Nuclear Theory
New submissions
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New submissions for Thu, 21 Sep 17
 [1] arXiv:1709.06644 [pdf, other]

Title: The anisotropic nonequilibrium hydrodynamic attractorComments: 25 pages, 7 figuresSubjects: Nuclear Theory (nuclth); High Energy Physics  Phenomenology (hepph)
We determine the dynamical attractors associated with anisotropic hydrodynamics (aHydro) and the DNMR equations for a 0+1d conformal system using kinetic theory in the relaxation time approximation. We compare our results to the nonequilibrium attractor obtained from exact solution of the 0+1d conformal Boltzmann equation, NavierStokes theory, and secondorder MuellerIsraelStewart theory. We demonstrate that the aHydro attractor equation resums an infinite number of terms in the inverse Reynolds number. The resulting resummed aHydro attractor possesses a positive longitudinal to transverse pressure ratio and is virtually indistinguishable from the exact attractor. This suggests that kinetic theory involves not only a resummation in gradients (Knudsen number) but also a novel resummation in inverse Reynolds number. We also demonstrate that the DNMR result provides a better approximation to the exact kinetic theory attractor than MuellerIsraelStewart theory. Finally, we introduce a new method for obtaining approximate aHydro equations which relies solely on an expansion in inverse Reynolds number, carry out this expansion to third order, and compare these thirdorder results to the exact kinetic theory solution.
 [2] arXiv:1709.06699 [pdf, ps, other]

Title: A practical scheme for constructing the minimum weight states of the su(n)Lipkin model in arbitrary fermion numberAuthors: Y. Tsue (1), C. Providencia (2), J. da Providencia (2), M. Yamamura (3) ((1) Kochi Univ., Japan, (2) Univ. de Coimbra, Portugal, (3) Kansai Univ., Japan)Comments: 11 pages, 6 figuresSubjects: Nuclear Theory (nuclth)
With the aim of performing an argument supplement to the previous paper by the present authors, in this paper, a practical scheme for constructing the minimum weight states of the su(n)Lipkin model in arbitrary fermion number is discussed. The idea comes from the following two points : (i) consideration on the property of onefermion transfer induced by the su(n)generators in the Lipkin model and (ii) use of the auxiliary su(2)algebra presented by the present authors. The form obtained under the points (i) and (ii) is simple.
 [3] arXiv:1709.06704 [pdf, ps, other]

Title: The role of the elemental nature of A=3 nuclei in neutron rich nucleiComments: 4 pages, 3 figuresSubjects: Nuclear Theory (nuclth)
The idea of treating the trinucleon systems as elementary entities in the elementary particle model (EPM) as an Effective Field Theory, has been a success in explaining the weak chargechanging processes in nuclei. The EPM results are found to be as good as those obtained from nuclear microscopic models using two and threebody forces. We extend this concept to investigate the validity of the elemental nature of A=3 nuclei through studies of nuclear structure of neutron rich nuclei. By treating neutron rich nuclei as primarily made up of tritons as its building blocks, we extract onetriton and twotriton separation energies of these nuclei. Calculations have been performed within relativistic mean field (RMF) models with latest interactions. Clear evidence of a new shell structure with well defined predictions of new magic nuclei arise. The most significant and an unambiguous prediction of our model, is the existence of a superheavy nucleus $_{\:\:92}^{276}{\rm U}_{184}$, which due to its small charge Z=92, should be easily accessible to experimental confirmation.
 [4] arXiv:1709.06840 [pdf, other]

Title: Electromagnetic Strength Distributions from the Ab Initio NoCore Shell ModelComments: 6 pages, 3 figuresSubjects: Nuclear Theory (nuclth); Nuclear Experiment (nuclex)
We present an ab initio approach for the description of collective excitations and transition strength distributions of arbitrary nuclei up into the sdshell that based on the NoCore Shell Model in combination with the Lanczos strengthfunction method. Starting from two and threenucleon interactions from chiral effective field theory, we investigate the electric monopole, dipole, and quadrupole response of the even oxygen isotopes from 16O to 24O. The method describes the full energy range from lowlying excitations to the giant resonance region and beyond in a unified and consistent framework, including a complete description of fragmentation and finestructure. This opens unique opportunities for understanding dynamic properties of nuclei from first principles and to further constrain nuclear interactions. We demonstrate the computational efficiency and the robust modelspace convergence of our approach and compare to established approximate methods, such as the Random Phase Approximation, shedding new light on their deficiencies.
Crosslists for Thu, 21 Sep 17
 [5] arXiv:1611.06901 (crosslist from heplat) [pdf, other]

Title: Gluon momentum fraction of the nucleon from lattice QCDAuthors: Constantia Alexandrou, Martha Constantinou, Kyriakos Hadjiyiannakou, Karl Jansen, Haralambos Panagopoulos, Christian WieseComments: 16 pages, 2 Table, 8 Figures, Version accepted for publication in Phys. Rev. DJournalref: Phys. Rev. D 96, 054503 (2017)Subjects: High Energy Physics  Lattice (heplat); High Energy Physics  Experiment (hepex); High Energy Physics  Phenomenology (hepph); High Energy Physics  Theory (hepth); Nuclear Theory (nuclth)
We perform a direct calculation of the gluon momentum fraction of the nucleon using maximally twisted mass fermion ensembles with $N_f=2+1+1$ flavors at a pion mass of about $370\,\mathrm{MeV}$ and a lattice spacing of $a\approx 0.082\,\mathrm{fm}$ and with $N_f=2$ flavors at the physical pion mass and a lattice spacing of $a\approx 0.093\,\mathrm{fm}$. In the definition of the gluon operator we employ stout smearing to obtain a statistically significant result for the bare matrix elements. In addition, we perform a lattice perturbative calculation including 2 levels of stout smearing to carry out the mixing and the renormalization of the quark and gluon operators. We find, after conversion to the $\overline{\mathrm{MS}}$ scheme at a scale of $2\,\mathrm{GeV}$: $\langle x\rangle^R_g {=} 0.284(23)(23)$ for pion mass of about $370\,\mathrm{MeV}$ and $\langle x\rangle^R_g {=} 0.283(23)(15)$ for the physical pion mass.
Replacements for Thu, 21 Sep 17
 [6] arXiv:1612.05795 (replaced) [pdf, other]

Title: What is the magnetic field distribution for the equation of state of magnetized neutron stars?Subjects: High Energy Astrophysical Phenomena (astroph.HE); Solar and Stellar Astrophysics (astroph.SR); General Relativity and Quantum Cosmology (grqc); Nuclear Theory (nuclth)
 [7] arXiv:1702.07620 (replaced) [pdf, ps, other]

Title: Probing QCD critical fluctuations from light nuclei production in relativistic heavyion collisionsComments: 6 pages, 1 figure, 2 tables. Correlations between neutron and proton density fluctuations considered and presentation improved. Accepted version to appear in PLBSubjects: Nuclear Theory (nuclth); High Energy Physics  Phenomenology (hepph); Nuclear Experiment (nuclex)
 [8] arXiv:1705.07548 (replaced) [pdf, ps, other]

Title: $K^+$nucleus elastic scattering revisited from perspective of partial restoration of chiral symmetrySubjects: Nuclear Theory (nuclth)
 [9] arXiv:1706.00258 (replaced) [pdf, ps, other]

Title: Toward a systematic strategy for defining power counting in the construction of the energy density functional theoryComments: 24 pages, 12 figures. Published versionJournalref: Phys. Rev. C 96 034318 (2017)Subjects: Nuclear Theory (nuclth)
 [10] arXiv:1706.07376 (replaced) [pdf, other]

Title: Regge phenomenology in $π^0$ and $η$ photoproductionComments: 11 pages, 10 figuresJournalref: Phys. Rev. C 96, 035207 (2017)Subjects: High Energy Physics  Phenomenology (hepph); Nuclear Experiment (nuclex); Nuclear Theory (nuclth)
 [11] arXiv:1708.00536 (replaced) [pdf, other]

Title: Highprecision $Q_{EC}$value measurement of the superallowed $β^+$ emitter $^{22}$Mg and an evaluation of the $A=22$ isobaric tripletAuthors: M.P. Reiter, K.G. Leach, O. M. Drozdowski, S.R. Stroberg, J.D. Holt, C. Andreoiu, C. Babcock, B. Barquest, M. Brodeur, A. Finlay, M. Foster, A.T. Gallant, G. Gwinner, R. Klawitter, B. Kootte, A.A Kwiatkowski, Y. Lan, D. Lascar, E. Leistenschneider, A. Lennarz, S. Paul, R. Steinbrügge, R.I. Thompson, M. Wieser, J. DillingComments: Submitted to Physical Review CSubjects: Nuclear Experiment (nuclex); Nuclear Theory (nuclth)
 [12] arXiv:1708.04437 (replaced) [pdf, ps, other]

Title: From quark and nucleon correlations to discrete symmetry and clustering in nucleiAuthors: Genis MusulmanbekovComments: 12 pages, 4 figures. Presented at Int. Symp. "Exotic Nuclei  Exon 2016"Subjects: Nuclear Theory (nuclth)
 [13] arXiv:1709.04268 (replaced) [pdf, ps, other]

Title: Strong and radiative decays of the lowlying $S$ and $P$wave singly heavy baryonsComments: 19 pages, 8 figures, 10 tablesSubjects: High Energy Physics  Phenomenology (hepph); High Energy Physics  Experiment (hepex); Nuclear Theory (nuclth)
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