Nuclear Theory·nucl-th

Monday·May 1, 2017

12 papers—7 primary·5 cross-listed

01
Inclusive Breakup Theory of Three-Body Halos
M. S. Hussein · L. A. Souza · E. Chimanski · B. V. Carlson · T. Frederico
We present a recently developed theory for the inclusive breakup of three-fragment projectiles within a four-body spectator model \cite{CarPLB2017}, for the treatment of the elastic and inclusive non-elastic break up reactions involving weakly bound three-cluster nuclei in $A (a, b) X$ / $a = x_{1} + x_{2} + b$ collisions. The four-body theory is an extension of the three-body approaches developed in the 80's by Ichimura, Autern and Vincent (IAV) \cite{IAV1985}, Udagawa and Tamura (UT) \cite{UT1981} and Hussein and McVoy (HM) \cite{HM1985}. We expect that experimentalists shall be encouraged to search for more information about the $x_{1} + x_{2}$ system in the elastic breakup cross section and that also further developments and extensions of the surrogate method will be pursued, based on the inclusive non-elastic breakup part of the $b$ spectrum.
nucl-thnucl-exEPJ Web Conf.(2017)·3 citations
02
Probing three-nucleon-force effects via (p,2p) reactions
Kosho Minomo · Michio Kohno · Kazuki Yoshida · Kazuyuki Ogata
We propose to use proton knockout reactions (p,2p) from a deeply bound orbit as a new probe into three-nucleon-force (3NF) effects. The remarkable advantage of using (p,2p) reaction is that we can choose an appropriate kinematical condition to probe the 3NF effects. We analyze (p,2p) reactions on a 40Ca target within the framework of distorted-wave impulse approximation with a g-matrix interaction based on chiral two- and three-nucleon forces. The chiral 3NF effects significantly change the peak height of the triple differential cross section of (p,2p) reaction. We also clarify the correspondence between the (p,2p) cross sections and the in- medium pp cross sections.
nucl-thPRC(2017)·7 citations
03
Superfluid Density of Neutrons in the Inner Crust of Neutron Stars: New Life for Pulsar Glitch Models
Gentaro Watanabe · C. J. Pethick
Calculations of the effects of band structure on the neutron superfluid density in the crust of neutron stars made under the assumption that the effects of pairing are small [N. Chamel, Phys. Rev. C 85, 035801 (2012)] lead to moments of inertia of superfluid neutrons so small that the crust alone is insufficient to account for the magnitude of neutron star glitches. Inspired by earlier work on ultracold atomic gases in an optical lattice, we investigate fermions with attractive interactions in a periodic lattice in the mean-field approximation. The effects of band structure are suppressed when the pairing gap is of order or greater than the strength of the lattice potential. By applying the results to the inner crust of neutron stars, we conclude that the reduction of the neutron superfluid density is considerably less than previously estimated and, consequently, it is premature to rule out models of glitches based on neutron superfluidity in the crust.
nucl-thastro-ph.HEcond-mat.quant-gasPRL(2017)·84 citations
04
Quark mean field model with pion and gluon corrections for $Λ, Ξ^{0}$ hypernuclei and neutron stars
Xueyong Xing🇨🇳 · Jinniu Hu🇨🇳 · Hong Shen🇨🇳
Properties of $Λ, Ξ^{0}$ hypernuclei and neutron stars are investigated in quark mean field model with pion and gluon corrections. Firstly, $u, d$ , and $s$ quarks are confined by relativistic harmonic oscillator potentials to generate the baryons, like nucleon, $Λ, Σ$ , and $Ξ$ hyperons. The effects of pion-quark coupling and one-gluon exchange are considered perturbatively. Then, the baryons interact with each other through exchanging $σ, ω,$ and $ρ$ mesons between quarks in hypernuclei and nuclear matter. The strengths of confinement potentials for $u, d,$ and $s$ quarks are determined by the masses and radii of free baryons. The coupling constants between the quarks and mesons are fixed by the ground-state properties of several nuclei and single-hyperon potentials at nuclear saturation density, which arises three parameter sets for the coupling constants between mesons and quarks, named QMF-NK1S, QMF-NK2S, and QMF-NK3S. Compared to the results of previous quark mean field model without pion and gluon corrections, it is found that properties of $Λ$ hypernuclei, i.e. the single $Λ$ energies, are more consistent with the experimental observables. Properties of $Ξ^{0}$ hypernuclei are also calculated and compared with the results in previous quark mean field model. With these three parameter sets, the neutron stars containing hyperons are investigated through solving the Tolman-Oppenheimer-Volkoff equation. Maximum masses of neutron stars approach $2.1 M_{⊙}$ with hyperons and corresponding radii are around $13$ km.
nucl-thPRC(2017)·19 citations
05
The limits of the nuclear landscape explored by the relativistic continuum Hatree-Bogoliubov theory
X. W. Xia · Y. Lim · P. W. Zhao · H. Z. Liang · X. Y. Qu · Y. Chen · H. Liu · L. F. Zhang · S. Q. Zhang · Y. Kim · J. Meng
The ground-state properties of nuclei with 8 $\leq$ Z $\leq$ 120 from the proton drip line to the neutron drip line have been investigated using the relativistic continuum Hartree-Bogoliubov (RCHB) theory with the relativistic density functional PC-PK1. With the effects of the continuum included, there are totally 9035 nuclei predicted to be bound, which largely extends the existing nuclear landscapes predicted with other methods. The calculated binding energies, separation energies, neutron and proton Fermi surfaces, root-mean-square (rms) radii of neutron, proton, matter, and charge distributions, ground-state spins and parities are tabulated. The extension of the nuclear landscape obtained with RCHB is discussed in detail, in particular for the neutron-rich side, in comparison with the relativistic mean field calculations without pairing correlations and also other predicted landscapes. It is found that the coupling between the bound states and the continuum due to the pairing correlations plays an essential role in extending the nuclear landscape. The systematics of the separation energies, radii, densities, potentials and pairing energies of the RCHB calculations are also discussed. In addition, the alpha-decay energies and proton emitters based on the RCHB calculations are investigated.
nucl-thAtom.Data Nucl.Data Tabl.(2018)·175 citations
06
Two bosons in a narrowly resonant trap
Bingwei Long🇨🇳 · Jianfeng Wang🇨🇳 · Songlin Lyu🇨🇳
It is rare for an $S$ -wave resonance to remain narrow while approaching threshold as a result of the interaction parameters being fine tuned. Such an interaction is, however, realized by pion-charmed baryon system $π Σ_{c}$ , which has a narrow resonance $Λ_{c}^{+} (2595)$ located a few MeVs above its threshold. We study the consequence of narrowly resonant inter-species interaction in a three-body system composed of two identical light bosons and an extremely heavy particle. We concern ourselves in the present paper with resonances of the three-body system, as opposed to bound states. The focus is on the technical aspects of constructing the integral equation for three-body amplitudes and of analytically continuing the integral equation to locate the "trimer" resonance pole in the unphysical sheet of the center-of-mass energy plane.
nucl-thcond-mat.quant-gashep-ph3 citations
07
Elastic and inelastic pion-nucleon scattering to fourth order in chiral perturbation theory
D. Siemens🇩🇪 · V. Bernard🇫🇷 · E. Epelbaum🇩🇪 · A. M. Gasparyan🇷🇺 · H. Krebs🇩🇪 · Ulf-G. Meißner🇩🇪
We extend our previous study of elastic pion-nucleon scattering in the framework of chiral perturbation theory by performing a combined analysis of the reactions $π N \to π N$ and $π N \to π π N$ . The calculation is carried out to fourth order in the chiral expansion using the heavy baryon approach and the covariant formulation supplemented with a modified version of the extended on-mass-shell renormalization scheme. We demonstrate that a combined fit to experimental data in both channels leads to a reduced amount of correlations between the low-energy constants. A satisfactory description of the experimental data in both channels is obtained, which is further improved upon including tree-level contributions of the $Δ$ (1232) resonance. We also explore a possibility of using the empirical information about $π N$ subthreshold parameters obtained recently by means of the Roy-Steiner equations to stabilize the fits.
nucl-thhep-phPRC(2017)·35 citations
08
Fluid Dynamics far from Local Equilibrium
Paul Romatschke🇺🇸
Fluid dynamics is traditionally thought to apply only to systems near local equilibrium. In this case, the effective theory of fluid dynamics can be constructed as a gradient series. Recent applications of resurgence suggest that this gradient series diverges, but can be Borel-resummed, giving rise to a hydrodynamic attractor solution which is well defined even for large gradients. Arbitrary initial data quickly approaches this attractor via non-hydrodynamic mode decay. This suggests the existence of a new theory of far-from-equilibrium fluid dynamics. In this work, the framework of fluid dynamics far from local equilibrium for conformal system is introduced, and the hydrodynamic attractor solutions for rBRSSS, kinetic theory in the relaxation time approximation, and strongly-coupled N=4 SYM are identified for a system undergoing Bjorken flow.
↳ hep-thnucl-thphysics.flu-dynPRL(2018)·264 citations
09
Interpretation of $Y (4390)$ as an isoscalar partner of $Z (4430)$ from $D^{*} (2010) D ˉ_{1} (2420)$ interaction
Jun He🇨🇳 · Dian-Yong Chen🇨🇳
Invoked by the recent observation of $Y (4390)$ at BESIII, which is about 40 MeV below the $D^{*} (2010) D ˉ_{1} (2420)$ threshold, we investigate possible bound and resonance states from the $D^{*} (2010) D ˉ_{1} (2420)$ interaction with the one-boson-exchange model in a quasipotential Bethe-Salpeter equation approach. A bound state with quantum number $0^{-} (1^{--})$ is produced at 4384 MeV from the $D^{(} 2010) D ˉ_{1} (2420)$ interaction, which can be related to experimentally observed $Y (4390)$ . Another state with quantum number $1^{+} (1^{+})$ is also produced at $4461 + i 39$ MeV from this interaction. Different from the $0^{-} (1^{--})$ state, the $1^{+} (1^{+})$ state is a resonance state above the $D^{*} (2010) D ˉ_{1} (2420)$ threshold. This resonance state can be related to the first observed charged charmonium-like state $Z (4430)$ , which has a mass about 4475 MeV measured above the threshold as observed at Belle and LHCb. Our result suggests that $Y (4390)$ is an isoscalar partner of the $Z (4430)$ as a hadronic-molecular state from the $D^{*} (2010) D ˉ_{1} (2420)$ interaction.
↳ hep-phhep-exhep-latnucl-thEPJC(2017)·19 citations
10
Production and absorption of exotic bottomonium-like states in high energy heavy ion collisions
L. M. Abreu🇧🇷 · K. P. Khemchandani🇧🇷 · A. Martínez Torres🇧🇷 · F. S. Navarra🇧🇷 · M. Nielsen🇧🇷 · A. L. Vasconcellos🇧🇷
We investigate the production and absorption of $Z_{b} (10610)$ and $Z_{b}^{'} (10650)$ states in a hadronic medium, via the processes $B ˉ^{(*)} B^{(*)} \to π Z_{b}^{(')}$ and the corresponding inverses reactions. We use effective field Lagrangians based on an $S U (4)$ -extension of the hidden gauge formalism to account for the couplings between light and heavy mesons, and a phenomenological Lagrangian involving the $B^{*} B^{(*)} Z_{b}^{(')}$ vertices. The absorption cross sections are found to be much larger than the production ones.
↳ hep-phnucl-thPRD(2017)·11 citations
11
Effect of nuclear quadrupole moment on parity nonconservation in atoms
V. V. Flambaum · V. A. Dzuba · C. Harabati
Nuclei with spin $I \geq 1$ have a weak quadrupole moment which leads to tensor contribution to the parity non-conserving interaction between nuclei and electrons. We calculate this contribution for Yb $^{+}$ , Fr and Ra $^{+}$ and found it to be small. In contrast, in many lanthanides (e.g., Nd, Gd, Dy, Ho, Er, Pr, Sm) and Ra close levels of opposite parity lead to strong enhancement of the effect making it sufficiently large to be measured. Another possibility is to measure the PNC transitions between the hyperfine components of the ground state of Bi. Since nuclear weak charge is dominated by neutrons this opens a way of measuring quadrupole moments of neutron distribution in nuclei.
↳ physics.atom-phnucl-thPRA(2017)·15 citations
12
Status and challenges of neutrino cross sections
Marco Martini🇫🇷
Neutrino oscillations physics entered in the precision era. In this context accelerator-based neutrino experiments need a reduction of systematic errors to the level of a few percent. Today one of the most important sources of systematic errors are the neutrino-nucleus cross sections. The status of our knowledge of these cross sections in the different open channels in the few-GeV region, i.e. the quasielastic, the pion production and the multinucleon emission, is reviewed. Special emphasis is devoted to the multinucleon emission channel, which attracted a lot of attention in the last few years. It is crucial to properly reconstruct the neutrino energy which enters the expression of the oscillation probability. This channel was not included in the generators used for the analyses of the neutrino cross sections and oscillations experiments.
↳ hep-phhep-exnucl-th0 citations

Affiliations

first authorsco-authorsvia INSPIRE