Nuclear Theory·nucl-th

Friday·April 12, 2024

8 papers—3 primary·5 cross-listed

01
Multifractal Dimension Spectrum Analysis for Nuclear Density Distribution
Weihu Ma · Yu-Gang Ma · Wanbing He · Bo Zhou
We present an integral density method for calculating the multifractal dimension spectrum for the nucleon distribution in atomic nuclei. This method is then applied to analyze the non-uniformity of the density distribution in several typical types of nuclear matter distributions, including the Woods-Saxon distribution, the halo structure and the tetrahedral $α$ clustering. The subsequent discussion provides a comprehensive and detailed exploration of the results obtained. The multifractal dimension spectrum shows remarkable sensitivity to the density distribution, establishing it as an effective tool for studying the distribution of nucleons in nuclear multibody systems.
nucl-thnucl-exChaos(2024)·3 citations
02
A new scheme for isomer pumping and depletion with high-power lasers
C.-J. Yang · K. M. Spohr · M. Cernaianu · D. Doria · P. Ghenuche · V. Horny
We propose a novel scheme for the population and depletion of nuclear isomers. The scheme combines the $γ$ -photons with energies $≳ 10$ keV emitted during the interaction of a contemporary high-intensity laser pulse with a plasma and one or multiple photon beams supplied by intense lasers. Due to nonlinear effects, two- or multi-photon absorption dominates over the conventional multi-step one-photon process for an optimized gamma flash. Moreover, this nonlinear effect can be greatly enhanced with the help of externally supplied low-energy photons coming from another laser. These low-energy photons act such that the effective cross-section experienced by the $γ$ -photons becomes tunable, growing with the intensity $I_{0}$ of the beam. Assuming $I_{0} \sim 1 0^{18}$ Wcm $^{- 2}$ for the photon beam, an effective cross-section as large as $1 0^{- 21}$ cm $^{2}$ to $1 0^{- 28}$ cm $^{2}$ for the $γ -$ photon can be achieved. Thus, within state-of-the-art 10 PW laser facilities, the yields from two-photon absorption can reach $1 0^{6}$ to $1 0^{9}$ isomers per shot for selected states that are separated from their ground state by E2 transitions. Similar yields for transitions with higher multipolarities can be accommodated by multi-photon absorption with additional photons provided.
nucl-thnucl-exMatter Radiat.Extremes(2025)·6 citations
03
Astrophysics and Nuclear Physics Informed Interactions in Dense Matter: Inclusion of PSR J0437-4715
Tuhin Malik🇵🇹 · Veronica Dexheimer🇺🇸 · Constança Providência🇵🇹
We investigate how vector-isoscalar and vector-isovector interactions can be determined within the density regime of neutron stars (NSs), while fulfilling nuclear and astrophysics constrains. We make use of the Chiral Mean Field (CMF) model, a SU(3) nonlinear realization of the sigma model within the mean-field approximation, for the first time within a Bayesian analysis framework. We show that neutron-matter $χ$ EFT constraints at low density are only satisfied if the vector-isovector mixed interaction term is included, e.g., a $ω^{2} ρ^{2}$ term. We also show the behavior of the model with respect to the conformal limit. We demonstrate that the CMF model is able to predict a value for the parameter $d_{c}$ related to the trace anomaly and its derivative takes values below 0.2 above four times saturation density within a hadronic version of the model that does not include hyperons or a phase transition to deconfined matter. We compare these effects with results from other (non-chiral) Relativistic Mean Field models to assess how different approaches to incorporating the same physical constraints affect predictions of NS properties and dense matter equations of state. We also include data from the gravitation wave event GW230529 detected by the LIGO-Virgo-Kagra collaboration and the most recent radius measurement of PSR J0437-4715 from the NASA NICER mission. Our analysis reveals that this new NICER measurement leads to an average reduction of approximately $\sim 0.1$ km radius in the posterior of the NS mass-radius relationship.
nucl-thastro-ph.HEgr-qchep-phPRD(2024)·31 citations
04
Light-by-light scattering in ultraperipheral collisions of heavy ions with future FoCal and ALICE 3 detectors
Antoni Szczurek🇵🇱
I present possible future studies of light-by-light scattering using FoCal@ALICE and ALICE 3 detectors. Different mechanisms are discussed. The PbPb $\to$ PbPb $γ γ$ cross section is calculated within equivalent photon approximation in the impact parameter space. Several differential distributions are presented and discussed. We predict cross section in the (mb-b) range for typical ALICE 3 cuts, a few orders of magnitude larger than for the current ATLAS or CMS experiments. We also consider the two- $π^{0}$ background which can, in principle, be eliminated at the new kinematical range for the ALICE 3 measurements by imposing dedicated cuts on diphoton transverse momentum and $\slash$ or so-called vector asymmetry.
↳ hep-phnucl-thPhys.Proc.UPC(2024)·0 citations
05
Neutral-current background induced by atmospheric neutrinos at large liquid-scintillator detectors: III. Comprehensive prediction for low energy neutrinos
Jie Cheng🇨🇳 · Min Li🇨🇳 · Yu-Feng Li🇨🇳 · Gao-Song Li🇨🇳 · Hao-Qi Lu🇨🇳 · Liang-Jian Wen🇨🇳
Atmospheric neutrinos play a vital role in generating irreducible backgrounds in liquid-scintillator (LS) detectors via their neutral-current (NC) interactions with $^{12}$ C nuclei. These interactions may affect a wide range of research areas from the MeV to GeV energy range, such as the reactor and geo neutrinos, diffuse supernova neutrino background (DSNB), dark matter, and nucleon decay searches. In this work, we extend our preceding paper, by conducting a first-time systematic exploration of NC backgrounds as low as the MeV region of reactor and geo neutrinos. We utilize up-to-date neutrino generator models from GENIE and NuWro, a TALYS-based nuclear deexcitation package and a GEANT4-based detector simulation toolkit for our complete calculation. Our primary focus is to predict the NC background for experimental searches of inverse-beta-decay signals below the 100 MeV visible energy. In order to have deeper understanding of the characteristics of atmospheric neutrino NC interactions in LS, we investigate the model dependence of NC background predictions by using various data-driven models, including the initial neutrino-nucleon interactions, nuclear ground-state structure, final-state interactions, nuclear deexcitation processes, and secondary interactions of final-state particles.
↳ hep-phhep-exnucl-thEPJC(2025)·5 citations
06
Baryon junction effects on charmonium production in pp and pPb collisions
R. Terra
In this work we study the effects of the proton and $P b$ internal structure on charmonium production at high multiplicities. To do this, we assume that the nucleon has an Y shape, which means that the effective quarks (quarks + antiquarks + gluons) are in the extremities of the Y, connected by gluon lines. Since the quarks are in the periphery and the gluons are in the center, as $pp$ collisions go from peripheral to more central and then to ultra-central collisions, the interactions change from quark-quark to gluon-gluon. The enhanced growth of $J / ψ$ occurs because $σ (g + g \to c + c ˉ) ≫ σ (q + q ˉ \to c + c ˉ)$ . In the $p - P b$ collisions the enhancement is caused by the high concentration of partons in the center of the nuclei. These effects can explain the growth seen in the data and give support to the Y picture of the proton.
↳ hep-phnucl-th1 citation
07
Flavor asymmetry from the non-perturbative nucleon sea
Yihan Duan🇨🇳 · Siqi Xu🇨🇳 · Shan Cheng🇨🇳 · Xingbo Zhao🇨🇳 · Yang Li🇨🇳 · James P. Vary🇺🇸
We demonstrate, in the context of a scalar version of the chiral effective field theory, that the multi-sea quark contribution to the nucleon is significant and highly non-trivial in sharp contrast to the prediction of perturbation theory. The non-perturbative calculation is performed in the Fock sector dependent renormalization scheme on the light front, in which the non-perturbative renormalization is incorporated. The calculation suggests that a fully non-perturbative calculation of the chiral EFT is needed to obtain a robust result to be compared with the recent experimental measurement of flavor asymmetry in the proton.
↳ hep-phnucl-thPRC(2024)·4 citations
08
Quantum computation in fermionic thermal field theories
Wenyang Qian🇪🇸 · Bin Wu🇪🇸
Thermal properties of quantum fields at finite temperature are crucial to understanding strongly interacting matter and recent development in quantum computing has provided an alternative and promising avenue of study. In this work, we study thermal field theories involving only fermions using quantum algorithms. We first delve into the presentations of fermion fields via qubits on digital quantum computers alongside the quantum algorithms such as quantum imaginary time evolutions employed to evaluate thermal properties of generic quantum field theories. Specifically, we show numerical results such as the thermal distribution and the energy density of thermal field theories for Majorana fermions in 1+1 dimensions using quantum simulators. In addition to free field theory, we also study the effects of interactions resulting from coupling with a spatially homogeneous Majorana field. In both cases, we show analytically that thermal properties of the system can be described using phase-space distributions, and the quantum simulation results agree with analytical and semiclassical expectations. Our work is an important step to understand thermal fixed points, preparing for quantum simulation of thermalization in real time.
↳ hep-phhep-lathep-thnucl-th+1JHEP(2024)·11 citations

Affiliations

first authorsco-authorsvia INSPIRE