Nuclear Theory·nucl-th

Tuesday·February 5, 2019

19 papers—9 primary·10 cross-listed

01
[Submitted on 2 Feb 2019]
Impact of the nuclear mass uncertainties on the r process
Z. Y. Wang · Q. G. Wen · T. H. Heng
Based on a simple site-independent approach, we attempt to reproduce the solar $r$ -process abundance with four nuclear mass models, and investigate the impact of the nuclear mass uncertainties on the $r$ process. In this paper, we first analyze the reliability of an adopted empirical formula for $β$ -decay half-lives which is a key ingredient for the $r$ process. Then we apply four different mass tables to study the $r$ -process nucleosynthesis together with the calculated $β$ -decay half-lives, and the existing $β$ -decay data from FRDM+QRPA is also considered for comparison. The numerical results show that the main features of the solar $r$ -process pattern and the locations of the abundance peaks can be reproduced well via the $r$ -process simulations. Moreover, we also find that the mass uncertainties can significantly affect the derived astrophysical conditions for the $r$ -process site, and resulting in a remarkable impact on the $r$ process.
Comments:
12 pages, 4 figures.Accepted by International Journal of Modern Physics E, in press
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1902.00642 [pdf]
IJMPE(2019)·0 citations
02
[Submitted on 2 Feb 2019]
Effects of strong magnetic fields on neutron $^{3} P_{2}$ superfluidity with spin-orbit interactions
Shigehiro Yasui🇯🇵 · Chandrasekhar Chatterjee🇯🇵 · Muneto Nitta🇯🇵
We discuss neutron $^{3} P_{2}$ phases in the core of neutron stars in strong magnetic field (magnetars). The neutron $^{3} P_{2}$ pairing provides a wide variety of condensates, such as the uniaxial nematic and (D $_{2}$ and D $_{4}$ ) biaxial nematic, with different symmetries stemming from the combinations of spin and momentum. Based on the spin-orbital angular momentum coupling and the spin-magnetic field coupling of the neutrons, we derive the Ginzburg-Landau equation containing higher order terms of the magnetic field. We investigate the phase diagram of the neutron $^{3} P_{2}$ superfluidity, and find that the D $_{2}$ biaxial nematic phase is extended by the higher order terms of the magnetic field. We also discuss the thermodynamic properties, the heat capacity and the spin susceptibility.
Comments:
Prepared for proceedings of QNP-2018, "The 8th International Conference on Quarks and Nuclear Physics" to be published in JPS Conf. Proc. Based on the original paper arXiv:1810.04901 [nucl-th]
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Superconductivity (cond-mat.supr-con); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1902.00674 [pdf]
JPS Conf.Proc.(2019)·11 citations
03
[Submitted on 2 Feb 2019]
Nuclear electric dipole moment as a good probe of CP violation
Nodoka Yamanaka🇫🇷
The electric dipole moment (EDM) is an excellent probe of new physics beyond the standard model of particle physics. The EDM of light nuclei is particularly interesting due to the high sensitivity to the hadron level CP violation. In this proceedings contribution, we investigate the mechanism of the generation of the EDM for several light nuclei and the prospect for the discovery of new physics.
Comments:
4 pages, 1 figure, proceedings of the 8th International Conference on Quarks and Nuclear Physics (QNP2018), November 13-17, 2018
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1902.00755 [pdf]
JPS Conf.Proc.(2019)·0 citations
04
[Submitted on 3 Feb 2019]
Jost function based on the Hartree-Fock-Bogoliubov formalism
K. Mizuyama · N. Nhu Le · T. Dieu Thuy · T. V. Nhan Hao
We formulate the Jost function formalism based on the Hartree-Fock-Bogoliubov (HFB) theory which has been used to represent the nature of the superfluidity of nucleus. The Jost function based on the HFB can give the analytic representation of the S-matrix for the nucleon elastic scattering targeting on the open-shell nucleus taking into account the pairing effect. By adopting the Woods-Saxon potential, we show the numerical results of S-matrix poles and their trajectories with varying the pairing strength in two cases of Fermi energies. The total cross sections in each cases for neutron elastic scattering are also analyzed, and we confirmed some staggering shapes or sharp resonances originated from the effect of pairing can be seen in the cross section.
Comments:
Submitted to Physical Review C
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1902.00852 [pdf]
PRC(2019)·12 citations
05
[Submitted on 3 Feb 2019]
Three- and four-body kaonic nuclear states: Binding energies and widths
Sajjad Marri🇮🇷 · Jafar Esmaili🇮🇷
Using separable potentials for $K ˉ N - π Σ$ interaction, we investigated four-body kaonic nuclear systems such as $K^{-} pp n$ and $K^{-} K^{-} pp$ , with the Faddeev AGS method in the momentum representation. The Faddeev calculations are based on the quasi-particle method and the method of the energy dependent pole expansion was used to obtain the separable representation for the integral kernels in the three- and four-body equations. Different types of $K ˉ N - π Σ$ potentials based on phenomenological and chiral SU(3) approach are used and it was shown that the kaonic nuclear systems under consideration are tightly bound.
Comments:
17 pages, 3 figures, Eur. Phys. J. A (2019) 55: 43
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1902.00903 [pdf]
EPJA(2019)·18 citations
06
[Submitted on 3 Feb 2019]
GW170817 constraints on the properties of a neutron star in the presence of WIMP dark matter
Abdul Quddus🇮🇳 · Grigorios Panotopoulos🇵🇹 · Bharat Kumar🇮🇳 · Shakeb Ahmad🇮🇳 · S. K. Patra🇮🇳
The properties of a neutron star are studied in the presence of dark matter. We have considered a relatively light Weakly Interacting Massive Particle (WIMP) as a dark matter candidate with properties suggested by the results of the DAMA/LIBRA collaboration, realized for instance within the framework of the Next-to-Minimal Supersymmetric Standard Model. The dark matter particle interacts with the baryonic matter of a neutron star through Higgs bosons. The dark matter variables are essentially fixed using the results of the DAMA/LIBRA experiment, which are then used to build the Lagrangian density for the WIMP-nucleon interaction inside a neutron star. We have used the effective field theory motivated relativistic mean field model to study the equations-of-state in the presence of dark matter. The predicted equations-of-state are used in the Tolman-Oppenheimer-Volkoff equations to obtain the mass-radius relations, the moment of inertia, and effects of the tidal field on a neutron star. The calculated properties are compared with the corresponding data of the GW170817 event.
Comments:
10 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1902.00929 [pdf]
J.Phys.G(2020)·62 citations
07
[Submitted on 3 Feb 2019]
Bayesian optimization in ab initio nuclear physics
A. Ekström🇸🇪 · C. Forssén🇸🇪 · C. Dimitrakakis🇸🇪 · D. Dubhashi🇸🇪 · H. T. Johansson🇸🇪 · A. S. Muhammad🇸🇪 · H. Salomonsson🇸🇪 · A. Schliep🇸🇪
Theoretical models of the strong nuclear interaction contain unknown coupling constants (parameters) that must be determined using a pool of calibration data. In cases where the models are complex, leading to time consuming calculations, it is particularly challenging to systematically search the corresponding parameter domain for the best fit to the data. In this paper, we explore the prospect of applying Bayesian optimization to constrain the coupling constants in chiral effective field theory descriptions of the nuclear interaction. We find that Bayesian optimization performs rather well with low-dimensional parameter domains and foresee that it can be particularly useful for optimization of a smaller set of coupling constants. A specific example could be the determination of leading three-nucleon forces using data from finite nuclei or three-nucleon scattering experiments.
Comments:
33 pages, 14 figures
Subjects:
Nuclear Theory (nucl-th); Machine Learning (cs.LG); Machine Learning (stat.ML)
arXiv:
1902.00941 [pdf]
J.Phys.G(2019)·23 citations
08
[Submitted on 4 Feb 2019]
Nuclear collective dynamics in the lattice Hamiltonian Vlasov method
Rui Wang🇨🇳 · Lie-Wen Chen🇨🇳 · Zhen Zhang🇨🇳
The lattice Hamiltonian method is developed for solving the Vlasov equation with nuclear mean-field based on the Skyrme pseudopotential up to next-to-next-to-next-to leading order. The ground states of nuclei are obtained through varying the total energy with respect to the density distribution of nucleons. Owing to the self-consistent treatment of initial nuclear ground state and the exact energy conservation in the lattice Hamiltonian method, the present framework of solving the Vlasov equation exhibits very stable nuclear ground state evolution. As a first application of the new lattice Hamiltonian Vlasov method, we explore the iso-scalar giant monopole and iso-vector giant dipole modes of finite nuclei. The obtained results are shown to be comparable to that from random-phase approximation and consistent with the experimental data, indicating the capability of the present method in dealing with the long-time near-equilibrium nuclear dynamics.
Comments:
15 pages, 7 figures, 3 tables. Typos fixed to match the published version in PRC
Subjects:
Nuclear Theory (nucl-th); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Experiment (nucl-ex)
arXiv:
1902.01256 [pdf]
PRC(2019)·24 citations
09
[Submitted on 4 Feb 2019]
Galilean invariance restoration on the lattice
Ning Li🇺🇸 · Serdar Elhatisari🇩🇪 · Evgeny Epelbaum🇩🇪 · Dean Lee🇺🇸 · Bing-Nan Lu🇺🇸 · Ulf-G. Meißner🇩🇪
We consider the breaking of Galilean invariance due to different lattice cutoff effects in moving frames and a nonlocal smearing parameter which is used in the construction of the nuclear lattice interaction. The dispersion relation and neutron-proton scattering phase shifts are used to investigate the Galilean invariance breaking effects and ways to restore it. For $S$ -wave channels, $^{1} S_{0}$ and $^{3} S_{1}$ , we present the neutron-proton scattering phase shifts in moving frames calculated using both Lüscher's formula and the spherical wall method, as well as the dispersion relation. For the $P$ and $D$ waves, we present the neutron-proton scattering phase shifts in moving frames calculated using the spherical wall method. We find that the Galilean invariance breaking effects stemming from the lattice artifacts partially cancel those caused by the nonlocal smearing parameter. Due to this cancellation, the Galilean invariance breaking effect is small, and the Galilean invariance can be restored by introducing Galilean invariance restoration operators.
Comments:
13 pages, 7 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Lattice (hep-lat)
arXiv:
1902.01295 [pdf]
PRC(2019)·19 citations
10
[Submitted on 1 Feb 2019] (cross-list from hep-ph)
Enhancements and suppressions of CP violating effect in the nucleons, nuclei, and atoms
Nodoka Yamanaka🇫🇷
The electric dipole moment (EDM) is a very sensitive probe of CP violation beyond the standard model, and it as been measured in many systems such as atoms, neutrons, etc. The EDM of composite systems may be sensitive to several elementary level CP violating processes, but the theoretical evaluations of the CP violation at different physical (atomic, nuclear, hadronic, elementary) hierarchies are required to unveil them. In this context, we are particularly interested in which CP violating processes are enhanced in a given system, or vice versa. In this proceedings contribution, we will give an overview of the enhancement and suppression of CP violation in processes contributing to the EDMs of composite systems.
Comments:
11 pages, 4 figures, short review on the electric dipole moment, proceedings of the 23rd International Spin Symposium (SPIN 2018), September 10-14, 2018
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
arXiv:
1902.00527 [pdf]
PoS(2019)·2 citations
11
[Submitted on 2 Feb 2019] (cross-list from hep-ph)
Extracting jet transport parameter $q^$ from a multiphase transport model
Feng-Chu Zhou🇨🇳 · Guo-Liang Ma🇨🇳 · Yu-Gang Ma🇨🇳
Within a multi-phase transport model with string melting scenario, jet transport parameter $q^$ is calculated in Au+Au collisions at $s_{N N}$ = 200 GeV and Pb+Pb collisions at $s_{N N}$ = 2.76 TeV. The $q^$ increases with the increasing of jet energy for both partonic phase and hadronic phase. The energy and path length dependences of $q^$ in full heavy-ion evolution are consistent with the expectations of jet quenching. The correlation between jet transport parameter $q^$ and dijet transverse momentum asymmetry $A_{J}$ is mainly investigated, which discloses that a larger $q^$ corresponds to a larger $A_{J}$ . It supports a consistent jet energy loss picture from the two viewpoints of single jet and dijet. It is proposed to measure dijet asymmetry distributions with different jet transport parameter ranges as a new potential method to study jet quenching physics in high energy heavy-ion collisions.
Comments:
7 pages, 7 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1902.00729 [pdf]
EPJA(2020)·7 citations
12
[Submitted on 3 Feb 2019] (cross-list from hep-ph)
Propagation of QCD Color through Strongly Interacting Systems
William K Brooks🇨🇱 · Jorge López🇨🇱
The propagation of QCD color through atomic nuclei is studied via a new analysis using a geometric model of semi-inclusive deep inelastic scattering. The experimental data were previously published by the HERMES Collaboration and consisted of the multiplicity ratio observable (2007) and the transverse momentum broadening observable (2010). We perform a simultaneous fit of these two observables to estimate (1) the color lifetime of the quark, (2) quark energy loss, (3) the $q^$ transport coefficient, and (4) the cross section for hadronic interaction with the medium. We present preliminary results for this fit.
Comments:
4 pages, 3 figures; proceedings for the Eighth International Conference on Quarks and Nuclear Physics (QNP2018), Tsukuba, Japan. https://www-conf.kek.jp/qnp2018/
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1902.00886 [pdf]
JPS Conf.Proc.(2019)·0 citations
13
[Submitted on 3 Feb 2019] (cross-list from hep-ph)
How a spinning quark moves in the NJL type mean field
Feng Li🇩🇪
The transport equation of the spinning quarks, moving in the Nambu-Jona-Lasinio (NJL) type mean field, is derived by solving the Schwinger-Dyson equations, up to the order of $ℏ$ , under the mean field approximation. It shows that the scalar and the vector mean field potentials have different impacts on the quantum correction to the transport equation. Both the forces give rise to an anomalous velocity and an anomalous force where the latter would vanish if the vector force is turned off. The particle dispersion relation is modified by the vector force as well. Besides, the spin precession in the particle rest frame is purely governed by the vector force.
Comments:
9 pages
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1902.00915 [pdf]
1 citation
14
[Submitted on 4 Feb 2019] (cross-list from cond-mat.stat-mech)
Reworking the Zubarev's approach to non-equilibrium quantum statistical mechanics
F. Becattini (Florence U.)🇮🇹 · M. Buzzegoli (Florence U.)🇮🇹 · E. Grossi (Heidelberg U.)🇩🇪
In this work the non-equilibrium density operator approach introduced by Zubarev more than 50 years ago to describe quantum systems at local thermodynamic equilibrium is revisited. This method - which was used to obtain the first ''Kubo" formula of shear viscosity, is especially suitable to describe quantum effects in fluids. This feature makes it a viable tool to describe the physics of the Quark Gluon Plasma in relativistic nuclear collisions.
Comments:
9 pages, 1 figure. Submitted to special issue of Particles: "Nonequilibrium Phenomena in Strongly Correlated System"
Subjects:
Statistical Mechanics (cond-mat.stat-mech); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
1902.01089 [pdf]
Particles(2019)·84 citations
15
[Submitted on 4 Feb 2019] (cross-list from nucl-ex)
Has the neutral double hypernucleus $_{ΛΛ}^{4}$ n been observed?
Sebastian Bleser🇩🇪 · Michael Bölting🇩🇪 · Theodoros Gaitanos🇬🇷 · Josef Pochodzalla🇩🇪 · Falk Schupp🇩🇪 · Marcell Steinen🇩🇪
The BNL-AGS E906 experiment was the first fully electronic experiment to produce and study double hypernuclei with large statistics. Two dominant structures were observed in the correlated $π^{-}$ -- $π^{-}$ momentum matrix at (p $_{π - H}$ ,p $_{π - L}$ ) = (133,114) MeV/c and at (114,104) MeV/c. In this work we argue that the interpretation of the structure at (133,114) MeV/c in terms of $_{Λ}^{3}$ H+ $_{Λ}^{4}$ H pairs is questionable. We show, that neither a scenario where the hypernuclei are produced after capture of a stopped $Ξ^{-}$ by a $^{9}$ Be nucleus nor interactions of energetic $Ξ^{-}$ with $^{9}$ Be nuclei in the target material can produce a sufficient amount of such twin pairs. We have therefore explored the conjecture of Avraham Gal that decays of the $_{ΛΛ}^{4}$ n may be responsible for the observed structure. Indeed, the inclusion of $_{ΛΛ}^{4}$ n with a two-body $π^{-}$ branching ratio of 50 % in a statistical multifragmentation model allows to describe the E906 data remarkably well. On the other hand, a bound $_{Λ}^{3}$ n nucleus would cause a striking structure in the momentum correlation matrix which is clearly inconsistent with the observation of E906.
Comments:
4 figures
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1902.01118 [pdf]
PLB(2019)·10 citations
16
[Submitted on 31 Jan 2019] (cross-list from physics.ins-det)
A next-generation LHC heavy-ion experiment
D. Adamová🇨🇿 · G. Aglieri Rinella🇨🇭 · M. Agnello🇮🇹 · Z. Ahammed🇮🇳 · D. Aleksandrov🇷🇺 · A. Alici🇮🇹 · A. Alkin🇺🇦 · T. Alt🇩🇪 · I. Altsybeev🇷🇺 · D. Andreou🇨🇭 · A. Andronic🇩🇪 · F. Antinori🇮🇹 and 387 other authors
The present document discusses plans for a compact, next-generation multi-purpose detector at the LHC as a follow-up to the present ALICE experiment. The aim is to build a nearly massless barrel detector consisting of truly cylindrical layers based on curved wafer-scale ultra-thin silicon sensors with MAPS technology, featuring an unprecedented low material budget of 0.05% X $_{0}$ per layer, with the innermost layers possibly positioned inside the beam pipe. In addition to superior tracking and vertexing capabilities over a wide momentum range down to a few tens of MeV/ $c$ , the detector will provide particle identification via time-of-flight determination with about 20~ps resolution. In addition, electron and photon identification will be performed in a separate shower detector. The proposed detector is conceived for studies of pp, pA and AA collisions at luminosities a factor of 20 to 50 times higher than possible with the upgraded ALICE detector, enabling a rich physics program ranging from measurements with electromagnetic probes at ultra-low transverse momenta to precision physics in the charm and beauty sector.
Comments:
Input to the 2020 Update of the European Particle Physics Strategy
Subjects:
Instrumentation and Detectors (physics.ins-det); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1902.01211 [pdf]
63 citations
17
[Submitted on 4 Feb 2019] (cross-list from astro-ph.HE)
The Golden Era of Neutron Stars: from Hadrons to Quarks
Gordon Baym🇺🇸
Neutron stars were first posited in the early thirties, and discovered as pulsars in late sixties; however, only recently are we beginning to understand the matter they contain. This talk describes the continuing development of a consistent picture of the liquid interiors of neutron stars, driven by four advances: observations of two heavy neutron stars with masses $≃$ 2.0 solar masses; inferences of masses and radii simultaneously for an increasing number of neutron stars in low mass X-ray binaries, and future determinations via the NICER observatory; the observation of the binary neutron star merger, GW170817, through gravitational waves as well as across the electromagnetic spectrum; and an emerging understanding in QCD of how nuclear matter can turn into deconfined quark matter in the interior. We describe the modern quark-hadron crossover equation of state, QHC18, and the corresponding neutron stars, which agree well with current observations.
Comments:
6 pages, 6 figures, Proceedings, 8th Intl. Conference on Quarks and Nuclear Physics 2018 (Tsukuba, Japan), Nov. 2018
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
1902.01274 [pdf]
JPS Conf.Proc.(2019)·10 citations
18
[Submitted on 4 Feb 2019] (cross-list from gr-qc)
Probing gravity at sub-femtometer scales through the pressure distribution inside the proton
P. P. Avelino🇵🇹
Recently, a measurement of the pressure distribution experienced by the quarks inside the proton has found a strong repulsive (positive) pressure at distances up to 0.6 femtometers from its center and a (negative) confining pressure at larger distances. In this paper we show that this measurement puts significant constraints on modified theories of gravity in which the strength of the gravitational interaction on microscopic scales is enhanced with respect to general relativity. We consider the particular case of Eddington-inspired Born-Infeld gravity, showing that strong limits on $κ$ , the only additional parameter of the theory with respect to general relativity, may be derived from the quark pressure measurement ( $∣ κ ∣ \lsim 1 0^{- 1} m^{5} k g^{- 1} s^{- 2}$ ). Furthermore, we show how these limits may be significantly improved with precise measurements of the first and second moments of the pressure distribution inside the proton.
Comments:
6 pages
Subjects:
General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
1902.01318 [pdf]
PLB(2019)·24 citations
19
[Submitted on 4 Feb 2019] (cross-list from hep-ph)
QED and Fundamental Symmetries in Positronium Decays
Steven D. Bass🇵🇱
We discuss positronium decays with emphasis on tests of fundamental symmetries and the constraints from measurements of other precision observables involving electrons and photons.
Comments:
15 pages, to appear in Acta Physica Polonica B, based on a lecture presented at the 3rd Symposium on Positron Emission Tomography, Cracow, September 10-13 2018
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1902.01355 [pdf]
Acta Phys.Polon.B(2019)·56 citations

Affiliations

first authorsco-authorsvia INSPIRE