Nuclear Theory·nucl-th

Tuesday·November 1, 2022

9 papers—6 primary·3 cross-listed

01
Production cross-sections of new superheavy elements with Z = 119-120 in fusion-evaporation reactions
Zi-Han Wang · Peng-Hui Chen · Xiang-Hua Zeng · Zhao-Qing Feng
We have calculated production cross sections of new superheavy elements with atomic number Z=119,120 in the fusion-evaporation reactions of $^{48}$ Ca+ $^{252}$ Es, $^{48}$ Ca+ $^{257}$ Fm, $^{49}$ Sc+ $^{252}$ Es, $^{49}$ Sc+ $^{251}$ Cf, $^{50}$ Ti+ $^{247}$ Bk, $^{50}$ Ti+ $^{251}$ Cf, $^{51}$ V+ $^{247}$ Cm, $^{51}$ V+ $^{247}$ Cf, $^{54}$ Cr+ $^{243}$ Am, $^{54}$ Cr+ $^{247}$ Cm, $^{56}$ Mn+ $^{244}$ Pu, $^{56}$ Mn+ $^{243}$ Am, $^{60}$ Fe+ $^{237}$ Np, $^{60}$ Fe+ $^{244}$ Pu, $^{61}$ Co+ $^{238}$ U, $^{61}$ Co+ $^{237}$ Np, $^{64}$ Ni+ $^{231}$ Pa, $^{64}$ Ni+ $^{238}$ U, $^{65}$ Cu+ $^{232}$ Th, $^{65}$ Cu+ $^{231}$ Pa, and $^{68}$ Zn+ $^{232}$ Th within the dinuclear system model systematically. The inner fusion barriers have been extracted from the driving potential or potential energy surface which could be used to predict the relative fusion probability roughly. The influence of mass asymmetry of the colliding partners on the production of new superheavy elements (SHE) has been investigated systematically. It is found that fusion probability increase along with the increasing mass asymmetry of colliding systems. The Ti-induced reactions have the largest cross-sections of the new SHE. The dependence of production cross-sections of new superheavy elements on the isospin of projectile nuclei has been discussed. The new SHE of $^{289 - 295}$ 119 has been predicted as the synthesis cross sections around serval picobarns in the $^{46, 48, 50, 52}$ Ti-induced reactions. Production cross-section of the element of $^{295}$ 120 has been evaluated as large as 1 picobarn in the reactions $^{46}$ Ti ( $^{251}$ Cf, 2n) $^{295}$ 120 at $E^{*}$ = 26 MeV. The optimal projectile-target combinations and beam energies for producing new SHE with atomic number Z=119-120 are proposed for the forthcoming experiments.
nucl-thNucl.Phys.Rev.(2022)·2 citations
02
Muonic-Atom Spectroscopy and Impact on Nuclear Structure and Precision QED Theory
Aldo Antognini🇨🇭 · Sonia Bacca🇩🇪 · Andreas Fleischmann🇩🇪 · Loredana Gastaldo🇩🇪 · Franziska Hagelstein🇨🇭 · Paul Indelicato🇫🇷 · Andreas Knecht🇨🇭 · Vadim Lensky🇩🇪 · Ben Ohayon🇨🇭 · Vladimir Pascalutsa🇩🇪 · Nancy Paul🇫🇷 · Randolf Pohl🇩🇪 · Frederik Wauters🇩🇪
Recent progress in laser and x-ray spectroscopy of muonic atoms offers promising long-term possibilities at the intersection of atomic, nuclear and particle physics. In muonic hydrogen, laser spectroscopy measurements will determine the ground-state hyperfine splitting (HFS) and additionally improve the Lamb shift by a factor of 5. Precision spectroscopy with cryogenic microcalorimeters has the potential to significantly improve the charge radii of the light nuclei in the $Z = 3 - 8$ range. Complementary progress in precision should be achieved on the theory of nucleon- and nuclear-structure effects. The impact of this muonic-atom spectroscopy program will be amplified by the upcoming results from H and He $^{+}$ spectroscopy, simple molecules such as HD $^{+}$ and Penning trap measurements. In this broader context, one can test ab-initio nuclear theories, bound-state QED for two- or three-body systems, and determine fundamental constants, such as the Rydberg ( $R_{\infty}$ ) and the fine-structure ( $α$ ) constants.
nucl-thhep-phphysics.atom-ph16 citations
03
Probing fluctuations and correlations of strangeness by net-kaon cumulants in Au+Au collisions at $s_{N N} = 7.7$ GeV
Qian Chen🇨🇳 · Han-Sheng Wang🇨🇳 · Guo-Liang Ma🇨🇳
We calculate the cumulants and correlation functions of net-kaon multiplicity distributions in Au+Au collisions at $s_{N N} = 7.7$ GeV using a multiphase transport model (AMPT) with both a new coalescence mechanism and all charge conservation laws. The AMPT model can qualitatively describe the centrality dependences of the net-kaon cumulants and cumulant ratios measured by the STAR experiment. By focusing on the stage evolution of the cumulants, cumulant ratios, and correlation functions, we reveal several key effects on the fluctuations and correlations of strangeness during the dynamical evolution of relativistic heavy-ion collisions, including strangeness production and diffusion, hadronization, hadronic rescatterings, and weak decays. Without considering the quantum chromodynamics critical fluctuations in the dynamic model, we demonstrate that the net-kaon fluctuations can largely represent the net-strangeness fluctuations. Our results provide a baseline for understanding the net-kaon and net-strangeness fluctuations, which help to search for the possible critical behaviors at the critical end point in relativistic heavy-ion collisions.
nucl-thhep-phnucl-exPRC(2023)·6 citations
04
Directed flow of $Λ$ from heavy-ion collisions and hyperon puzzle of neutron stars
Akira Ohnishi🇯🇵 · Asanosuke Jinno🇯🇵 · Koichi Murase🇯🇵 · Yasushi Nara🇯🇵
We examine the $Λ$ potential from the chiral effective field theory ( $χ$ EFT) via the $Λ$ directed flow from heavy-ion collisions. We implement the $Λ$ potential obtained from the $χ$ EFT in a vector potential version of relativistic quantum molecular dynamics. We find that the $Λ$ potentials obtained from the $χ$ EFT assuming weak momentum dependence reproduce the $Λ$ directed flow measured by the STAR collaboration in the Beam Energy Scan program. While the $Λ$ directed flow is not very sensitive to the density dependence of the potential, the directed flow at large rapidities is susceptible to the momentum dependence. Thus understanding the directed flow of hyperons in a wide range of beam energy and rapidity is helpful in understanding hyperon potentials in dense matter.
nucl-thhep-phEPJ Web Conf.(2022)·3 citations
05
The Fusion-by-Diffusion model as a tool to calculate cross sections for the production of superheavy nuclei
T. Cap · M. Kowal · K. Siwek-Wilczyńska
This article summarizes recent progress in our understanding of the reaction mechanisms leading to the formation of superheavy nuclei in cold and hot fusion reactions. Calculations are done within the Fusion-by-Diffusion (FBD) model using the new nuclear data tables by Jachimowicz et al. [At. Data Nucl. Data Tables 138, 101393 (2021)]. The synthesis reaction is treated in a standard way as a three-step process (i.e., capture, fusion, and survival). Each reaction step is analyzed separately. Model calculations are compared with selected experimental data on capture, fissionlike and fusion cross sections, fusion probabilities, and evaporation residue excitation functions. The role of the angular momentum in the fusion step is discussed in detail. A set of fusion excitation functions with corresponding fusion probabilities is provided for cold and hot synthesis reactions.
nucl-thEPJA(2022)·10 citations
06
Wavefunction matching for solving quantum many-body problems
Serdar Elhatisari · Lukas Bovermann · Yuanzhuo Ma · Evgeny Epelbaum · Dillon Frame · Fabian Hildenbrand · Myungkuk Kim · Youngman Kim · Hermann Krebs · Timo A. Lähde · Dean Lee · Ning Li and 6 other authors
Ab initio calculations play an essential role in our fundamental understanding of quantum many-body systems across many subfields, from strongly correlated fermions to quantum chemistry and from atomic and molecular systems to nuclear physics. One of the primary challenges is to perform accurate calculations for systems where the interactions may be complicated and difficult for the chosen computational method to handle. Here we address the problem by introducing a new approach called wavefunction matching. Wavefunction matching transforms the interaction between particles so that the wavefunctions up to some finite range match that of an easily computable interaction. This allows for calculations of systems that would otherwise be impossible due to problems such as Monte Carlo sign cancellations. We apply the method to lattice Monte Carlo simulations of light nuclei, medium-mass nuclei, neutron matter, and nuclear matter. We use high-fidelity chiral effective field theory interactions and find good agreement with empirical data. These results are accompanied by new insights on the nuclear interactions that may help to resolve long-standing challenges in accurately reproducing nuclear binding energies, charge radii, and nuclear matter saturation in ab initio calculations.
nucl-thcond-mat.quant-gashep-latnucl-ex+1Nature(2024)·110 citations
07
Path-integral approaches to strongly-coupled quantum many-body systems
Kilian Fraboulet🇫🇷
The core of this thesis is the path-integral formulation of quantum field theory and its ability to describe strongly-coupled quantum many-body systems of finite size. Collective behaviors can be efficiently described in such systems through the implementation of spontaneous symmetry breaking (SSB) in mean-field approaches. However, as the thermodynamic limit does not make sense in finite-size systems, the latter can not exhibit any SSB and the symmetries which are broken down at the mean-field level must therefore be restored. The efficiency of theoretical approaches in the treatment of finite-size quantum systems can therefore be studied via their ability to restore spontaneously broken symmetries. In this thesis, a zero-dimensional $O (N)$ model is taken as a theoretical laboratory to perform such an investigation with many state-of-the-art path-integral techniques: perturbation theory combined with various resummation methods (Padé-Borel, Borel-hypergeometric, conformal mapping), enhanced versions of perturbation theory (transseries derived via Lefschetz thimbles, optimized perturbation theory), self-consistent perturbation theory based on effective actions (auxiliary field loop expansion (LOAF), Cornwall-Jackiw-Tomboulis (CJT) formalism, 4PPI effective action, ...), functional renormalization group (FRG) techniques (FRG based on the Wetterich equation, DFT-FRG, 2PI-FRG). Connections between these different techniques are also emphasized. In addition, the path-integral formalism provides us with the possibility to introduce collective degrees of freedom in an exact fashion via Hubbard-Stratonovich transformations: the effect of such transformations on the aforementioned methods is also examined in detail.
↳ cond-mat.str-elnucl-thquant-ph3 citations
08
Higher twists effects in DIS on nuclei at the EIC and LHeC: A phenomenological analysis
Yan B. Bandeira🇧🇷 · Victor P. Goncalves🇧🇷
In this paper we investigate the impact of the higher - twist effects, resummed by the non - linear approaches for the QCD dynamics, on the inclusive observables that will be measured in future electron - ion colliders. We assume a phenomenological model for the dipole - nucleus scattering amplitude which takes into account the non - linear corrections and estimate the contribution of the different twists for $F_{2}^{A} (x, Q^{2})$ , $F_{L}^{A} (x, Q^{2})$ and $\partial F_{2}^{A} / \partial l n Q^{2}$ considering different values of the Bjorken - $x$ variable, photon virtuality $Q^{2}$ and atomic number $A$ . A comparison with the full predictions is performed and the impact of the distinct twists is estimated. Our results indicate that a future analysis of the logarithmic $Q^{2}$ slope and longitudinal structure function will allow us to probe the presence of the non - linear effects on the QCD dynamics.
↳ hep-phnucl-thEPJA(2023)·3 citations
09
Inclusive production of $J / ψ$ , $ψ (2 S)$ , and $Υ$ states in pNRQCD
Nora Brambilla🇩🇪 · Hee Sok Chung🇩🇪 · Antonio Vairo🇩🇪 · Xiang-Peng Wang🇩🇪
Under some assumptions on the hierarchy of relevant energy scales, we compute the nonrelativistic QCD (NRQCD) long-distance matrix elements (LDMEs) for inclusive production of $J / ψ$ , $ψ (2 S)$ , and $Υ$ states based on the potential NRQCD (pNRQCD) effective field theory. Based on the pNRQCD formalism, we obtain expressions for the LDMEs in terms of the quarkonium wavefunctions at the origin and universal gluonic correlators, which do not depend on the heavy quark flavor or the radial excitation. This greatly reduces the number of nonperturbative unknowns and substantially enhances the predictive power of the nonrelativistic effective field theory formalism. We obtain improved determinations of the LDMEs for $J / ψ$ , $ψ (2 S)$ , and $Υ$ states thanks to the universality of the gluonic correlators, and obtain phenomenological results for cross sections and polarizations at large transverse momentum that agree well with measurements at the LHC.
↳ hep-phhep-exhep-latnucl-thJHEP(2023)·39 citations

Affiliations

first authorsco-authorsvia INSPIRE