Nuclear Theory·nucl-th

Friday·February 1, 2019

12 papers—7 primary·5 cross-listed

01
[Submitted on 30 Jan 2019]
Symmetries and order in cluster nuclei
Roelof Bijker🇲🇽
It is shown that the rotational band structure of the cluster states in 12C and 16O can be understood in terms of the underlying discrete symmetry that characterizes the geometrical configuration of the alpha-particles, i.e. an equilateral triangle for 12C, and a regular tetrahedron for 16O. The structure of rotational bands provides a fingerprint of the underlying geometrical configuration of alpha-particles. Finally, some first results are presented for odd-cluster nuclei.
Comments:
Invited talk at Symmetries and Order: Algebraic Methods in Many-Body Systems, October 5-6, 2018, Yale University. 8 pages, 3 figures, 3 tables, to be published in AIP Conf. Proc. (2019)
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1901.11057 [pdf]
AIP Conf.Proc.(2019)·4 citations
02
[Submitted on 30 Jan 2019]
Ground-state properties of doubly magic nuclei from the unitary-model-operator approach with the chiral two- and three-nucleon forces
T. Miyagi · T. Abe · M. Kohno · P. Navratil · R. Okamoto · T. Otsuka · N. Shimizu · S. R. Stroberg
The ground-state energies and radii for $^{4}$ He, $^{16}$ O, and $^{40}$ Ca are calculated with the unitary-model-operator approach (UMOA). In the present study, we employ the similarity renormalization group (SRG) evolved nucleon-nucleon ( $N N$ ) and three-nucleon ( $3 N$ ) interactions based on the chiral effective field theory. This is the first UMOA calculation with both $N N$ and $3 N$ interactions. The calculated ground-state energies and radii are consistent with the recent {\it ab initio} results with the same interaction. We evaluate the expectation values with two- and three-body SRG evolved radius operators, in addition to those with the bare radius operator. With the aid of the higher-body evolution of radius operator, it is seen that the calculated radii tend to be SRG resolution-scale independent. We find that the SRG evolution gives minor modifications for the radius operator.
Comments:
11 pages, 7 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1901.11106 [pdf]
PRC(2019)·12 citations
03
[Submitted on 31 Jan 2019]
Dynamically Integrated Transport Approach for High-Energy Nuclear Collisions at High Baryon Density
Koichi Murase🇯🇵 · Yukinao Akamatsu🇯🇵 · Masayuki Asakawa🇯🇵 · Tetsufumi Hirano🇯🇵 · Masakiyo Kitazawa🇯🇵 · Kenji Morita🇵🇱 · Yasushi Nara🇯🇵 · Chiho Nonaka🇯🇵 · Akira Ohnishi🇯🇵
To explore the structure of the QCD phase diagram in high baryon density domain, several high-energy nuclear collision experiments in a wide range of beam energies are currently performed or planned using many accelerator facilities. In these experiments search for a first-order phase transition and the QCD critical point is one of the most important topics. To find the signature of the phase transition, experimental data should be compared to appropriate dynamical models which quantitatively describe the process of the collisions. In this study we develop a new dynamical model on the basis of the non-equilibrium hadronic transport model JAM and 3+1D hydrodynamics. We show that the new model reproduce well the experimental beam-energy dependence of hadron yields and particle ratio by the partial thermalization of the system in our core-corona approach.
Comments:
4 pages, 3 figures; contribution to the proceedings of the 8th International Conference on Quarks and Nuclear Physics (QNP2018), Tsukuba, November 13-17, 2018
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1901.11190 [pdf]
JPS Conf.Proc.(2019)·2 citations
04
[Submitted on 31 Jan 2019]
Probing QCD critical fluctuations from intermittency analysis in relativistic heavy-ion collisions
Jin Wu🇨🇳 · Yufu Lin🇨🇳 · Yuanfang Wu🇨🇳 · Zhiming Li🇨🇳
It is shown that intermittency, a self-similar correlation with respect to the size of the phase space volume, is sensitive to critical density fluctuations of baryon numbers in a system belonging to the three-dimensional (3D) Ising universality class. The relation between intermittency index and relative baryon density fluctuation is obtained. We thus suggest that measuring the intermittency in relativistic heavy-ion collisions could be used as a good probe of density fluctuations associated with the QCD critical phenomena. From recent preliminary results on neutron density fluctuations in central Au + Au collisions at $s_{N N}$ = 7.7, 11.5, 19.6, 27, 39, 62.4 and 200 GeV at RHIC/STAR, the collision energy dependence of intermittency index is extracted and shows a non-monotonic behavior with a peak at around 20 - 27 GeV, indicating that the strength of intermittency becomes the largest in this energy region. The transport UrQMD model without implementing critical physics cannot describe the observed behavior.
Comments:
Replaced with the published version
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1901.11193 [pdf]
PLB(2020)·31 citations
05
[Submitted on 31 Jan 2019]
Variational calculation of nuclear matter in finite particle number approach using unitary correlation operator and high-momentum pair methods
Takayuki Myo · Hiroki Takemoto · Mengjiao Lyu · Niu Wan · Chang Xu · Hiroshi Toki · Hisashi Horiuchi · Taiichi Yamada · Kiyomi Ikeda
We propose a new variational method for describing nuclear matter from nucleon-nucleon interaction. We use the unitary correlation operator method (UCOM) for central correlation to treat the short-range repulsion and further include the two-particle two-hole (2p2h) excitations of nucleon pair involving a large relative momentum, which is called 'high-momentum pair'(HM). We describe nuclear matter in finite size with finite particle number on periodic boundary condition and increase the 2p2h configurations until we get the convergence of the total energy per particle. We demonstrate the validity of this 'UCOM+HM' framework by applying it to the symmetric nuclear and neutron matters with the Argonne V4 $^{'}$ potential having short-range repulsion. The nuclear equations of state obtained in UCOM+HM are fairly consistent to those of other calculations such as Brueckner-Hartree-Fock and auxiliary field diffusion Monte Carlo in the overall density region.
Comments:
12 pages, 24 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1901.11338 [pdf]
PRC(2019)·9 citations
06
[Submitted on 31 Jan 2019]
Equation of state of dense matter in the multimessenger era
Ying Zhou🇨🇳 · Lie-Wen Chen🇨🇳 · Zhen Zhang🇨🇳
While the equation of state (EOS) of symmetric nuclear matter (SNM) at suprasaturation densities has been relatively well constrained from heavy-ion collisions, the EOS of high-density neutron-rich matter is still largely uncertain due to the poorly known high-density behavior of the symmetry energy. Using the constraints on the EOS of SNM at suprasaturation densities from heavy-ion collisions together with the data of finite nuclei and the existence of $2 M_{⊙}$ neutron stars from electromagnetic (EM) observations, we show that the high-density symmetry energy cannot be too soft, which leads to lower bounds on dimensionless tidal deformability of $Λ_{1.4} \geq 193$ and radius of $R_{1.4} \geq 11.1$ km for $1.4 M_{⊙}$ neutron star. Furthermore, we find that the recent constraint of $Λ_{1.4} \leq 580$ from the gravitational wave signal GW170817 detected from the binary neutron star merger by the LIGO and Virgo Collaborations rules out too stiff high-density symmetry energy, leading to an upper limit of $R_{1.4} \leq 13.3$ km. All these terrestrial nuclear experiments and astrophysical observations based on strong, EM and gravitational measurements together put stringent constraints on the high-density symmetry energy and the EOS of SNM, pure neutron matter and neutron star matter.
Comments:
6 pages, 4 figures. Discussions added. Accepted version to appear in PRD as a Rapid Communication
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1901.11364 [pdf]
PRD(2019)·64 citations
07
[Submitted on 31 Jan 2019]
Parton Distribution Functions from a Light Front Hamiltonian and QCD Evolution for Light Mesons
Jiangshan Lan🇨🇳 · Chandan Mondal🇨🇳 · Shaoyang Jia🇺🇸 · Xingbo Zhao🇨🇳 · James P. Vary🇺🇸
We obtain the pion and the kaon parton distribution functions from the eigenstates of a light front effective Hamiltonian in the constituent quark-antiquark representation suitable for low-momentum scale applications. By taking these scales as the only free parameters, the valence quark distribution functions of the pion, after QCD evolution, are consistent with the data from the FNAL-E615 experiment. The ratio of the up quark distribution of the kaon to that of the pion also agrees with the CERN-NA3 experiment. Supplemented by known parton distribution functions for the nucleons, we further obtain the cross section consistent with experimental data for the $π^{-} nucleus \to μ^{+} μ^{-} X$ Drell-Yan process.
Comments:
6 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1901.11430 [pdf]
PRL(2019)·132 citations
08
[Submitted on 20 Dec 2018] (cross-list from physics.chem-ph)
A formally exact one-frequency-only Bethe-Salpeter-like equation. Similarities and differences between GW +BSE and self-consistent RPA
Valerio Olevano🇫🇷 · Julien Toulouse (LCT)🇫🇷 · Peter Schuck (IPNO, LPMMC)🇫🇷
A formally exact Bethe-Salpeter-like equation for the linear-response function is introduced with a kernel which depends only on the one frequency of the applied field. This is in contrast with the standard Bethe-Salpeter equation (BSE) which involves multiple-frequency integrals over the kernel and response functions. From the one-frequency kernel, known approximations are straightforwardly recovered. However, the present formalism lends itself to more powerful approximations. This is demonstrated with the exact analytical solution of the Hubbard molecule. Similarities and differences of the $G W$ +BSE approach with the self-consistent random-phase approximation (RPA) is also discussed.
Subjects:
physics.chem-ph (physics.chem-ph); cond-mat.other (cond-mat.other); Nuclear Theory (nucl-th)
arXiv:
1812.08421 [pdf]
J.Chem.Phys.(2019)·15 citations
09
[Submitted on 30 Jan 2019] (cross-list from hep-ph)
Modeling neutrino-nucleus interactions for neutrino oscillation experiments
G. D. Megias🇪🇸 · S. Dolan🇫🇷 · S. Bolognesi🇫🇷
We present our recent progress on the relativistic modeling of neutrino-nucleus reactions for their implementation in MonteCarlo event generators (GENIE, NEUT) employed in neutrino oscillation experiments. We compare charged-current neutrino and antineutrino cross sections obtained within the SuSAv2 model, which is based on the Relativistic Mean Field theory and on the analysis of the superscaling behavior exhibited by ( $e, e^{'}$ ) data. We also evaluate and discuss the impact of multi-nucleon excitations arising from 2p-2h states excited by the action of weak forces in a fully relativistic framework, showing for the first time their implementation in GENIE and their comparison with recent T2K data.
Comments:
2 pages, 1 figure. Rabida 18 - International Scientific Meeting on Nuclear Physics: Basic concepts in Nuclear Physics: theory, experiments and applications. La Rábida (Spain) 18th-22th June 2018. To be published in Springer Proceedings in Physics
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1901.11022 [pdf]
Springer Proc.Phys.(2019)·4 citations
10
[Submitted on 31 Jan 2019] (cross-list from hep-ph)
Revealing minijet dynamics via centrality dependence of the double parton interactions in proton-nucleus interactions
Massimiliano Alvioli🇮🇹 · Maxim Azarkin🇷🇺 · Boris Blok🇮🇱 · Mark Strikman🇺🇸
One of the main challenges hampering an accurate measurement of the double parton scattering (DPS) cross sections is the difficulty in separating the DPS from the leading twist (LT) contributions. We argue that such a separation can be achieved, and cross section of DPS measured, by exploiting the different centrality dependence of DPS and LT processes in proton-nucleus scattering. We developed a Monte Carlo implementation of the DPS processes which includes realistic nucleon-nucleon (NN) correlations in nuclei, an accurate description of transverse geometry of both hard and soft NN collisions as well as fluctuations of the strength of interaction of nucleon with nucleus (color fluctuation effects). Our method allows the calculation of probability distributions of single and double dijet events as a function of centrality, also distinguishing double hard scatterings originating from a single target nucleon and from two different nucleons. We present numerical results for the rate of DPS as a function of centrality, which relates the number of wounded nucleons and the sum of transverse energy of hadrons produced at large negative (along the nucleus direction) rapidities, which is experimentally measurable. We suggest a new quantity which allows to test the geometry of DPS and we argue that it is a universal function of centrality for different DPS processes. This quantity can be tested by analyzing existing LHC data. The method developed in this work can be extended to the search for triple parton interactions.
Comments:
19 pages, 7 figures. Added analysis of color fluctuation effects, updated figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1901.11266 [pdf]
EPJC(2019)·15 citations
11
[Submitted on 31 Jan 2019] (cross-list from nucl-ex)
Possibilities of future double beta decay experiments to investigate inverted and normal ordering region of neutrino mass
A.S. Barabash🇷🇺
An overview of modern experiments on the search for neutrinoless double decay is presented. The obtained limits on the effective mass of the Majorana neutrino $⟨ m_{ν} ⟩$ are discussed taking into account the uncertainties in the value of the nuclear matrix elements (NMEs) and the value of the axial-vector constant $g_{A}$ . Predictions for the values of $⟨ m_{ν} ⟩$ from the results of oscillation experiments and modern cosmological data are presented. The possibilities of the next generation experiments with sensitivity to $⟨ m_{ν} ⟩$ at the level of $\sim$ 10-50 meV (studying mainly the inverted ordering (IO) region) are discussed. %Description of the most developed and promising projects is presented. The prospects for studying the normal ordering (NO) region are discussed too. It is shown that the possibilities of studying the NO depend on the mass of the lightest neutrino m $_{0}$ . In the limiting case of small mass (m $_{0}$ $\leq$ 0.1 meV), the values of $⟨ m_{ν} ⟩$ $\approx$ 1-4 meV are predicted, which makes the study of this region inaccessible by the next generation experiments. But there is an allowed region of m $_{0}$ (7-30 meV) in the framework of NO, where the predicted values for $⟨ m_{ν} ⟩$ could be $\sim$ 10-30 meV and that is quite achievable for the next generation experiments. The possibility to rich in the future sensitivity to $⟨ m_{ν} ⟩$ at the level of $\sim$ 1-10 meV is also discussed.
Comments:
11 pages, 1 figures, 3 tables
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1901.11342 [pdf]
Front.in Phys.(2019)·26 citations
12
[Submitted on 31 Jan 2019] (cross-list from hep-th)
JIMWLK evolution and small-x asymptotics of 2n-tuple Wilson line correlators
Khatiza Banu🇮🇳 · Mariyah Siddiqah🇮🇳 · Raktim Abir🇮🇳
JIMWLK equation tells how gauge invariant higher order Wilson line correlators would evolve at high energy. In this article we present a convenient integro-differential form of this equation, for 2n-tuple correlator, where all real and virtual terms are explicit. The `real' terms correspond to splitting (say at position z) of this 2n-tuple correlator to various pairs of 2m-tuple and (2n+2-2m)-tuple correlators whereas `virtual' terms correspond to splitting into pairs of 2m-tuple and (2n-2m)-tuple correlators. Kernels of virtual terms with m=0 (no splitting) and of real terms with m=1 (splitting with atleast one dipole) have poles and when integrated over z they do generate ultraviolet logarithmic divergences, separately for real and virtual terms. Except these two cases in all other terms the corresponding kernels, separately for real and virtual terms, have rather soften ultraviolet singularity and when integrated over z do not generate ultraviolet logarithmic divergences. We went on to study the solution of the JIMWLK equation for the 2n-tuple Wilson line correlator in the strong scattering regime where all transverse distances are much larger than inverse saturation momentum and shown that it also exhibits geometric scaling like color dipole deep inside saturation region.
Comments:
12 pages, 2 figures
Subjects:
High Energy Physics — Theory (hep-th); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1901.11531 [pdf]
PRD(2019)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE