Nuclear Theory·nucl-th

Tuesday·May 16, 2017

8 papers—4 primary·4 cross-listed

01
Interference Effect Between Neutron Direct and Resonance Capture Reactions For Neutron-Rich Nuclei
Futoshi Minato · Tokuro Fukui
Interference effect of neutron capture cross section between the compound and direct processes is investigated. The compound process is calculated by resonance parameters and the direct process by the potential mode. The interference effect is tested for neutron-rich $^{82}$ Ge and $^{134}$ Sn nuclei relevant to $r$ -process and light nucleus $^{13}$ C which is neutron poison in the $s$ -process and produces long-lived radioactive nucleus $^{14}$ C ( $T_{1/2} = 5700$ y). The interference effects in those nuclei are significant around resonances, and low energy region if $s$ -wave neutron direct capture is possible. Maxwellian averaged cross sections at $k T = 30$ and $300$ keV are also calculated, and the interference effect changes the Maxwellian averaged capture cross section largely depending on resonance position.
nucl-thnucl-exEPJ Web Conf.(2017)·1 citation
02
Solitonic excitations in collisions of superfluid nuclei: a qualitatively new phenomenon distinct from the Josephson effect
Kazuyuki Sekizawa · Gabriel Wlazłowski · Piotr Magierski
Recently, we have reported a novel role of pairing in low-energy heavy ion reactions at energies above the Coulomb barrier, which may have a detectable impact on reaction outcomes, such as the kinetic energy of fragments and the fusion cross section [arXiv:1611.10261, arXiv:1702.00069]. The phenomenon mimics the one studied experimentally with ultracold atomic gases, where two clouds of fermionic superfluids with different phases of the pairing fields are forced to merge, inducing various excitation modes of the pairing field. Although it originates from the phase difference of the pairing fields, the physics behind it is markedly different from the so-called Josephson effect. In this short contribution, we will briefly outline the results discussed in our recent papers and explain relations with the field of ultracold atomic gases.
nucl-thcond-mat.quant-gascond-mat.supr-connucl-exEPJ Web Conf.(2017)·11 citations
03
Configuration mixing in low-lying spectra of carbon hypernuclei
H. Xia🇨🇳 · H. Mei🇺🇸 · J. M. Yao🇺🇸
We perform a coupled-channels study of the low-lying states in $_{Λ}^{13, 15, 17, 19}$ C with a covariant energy density functional based microscopic particle-core coupling model. The energy differences of $1/ 2^{-}$ and $3/ 2^{-}$ states in $_{Λ}^{13}$ C and $_{Λ}^{15}$ C are predicted to be 0.25 MeV and 0.34 MeV, respectively. We find that configuration mixings in the $1/ 2^{-}$ and $3/ 2^{-}$ states of $_{Λ}^{15}$ C are the weakest among those of $_{Λ}^{13, 15, 17, 19}$ C. It indicates that $_{Λ}^{15}$ C provides the best candidate among the carbon hypernuclei to study the spin-orbit splitting of $p_{Λ}$ hyperon state.
nucl-thnucl-exSCPMA(2017)·10 citations
04
Empirical information on nuclear matter fourth-order symmetry energy from an extended nuclear mass formula
Rui Wang · Lie-Wen Chen
We establish a relation between the equation of state (EOS) of nuclear matter and the fourth-order symmetry energy $a_{sym, 4} (A)$ of finite nuclei in a semi-empirical nuclear mass formula by self-consistently considering the bulk, surface and Coulomb contributions to the nuclear mass. Such a relation allows us to extract information on nuclear matter fourth-order symmetry energy $E_{sym, 4} (ρ_{0})$ at normal nuclear density $ρ_{0}$ from analyzing nuclear mass data. Based on the recent precise extraction of $a_{sym, 4} (A)$ via the double difference of the "experimental" symmetry energy extracted from nuclear masses, for the first time, we estimate a value of $E_{sym, 4} (ρ_{0}) = 20.0 \pm 4.6$ MeV. Such a value of $E_{sym, 4} (ρ_{0})$ is significantly larger than the predictions from mean-field models and thus suggests the importance of considering the effects of beyond the mean-field approximation in nuclear matter calculations.
nucl-thastro-ph.SRnucl-exPLB(2017)·20 citations

Affiliations

first authorsco-authorsvia INSPIRE

Interference Effect Between Neutron Direct and Resonance Capture Reactions For Neutron-Rich Nuclei

Solitonic excitations in collisions of superfluid nuclei: a qualitatively new phenomenon distinct from the Josephson effect

Configuration mixing in low-lying spectra of carbon hypernuclei

Empirical information on nuclear matter fourth-order symmetry energy from an extended nuclear mass formula

Affiliations