Nuclear Theory·nucl-th

Tuesday·April 6, 2021

16 papers—9 primary·7 cross-listed

01
Exploring the structure of $^{29}$ Ne
Manju🇮🇳 · M. Dan🇮🇳 · G. Singh🇪🇸 · Jagjit Singh🇯🇵 · Shubhchintak🇧🇪 · R. Chatterjee🇮🇳
We apply a fully quantum mechanical Coulomb breakup theory under the aegis of post form finite-range distorted wave Born approximation to analyze the elastic Coulomb breakup of $^{29}$ Ne on $^{208}$ Pb at $244$ \,MeV/u. We calculate several reaction observables to quantify its structural parameters. One-neutron removal cross-section is calculated to check the consistency of the ground state configuration of $^{29}$ Ne with the available experimental data. A scrutiny of the parallel momentum distribution of the charged fragment reveals a full width at half maximum of $82$ \,MeV/c, which is in good agreement with the experimental value and indicates a moderate halo for a nearly spherical $^{29}$ Ne in the $^{28}$ Ne $(0^{+}) \otimes 2 p_{3/2} ν$ ground state. The energy-angular distributions and average momentum of the charged fragment point to the absence of post-acceleration effects in the breakup process, a desirable result for the elastic breakup.
nucl-thNPA(2021)·7 citations
02
Hybrid stars can be self-bound
Li-Qun Su🇨🇳 · Yan Yan🇨🇳 · Cheng-Ming Li🇨🇳 · Yong-Feng Huang🇨🇳 · Hongshi Zong🇨🇳
Based on the properties of uniform nuclear matter at the nuclear saturation density and basic thermodynamic relations, we first re-study the composition of matter on the surface of normal neutron stars and hybrid stars. It is found that the hybrid stars are composed of uniform hadronic matter on the surface rather than heavy nuclei. Then we use the Walceka model and the self-consistent NJL model to describe the equation of state of low-density hadrons and quark matter at high densities respectively, and the P--interpolation method is employed to connect the equation of state at the extreme densities to study hybrid stars. As a result, we find that the obtained hybrid star mass-radius relation and tidal deformability meet the latest astronomical data. More importantly, we find that the hybrid stars we obtained can be self-bound rather than gravitationally bound, which is completely different from previous related studies.
nucl-thhep-phPRD(2021)·6 citations
03
Scaling with deformation in probable $p$ -wave halo $^{34}$ Na
Manju · Jagjit Singh · Shubhchintak · R. Chatterjee
We investigate the electric dipole response of $^{34}$ Na, a probable $p$ -wave one-neutron halo nucleus, lying in the "island of inversion" and having a deformed structure. We use a semi-analytic approach to probe the dipole response and further compare the results obtained from a post form finite-range distorted wave Born approximation theory of Coulomb breakup. The effects of deformation are figured out on the peak positions of the electric dipole strength distribution which further constraint the one-neutron separation energy of the deformed projectile and it leads to a two-dimensional scaling of total $B (E 1)$ strength with parameters: separation energy and deformation.
nucl-thJ.Phys.Conf.Ser.(2020)·0 citations
04
Equilibrium constants of nuclear reactions in supernova explosions
Jorge A. Muñoz · Marcos A. García · Jorge A. López
We study the change in internal rotational energy in the transformation of protons to neutrons in the \b{eta}-decay reactions that take place in the collapse of the iron core of massive stars that precede type II supernova explosions. We consider an ensemble of electrons, protons, neutrons and neutrinos undergoing \b{eta}-decay reactions, treat the protons and neutrons as triatomic rotors, evaluate the equilibrium constant to obtain the change in rotational energy during the proton-to-neutron transformation. We estimate such change for a variety of conditions, and compare to the energy released in a supernova explosion.
nucl-thastro-ph.SRIJMPE(2022)·0 citations
05
Neutrino energy reconstruction from semi-inclusive samples
R. González-Jiménez🇪🇸 · M. B. Barbaro🇮🇹 · J. A. Caballero🇪🇸 · T. W. Donnelly🇺🇸 · N. Jachowicz🇧🇪 · G. D. Megias🇪🇸 · K. Niewczas🇧🇪 · A. Nikolakopoulos🇧🇪 · J. W. Van Orden🇺🇸 · J. M. Udías🇪🇸
We study neutrino-nucleus charged-current reactions on finite nuclei for the situation in which an outgoing muon and a proton are detected in coincidence, i.e., we focus on semi-inclusive cross sections. We limit our attention to one-body current interactions (quasielastic scattering) and assess the impact of different nuclear effects in the determination of the neutrino energy. We identify the regions in phase space where the neutrino energy can be reconstructed relatively well, and study whether the cross section in those regions is significant. Our results indicate that it is possible to filter more than 50% of all events according to the muon and proton kinematics, so that for the DUNE and T2K fluxes the neutrino energy can be determined with an uncertainty of less than 1% and 3%, respectively. Furthermore, we find that the reconstructed neutrino energy does not depend strongly on how one treats the final-state interactions and is not much affected by the description of the initial state. On the other hand, the estimations of the uncertainty on the neutrino energy show important sensitivity to the modeling of the initial state.
nucl-thhep-exhep-phnucl-exPRC(2022)·35 citations
06
Effective field theory for shallow P-wave states
E. Epelbaum🇩🇪 · J. Gegelia🇩🇪 · H.P. Huesmann🇩🇪 · U.-G. Meißner🇩🇪 · X.-L. Ren🇩🇪
We discuss the formulation of a non-relativistic effective field theory for two-body P-wave scattering in the presence of shallow states and critically address various approaches to renormalization proposed in the literature. It is demonstrated that the consistent renormalization involving only a finite number of parameters in the well-established formalism with auxiliary dimer fields corresponds to the inclusion of an infinite number of counterterms in the formulation with contact interactions only. We also discuss the implications from the Wilsonian renormalization group analysis of P-wave scattering.
nucl-thhep-phhep-thFew Body Syst.(2021)·15 citations
07
Manipulating strong electromagnetic fields with the average transverse momentum of relativistic nuclear collisions
Giuliano Giacalone🇩🇪 · Chun Shen🇺🇸
We show that an event-shape engineering based on the mean transverse momentum of charged hadrons, $[p_{t}]$ , provides an optimal handle on the strength of the magnetic field created in central heavy-ion collisions at high energy. This is established through quantitative evaluations of the correlation existing between the event-by-event magnetic field produced by the spectator protons in 5.02 TeV Pb+Pb collisions and the event-by-event $[p_{t}]$ at a given collision centrality. We argue that the event selection based on $[p_{t}]$ provides a better handle on the magnetic field than the more traditional selection based on the event ellipticities. Advantages brought by this new method for the experimental search of the chiral magnetic effect are discussed.
nucl-thhep-exhep-phnucl-exEPJA(2021)·4 citations
08
The "Folk Theorem" on Effective Field Theory: A Case for Nuclear Physics
Mannque Rho🇫🇷
Although largely unrecognized, Gerry Brown had played a seminal and prescient role for the development of the currently heralded "first-principles approach" to nuclear dynamics known as "nuclear effective field theory" ( $n$ EFT for short). I give a brief account in what way he entered -- together with his Korean colleagues -- at the earliest stage of its development and what he left behind for the future in paving the road to go {\it way beyond} the standard $n$ EFT. I do this in the context of Gerry's original conceptual ideas conceived after the "dilepton fiasco" that indicate a surprising new role of hidden local and scale symmetries in nuclear physics.
nucl-thnucl-ex1 citation
09
Two-body wave functions and compositeness from scattering amplitudes: II. Application to the physical $N^{*}$ and $Δ^{*}$ resonances
Takayasu Sekihara🇯🇵
The meson-baryon molecular components for the $N^{*}$ and $Δ^{*}$ resonances are investigated in terms of the compositeness, which is defined as the norm of the two-body wave function from the meson-baryon scattering amplitudes. The scattering amplitudes are constructed in a $π N$ - $η N$ - $σ N$ - $ρN$ - $π Δ$ coupled-channels problem in a meson exchange model together with several bare $N^{*}$ and $Δ^{*}$ states, and parameters are fitted so as to reproduce the on-shell $π N$ partial wave amplitudes up to the center-of-mass energy 1.9 GeV with the orbital angular momentum $L \leq 2$ . As a result, the Roper resonance $N (1440)$ is found to be dominated by the $π N$ and $σ N$ molecular components while the bare-state contribution is small. The squared wave functions in coordinate space imply that both in the $π N$ and $σ N$ channels the separation between the meson and baryon is about more than 1 fm for the $N (1440)$ resonance. On the other hand, dominant meson-baryon molecular components are not observed in any other $N^{*}$ and $Δ^{*}$ resonances in the present model, although they have some fractions of the meson-baryon clouds.
nucl-thhep-exhep-phnucl-exPRC(2021)·10 citations

Affiliations

first authorsco-authorsvia INSPIRE