy scattering observables and resonance poles. To address this issue, we propose a new parameterization for the low-energy scattering amplitude that accounts for the left-hand cut. The parameterization is like a Padé approximation but with nonanalytic terms from the left-hand cut and can be regarded as an extension of the effective range expansion. This parameterization is versatile and applicable to a broad range of systems with Yukawa-type interactions -- including particle, hadronic, nuclear, cold atom and quantum gas systems. In particular, it should be invaluable in understanding various near-threshold hadron resonances. As byproducts, we also show that the parameterization can be used to extract the couplings of the exchanged particle to the scattering particles, and derive expressions for amplitude zeros caused by the interplay between the short- and long-range interactions.
↳ hep-phcond-mat.quant-gashep-latnucl-thPRL(2025)·13 citations
06
Electron-nucleus cross sections from transfer learning
Krzysztof M. Graczyk🇵🇱 · Beata E. Kowal🇵🇱 · Artur M. Ankowski🇵🇱 · Rwik Dharmapal Banerjee🇵🇱 · Jose Luis Bonilla🇵🇱 · Hemant Prasad🇵🇱 · Jan T. Sobczyk🇵🇱
Transfer learning (TL) allows a deep neural network (DNN) trained on one type of data to be adapted for new problems with limited information. We propose to use the TL technique in physics. The DNN learns the details of one process, and after fine-tuning, it makes predictions for related processes. We consider the DNNs, trained on inclusive electron-carbon scattering data, and show that after fine-tuning, they accurately predict cross sections for electron interactions with nuclear targets ranging from helium-3 to iron.
↳ hep-phcs.LGhep-exnucl-ex+1PRL(2025)·7 citations
07
Signature of hadron-quark crossover in binary-neutron-star mergers
Yuki Fujimoto🇺🇸 · Kenji Fukushima🇯🇵 · Kenta Hotokezaka🇯🇵 · Koutarou Kyutoku🇯🇵
We study observational signatures of the hadron-quark crossover in binary-neutron-star mergers by numerical-relativity simulations with various mass configurations. We employ two equations of state (EoSs) for matter consistent with inference from the observational data. In the crossover scenario the EoS is softened in a density realized in binary-neutron-star mergers and is smoothly continued to quark matter. In the phase transition scenario without crossover, the EoS remains stiff and a first-order phase transition takes place in a density out of reach of mergers. A GW170817-like system forms a remnant massive neutron star in both scenarios, and it collapses into a black hole only in the crossover scenario due to the softening while gravitational-wave emission is strong. This difference is clearly reflected in the sudden shutdown of gravitational waves. For a given EoS, the lifetime of the merger remnant is determined primarily by the total mass of the system. Identifying these features in a variety of future events with the next generation of ground-based gravitational-wave detectors will enable us to clarify details of hadron-quark transition. The mass of the accretion disk surrounding the remnant black hole is affected not only by the lifetime of the remnant but also by the mass ratio of the system. Electromagnetic emission associated with the disk outflow will also be useful for detailed investigation of the hadron-quark transition.
↳ astro-ph.HEgr-qcnucl-thPRD(2025)·20 citations
08
Observation of the Symmetry-Protected Signature of 3-body Interactions
Liudmila A. Zhukas🇺🇸 · Qingfeng Wang🇺🇸 · Or Katz🇺🇸 · Christopher Monroe🇺🇸 · Iman Marvian🇺🇸
Identifying and characterizing multi-body interactions in quantum processes remains a significant challenge. This is partly because 2-body interactions can produce an arbitrary time evolution, a fundamental fact often called the universality of 2-local gates in the context of quantum computing. However, when an unknown Hamiltonian respects a U(1) symmetry such as charge or particle number conservation, N-body interactions exhibit a distinct symmetry-protected signature known as the N-body phase, which fewer-body interactions cannot mimic. We develop and demonstrate an efficient technique for the detection of 3-body interactions despite the presence of unknown 2-body interactions. This technique, which takes advantage of GHZ states for phase estimation, requires probing the unitary evolution and measuring its determinant in a small subspace that scales linearly with the system size, making it an efficient approach.
↳ quant-phcond-mat.str-elhep-thmath-ph+23 citations
09
A note on the canonical approach to hydrodynamics and linear response theory
Luca Martinoia🇮🇹 · Rajeev Singh🇺🇸
This note provides a comprehensive examination of the various approaches to formulating relativistic hydrodynamics, with a particular emphasis on the canonical approach. Relativistic hydrodynamics plays a crucial role in understanding the behavior of fluids in high-energy astrophysical phenomena and heavy-ion collisions. The canonical approach is explored in detail, highlighting its foundational principles, mathematical formulations, and practical implications in modeling relativistic fluid dynamics. Following this, we delve into the linear response theory, elucidating its relevance in the context of hydrodynamics. We analyze the response of relativistic fluids to external perturbations, discussing the theoretical framework and key results. This dual focus aims to bridge the gap between theoretical foundations and practical applications, offering a robust perspective on the dynamic interplay between relativistic hydrodynamics and linear response theory.
↳ hep-thcond-mat.str-elnucl-thActa Phys.Polon.B(2025)·2 citations
10
Unveiling the jet angular broadening with photon-tagged jets in high-energy nuclear collisions
Sa Wang🇨🇳 · Yao Li🇨🇳 · Jin-Wen Kang🇨🇳 · Ben-Wei Zhang🇨🇳
The medium modification of jet substructure in hot and dense nuclear matter has garnered significant interest from the heavy-ion physics community in recent years. Measurements of inclusive jets show an angular narrowing in nucleus-nucleus collisions, while recent CMS results for photon-tagged jets ( $γ$ +jets) suggest evidence of broadening. In this study, we conduct a theoretical analysis of the angular structure of inclusive jets and $γ$ +jets using a transport approach that accounts for jet energy loss and the medium response in the quark-gluon plasma. We examine the girth modification of $γ$ +jets in $0 - 30%$ PbPb collisions at $s_{N N} = 5.02$ TeV, achieving satisfactory agreement with recent CMS measurements. We explore the relationship between selection bias and jet kinematics by varying the threshold for $x_{j γ} = p_{T}^{jet} / p_{T}^{γ}$ . Notably, we quantitatively demonstrate that $γ$ +jets significantly reduce selection bias and can effectively select jets that have been sufficiently quenched in PbPb collisions, which is crucial for capture the jet angular broadening. Additionally, we estimate the contributions of medium-induced gluon radiation and the medium response to the broadening of the jet angular substructure. Lastly, we analyze the modification patterns of jet $R_{g}$ and $Δ R_{axis}$ in PbPb collisions, which indicate slight broadening for $γ$ +jets and noticeable narrowing for inclusive jets compared to pp collisions.
↳ hep-phnucl-thNucl.Sci.Tech.(2026)·6 citations
11
Lambda transverse polarization in NA61\SHINE at the CERN SPS: feasibility studies
Yehor Bondar🇵🇱 · Wojciech Florkowski🇵🇱
The spin polarization of $Λ$ hyperons produced in inclusive reactions with unpolarized protons on unpolarized targets has been studied for almost 40 years. The NA61\SHINE experiment at the CERN SPS has a great potential to study transverse polarization in p-p and p-A collisions. In this work, we discuss the impact of magnetic field and limited detector acceptance on the possible polarization measurement by this experiment. Our analysis shows that the magnetic field impact on the $Λ$ polarization due to precession is one order of magnitude smaller than the detector acceptance-based polarization bias, and the identification of an experimental signal similar to that observed before by other experiments is possible.
↳ hep-phnucl-exnucl-thActa Phys.Polon.B(2024)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE