Nuclear Theory·nucl-th

Friday·March 12, 2021

10 papers—5 primary·5 cross-listed

01
Ab initio calculations of electric dipole moments of light nuclei
Paul Froese🇨🇦 · Petr Navratil🇨🇦
In any finite system, the presence of a non-zero permanent electric dipole moment (EDM) would indicate CP violation beyond the small violation predicted in the Standard Model. Here, we use the ab initio no-core shell model (NCSM) framework to theoretically investigate the magnitude of the nuclear EDM. We calculate EDMs of several light nuclei using chiral two- and three-body interactions and a PT-violating Hamiltonian based on a one-meson-exchange model. We present a benchmark calculation for $^{3}$ He, as well as results for the more complex nuclei $^{6, 7}$ Li, $^{9}$ Be, $^{10, 11}$ B, $^{13}$ C, $^{14, 15}$ N, and $^{19}$ F. Our results suggest that different nuclei can be used to probe different terms of the PT violating interaction. These calculations allow us to suggest which nuclei may be good candidates in the search for a measurable permanent electric dipole moment.
nucl-thhep-thPRC(2021)·28 citations
02
Weinberg's proposal of 1990: A very personal view
R. Machleidt🇺🇸
My personal encounter with Weinberg's proposal of 1990 was a really entertaining one: My collaborator David Entem and I had embarked to show that Weinberg's idea, though smart and beautiful, was essentially useless in practice (like so many of those genius ideas of the 1980s where people claimed to have "derived the nuclear force from QCD"). However, in trying to do so, we showed the opposite; namely, we showed that Weinberg's idea worked better than allowed by any reasonable means.
nucl-thhep-phnucl-exphysics.hist-phFew Body Syst.(2021)·7 citations
03
Search for a viable nucleus-nucleus potential for heavy-ion nuclear reactions
T.Nandi · D.K. Swami · P.S. Damodara Gupta · Yash Kumar · S. Chakraborty · H.C. Manjunatha
We have constructed an empirical formulae for the fusion and interaction barriers using experimental values available till date. The fusion barriers so obtained have been compared with different model predictions based on the proximity, Woods-Saxon and double folding potentials along with several empirical formulas, time dependent Hartree-Fock theories, and the experimental results. The comparison allows us to find the best model, which is nothing but the present empirical formula only. Most remarkably, the fusion barrier and radius show excellent consonance with the experimental findings for the reactions meant for synthesis of the superheavy elements also. Furthermore, it is seen that substitution of the predicted fusion barrier and radius in classic Wong formula [C. Wong, Phys. Rev. Lett. {31}, 766 (1973)] for the total fusion cross sections satisfies very well with the experiments. Similarly, current interaction barrier predictions have also been compared well with a few experimental results available and Bass potential model meant for the interaction barrier predictions. Importantly, the present formulae for the fusion as well as interaction barrier will have practical implications in carrying out the physics research near the Coulomb barrier energies. Furthermore, present fusion barrier and radius provide us a good nucleus-nucleus potential useful for numerous theoretical applications.
nucl-thPramana(2022)·6 citations
04
Shock Waves in Relativistic Anisotropic Hydrodynamics
Aleksandr Kovalenko · Andrey Leonidov
Shock wave solutions in anisotropic relativistic hydrodynamics are considered. A new phenomenon of anisotropy-related angular deflection of the incident flow by the shock wave front is described. Patterns of velocity and momentum transformation by the shock wave front are described.
nucl-thEPJC(2022)·6 citations
05
Ab initio computation of the longitudinal response function in $^{40}$ Ca
J. E. Sobczyk🇩🇪 · B. Acharya🇩🇪 · S. Bacca🇩🇪 · G. Hagen🇺🇸
We present a consistent \emph{ab initio} computation of the longitudinal response function $R_{L}$ in $^{40}$ Ca using the coupled-cluster and Lorentz integral transform methods starting from chiral nucleon-nucleon and three-nucleon interactions. We validate our approach by comparing our results for $R_{L}$ in $^{4}$ He and the Coulomb sum rule in $^{40}$ Ca against experimental data and other calculations. For $R_{L}$ in $^{40}$ Ca we obtain a very good agreement with experiment in the quasi-elastic peak up to intermediate momentum transfers, and we find that final state interactions are essential for an accurate description of the data. This work presents a milestone towards \emph{ab initio} computations of neutrino-nucleus cross sections relevant for experimental long-baseline neutrino programs.
nucl-thhep-exhep-phnucl-exPRL(2021)·57 citations
06
A cornucopia of antineutrons and hyperons from super J/psi factory for next-generation nuclear and particle physics high-precision experiments
Chang-Zheng Yuan🇨🇳 · Marek Karliner🇮🇱
In order to study the interactions and structure of various types of matter one typically needs to carry out scattering experiments utilizing many different particles as projectiles. Whereas beams of $e^{\pm}$ , $μ^{\pm}$ , $π^{\pm}$ , $K^{\pm}$ , proton, antiproton, and of various heavy ions have been produced and have enabled many scientific breakthroughs, beams of antineutrons, hyperons ( $Λ$ , $Σ$ and $Ξ$ ) and their antiparticles are typically not easy to obtain. Here we point out and investigate a new high-quality source of these particles: a super $J / ψ$ factory with capability of accumulating trillions of $J / ψ$ decays each year. In the relevant $J / ψ$ decays the desired particle is produced together with other final state particles that can be tagged. This allows accurate determination of the flux and momentum of the projectile, enabling unprecedented precision-study of the corresponding interactions with a broad range of targets. These novel high-statistics sources of baryons and antibaryons with precisely known kinematics open fresh opportunities for applications in particle and nuclear physics, including antinucleon-nucleon interaction, nonvalence $s s ˉ$ component of the nucleon, (anti)hyperon-nucleon interaction, OZI violation, (multi-strange) hypernuclei, exotic light hadron spectroscopy and many others, as well as calibration of Monte Carlo simulation for hadronic and medical physics.
↳ hep-exhep-phnucl-exnucl-thPRL(2021)·41 citations
07
Positronium: an illustration of nonperturbative renormalization in a basis light-front approach
Xingbo Zhao🇨🇳 · Kaiyu Fu🇨🇳 · Hengfei Zhao🇨🇳 · James P. Vary🇺🇸
We calculate the mass spectrum and the structure of the positronium system at a strong coupling in a basis light-front approach. We start from the light-front QED Hamiltonian and retain one dynamical photon in our basis. We perform the fermion mass renormalization associated with the nonperturbative fermion self-energy correction. We present the resulting mass spectrum and wave functions for the selected low-lying states. Next, we apply this approach to QCD and calculate the heavy meson system with one dynamical gluon retained. We illustrate the obtained mass spectrum and wave functions for the selected low-lying states.
↳ hep-phnucl-thPoS(2020)·14 citations
08
$P_{c} (4312)^{+}$ , $P_{c} (4380)^{+}$ , and $P_{c} (4457)^{+}$ as double triangle cusps
Satoshi X. Nakamura (Univ. of Science and Technology of China)🇨🇳
Understanding the nature of the hidden charm pentaquark(like) signals in the LHCb data for $Λ_{b}^{0} \to J / ψ p K^{-}$ is a central problem of hadron spectroscopy. We propose a scenario completely different from previous ones such as hadron molecules and compact pentaquarks. We identify relevant double triangle mechanisms with leading or lower-order singularities. The associated anomalous threshold cusps at the $Σ_{c}^{(*)} D ˉ^{(*)}$ thresholds are significantly more singular than the ordinary ones. Then we demonstrate that the double triangle amplitudes reproduce the peak structures of $P_{c} (4312)^{+}$ , $P_{c} (4380)^{+}$ , and $P_{c} (4457)^{+}$ in the LHCb data, through an interference with other common mechanisms. Only the $P_{c} (4440)^{+}$ peak is due to a resonance with width and strength significantly smaller than previously estimated. $P_{c}^{+}$ signals are expected in other processes and the proposed model (partly) explains the current data such as: the GlueX $J / ψ$ photoproduction data with no $P_{c}^{+}$ signals; the LHCb $Λ_{b}^{0} \to J / ψ p π^{-}$ data with a possible signal only from $P_{c} (4440)^{+}$ . The double triangle singularity is now a possible option to interpret resonancelike structures near thresholds in general.
↳ hep-phhep-exnucl-thPRD(2021)·66 citations
09
From Short-Range to Contact Interactions in Two-dimensional Many-Body Quantum Systems
Marcel Griesemer🇩🇪 · Michael Hofacker🇩🇪
Quantum systems composed of $N$ distinct particles in $R^{2}$ with two-body contact interactions of TMS type are shown to arise as limits - in the norm resolvent sense - of Schrödinger operators with suitably rescaled pair potentials.
↳ math-phmath.MPnucl-thquant-phAnnales Henri Poincare(2022)·7 citations
10
Enstrophy without boost symmetry
Natalia Pinzani-Fokeeva🇮🇹 · Amos Yarom🇮🇱
We construct an approximately conserved current for $2 + 1$ dimensional, Aristotelian (non boost invariant), fluid flow. When Aristotelian symmetry is enhanced to Galilean symmetry, this current matches the enstrophy current responsible for the inverse cascade in incompressible fluids. Other enhancements of Aristotelian symmetry discussed in this work include Lorentzian, Carrollian and Lifshitz scale symmetry.
↳ hep-thcond-mat.softnucl-thphysics.flu-dynSciPost Phys.(2022)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE