5
5.0
Jun 29, 2018
06/18
by
H. Müther; O. A. Rubtsova; V. I. Kukulin; V. N. Pomerantsev
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The Lippmann-Schwinger equation for the nucleon-nucleon $t$-matrix as well as the corresponding Bethe-Goldstone equation to determine the Brueckner reaction matrix in nuclear matter are reformulated in terms of the resolvents for the total two-nucleon Hamiltonians defined in free space and in medium correspondingly. This allows to find solutions at many energies simultaneously by using the respective Hamiltonian matrix diagonalization in the stationary wave packet basis. Among other important...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1607.01694
4
4.0
Jun 29, 2018
06/18
by
Ronghua He; Jing Qian; Jianyi Chen; Qingxin Wu; Lei Huo
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Single particle transverse mass spectra and HBT radii of identical pion and identical kaon are analyzed with a blast-wave parametrization under the assumptions local thermal equilibrium and transverse expansion. Under the assumptions, temperature parameter $T$ and transverse expansion rapidity $\rho$ are sensitive to the shapes of transverse mass $m_\text T$ spectrum and HBT radius $R_\text{s}(K_\text T)$. Negative and positive correlations between $T$ and $\rho$ are observed by fitting...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1608.04068
4
4.0
Jun 29, 2018
06/18
by
Chun Shen; Jean-François Paquet; Gabriel S. Denicol; Sangyong Jeon; Charles Gale
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eye 4
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Collective behaviour has been observed in hadronic measurements of high multiplicity proton+lead collisions at the Large Hadron Collider (LHC), as well as in (proton, deuteron, helium-3)+gold collisions at the Relativistic Heavy-Ion Collider (RHIC). To better understand the evolution dynamics and the properties of the matter created in these small systems, a systematic study of the soft hadronic observables together with electromagnetic radiation from these collisions is performed, using a...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1609.02590
4
4.0
Jun 29, 2018
06/18
by
Isaac Vidana; Artur Polls; Victoria Durant
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Using the Hellmann--Feynman theorem we analyze the contribution of the different terms of the nucleon-nucleon interaction to the spin symmetry energy of neutron matter. The analysis is performed within the microscopic Brueckner--Hartree--Fock approach using the Argonne V18 realistic potential plus the Urbana IX three-body force. The main contribution to the spin-symmetry energy of neutron matter comes from the S=0 channel, acting only in the non-polarized neutron matter, in particular the...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1609.03005
6
6.0
Jun 29, 2018
06/18
by
E. E. Saperstein; M. Baldo; S. S. Pankratov; S. V. Tolokonnikov
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A method is presented to evaluate the particle-phonon coupling (PC) corrections to the single-particle energies (SPEs) in semi-magic nuclei. In such nuclei always there is a collective low-lying $2^+$ phonon, and a strong mixture of single-particle and particle-phonon states often occurs. As in magic nuclei, the so-called $g^2_L$ approximation, where $g_L$ is the vertex of the $L$-phonon creation, can be used for finding the PC correction $\delta \Sigma^{\rm PC}(\varepsilon)$ to the initial...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1609.03761
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17
Jun 30, 2018
06/18
by
Yue Shi; D. E. Ward; B. G. Carlsson; J. Dobaczewski; W. Nazarewicz; I. Ragnarsson; D. Rudolph
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A recent high-resolution $\alpha$, $X$-ray, and $\gamma$-ray coincidence-spectroscopy experiment offered first glimpse of excitation schemes of isotopes along $\alpha$-decay chains of $Z=115$. To understand these observations and to make predictions about shell structure of superheavy nuclei below $^{288}115$, we employ two complementary mean-field models: self-consistent Skyrme Energy Density Functional approach and the macroscopic-microscopic Nilsson model. We discuss the spectroscopic...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1401.7959
7
7.0
Jun 30, 2018
06/18
by
Y. Wunderlich
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The complete experiment problem for photoproduction of single pseudoscalar mesons is reviewed briefly. If this problem is investigated in the context of a truncated partial wave analysis, the chance emerges to obtain a unique multipole solution measuring less polarization observables than demanded by the classical solution of the problem that is formulated in terms of spin amplitudes.
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1402.5316
4
4.0
Jun 30, 2018
06/18
by
Sonia Bacca; Nir Barnea; Winfried Leidemann; Giuseppina Orlandini
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The isoscalar monopole excitation of 4He is studied within a few-body ab initio approach. We consider the transition density to the low-lying and narrow 0+ resonance, as well as various sum rules and the strength energy distribution itself at different momentum transfers q. Realistic nuclear forces of chiral and phenomenological nature are employed. Various indications for a collective breathing mode are found: i) the specific shape of the transition density, ii) the high degree of exhaustion...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1403.6961
7
7.0
Jun 30, 2018
06/18
by
X. Liu; W. Lin; R. Wada; M. Huang; Z. Chen; G. Q. Xiao; S. Zhang; X. Jin; J. Liu; F. Shi; P. Ren; H. Zheng; J. B. Natowitz; A. Bonasera
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For central collisions of $^{40}$Ca $+ ^{40}$Ca at 35 MeV/nucleon, the density and temperature of a fragmenting source have been evaluated in a self-consistent manner using the ratio of the symmetry energy coefficient relative to the temperature, $a_{sym}/T$, extracted from the yields of primary isotopes produced in antisymmetrized molecular dynamics (AMD) simulations. The $a_{sym}/T$ values are extracted from all isotope yields using an improved method based on the Modified Fisher Model (MFM)....
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1404.5830
4
4.0
Jun 30, 2018
06/18
by
Bo Zhou; Yasuro Funaki; Akihiro Tohsaki; Hisashi Horiuchi; Zhongzhou Ren
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It is shown that the single $0^+$ THSR (Tohsaki-Horiuchi-Schuck-R\"{o}pke) wave function which is extended to include 2$\alpha$ correlation is almost completely equivalent to the 3$\alpha$ wave function obtained as the full solution of 3$\alpha$ cluster model. Their squared overlap is as high as 98\% while it is 93\% if the 2$\alpha$ correlation is not included. This result implies that, by incorporating the 2$\alpha$ correlation in the 3$\alpha$ model, the ground state of $^{12}$C is...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1408.2920
15
15
Jun 27, 2018
06/18
by
A. K. Rhine Kumar; P. Arumugam; N. Dinh Dang
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Apart from the higher limits of isospin and temperature, the properties of atomic nuclei are intriguing and less explored at the limits of lowest but finite temperatures. At very low temperatures there is a strong interplay between the shell (quantal fluctuations), statistical (thermal fluctuations), and residual pairing effects as evidenced from the studies on giant dipole resonance (GDR). In our recent work [Phys. Rev. C \textbf{90}, 044308 (2014)], we have outlined some of our results from a...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1504.01246
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12
Jun 27, 2018
06/18
by
Myagmarjav Odsuren; Yuma Kikuchi; Takayuki Myo; Masayuki Aikawa; Kiyoshi Kato
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We study the character of the first excited 1/2^{+} state of {9}^Be, which is observed as a low-lying sharp peak in the cross section of 9^Be({\gamma},n)2{\alpha} just above the {8}^Be+n threshold. Using the {\alpha}+{\alpha}+n three-body model, we describe the ground and excited unbound states of {9}^Be above the {\alpha}+{\alpha}+n threshold. Applying the complex scaling method to the three-body model, we find no 1/2^{+} resonant solutions, while the low-lying peak in the photodisintegration...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1505.02353
9
9.0
Jun 28, 2018
06/18
by
P. Buganu; R. Budaca
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eye 9
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The equation of the Bohr-Mottelson Hamiltonian with a sextic oscillator potential is solved for $\gamma$-rigid prolate nuclei. The associated shape phase space is reduced to three variables which are exactly separated. The angular equation has the spherical harmonic functions as solutions, while the $\beta$ equation is brought to the quasi-exactly solvable case of the sextic oscillator potential with a centrifugal barrier. The energies and the corresponding wave functions are given in closed...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1508.00728
10
10.0
Jun 28, 2018
06/18
by
M. A. Caprio; P. Maris; J. P. Vary; R. Smith
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Through ab initio approaches in nuclear theory, we may now seek to quantitatively understand the wealth of nuclear collective phenomena starting from the underlying internucleon interactions. No-core configuration interaction (NCCI) calculations for p-shell nuclei give rise to rotational bands, as evidenced by rotational patterns for excitation energies, electromagnetic moments, and electromagnetic transitions. In this review, NCCI calculations of 7-9Be are used to illustrate and explore ab...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1509.00102
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11
Jun 28, 2018
06/18
by
A. E. Lovell; F. M. Nunes; I. J. Thompson
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Recently, the first example of two-neutron decay from the ground state of an unbound nucleus, $^{16}$Be, was seen. Three-body methods are ideal for exactly treating the degrees of freedom important for these decays. Using a basis expansion over hyperspherical harmonics and the hyperspherical R-matrix method, we construct a realistic model of $^{16}$Be in order to investigate its decay mode and the role of the two-neutron interaction. The neutron-$^{14}$Be interaction is constrained using shell...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1509.01193
5
5.0
Jun 28, 2018
06/18
by
X. Roca-Maza; X. Viñas; M. Centelles; B. K. Agrawal; G. Colo'; N. Paar; J. Piekarewicz; D. Vretenar
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The information on the symmetry energy and its density dependence is deduced by comparing the available data on the electric dipole polarizability $\alpha_D$ of ${}^{68}$Ni, ${}^{120}$Sn, and ${}^{208}$Pb with the predictions of the Random Phase Approximation, using a representative set of nuclear energy density functionals. The calculated values of $\alpha_D$ are used to validate different correlations involving $\alpha_D$, the symmetry energy at the saturation density $J$, the corresponding...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1510.01874
4
4.0
Jun 28, 2018
06/18
by
Marlene Nahrgang
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eye 4
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Heavy-flavor observables are valuable probes of the quark-gluon plasma, which is expected to be produced in ultrarelativistic heavy-ion collisions. These experiments offer the unique opportunity to study strongly interacting matter at high temperatures and densities in the laboratory. In this overview talk I will summarize the current theoretical status of heavy-flavor production and suppression in heavy-ion collisions and discuss open challenges.
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1510.03627
7
7.0
Jun 29, 2018
06/18
by
Bhoomika Maheshwari; Ashok Kumar Jain
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eye 7
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In our recent paper [Phys. Lett. B 753, (2016) 122], we have shown that both the odd and even tensor electric transition probabilities exhibit similar behavior within the generalized seniority scheme in a multi-j environment. This microscopic approach was used to show for the first time the occurrence of seniority isomers in the $ {13}^-$ isomers of Sn-isotopes, which decay by odd tensor $E1$ transition to the same seniority ($\Delta v = 0$) state. In this letter, we extend our studies to odd...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1601.07651
8
8.0
Jun 29, 2018
06/18
by
Jie Meng; Pengwei Zhao
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eye 8
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Excitations of chiral rotation observed in triaxial nuclei and magnetic and/or antimagnetic rotations seen in near-spherical nuclei have attracted a lot of attention. Unlike conventional rotation in well-deformed or superdeformed nuclei, here the rotational axis is not necessary coinciding with any principal axis of the nuclear density distribution. Thus, tilted axis cranking is mandatory to describe these excitations self-consistently in the framework of covariant density functional theory...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1604.02213
7
7.0
Jun 29, 2018
06/18
by
Ch. Constantinou; M. A. Caprio; J. P. Vary; P. Maris
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eye 7
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Ab initio calculations of nuclei face the challenge of simultaneously describing strong short-range internucleon correlations and the long-range properties of weakly-bound halo nucleons. Natural orbitals, which diagonalize the one-body density matrix, provide a basis which is better matched to the physical structure of the many-body wave function. We demonstrate that the use of natural orbitals significantly improves convergence for ab initio no-core configuration interaction calculations of...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1605.04976
4
4.0
Jun 29, 2018
06/18
by
T. Haverinen; M. Kortelainen
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eye 4
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The parameters of the nuclear energy density have to be adjusted to experimental data. As a result they carry certain uncertainty which then propagates to calculated values of observables. In the present work we quantify the statistical uncertainties of binding energies, proton quadrupole moments, and proton matter radius for three UNEDF Skyrme energy density functionals by taking advantage of the knowledge of the model parameter uncertainties. We find that the uncertainty of UNEDF models...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1611.00597
6
6.0
Jun 29, 2018
06/18
by
V. D. Rusov; V. A. Tarasov; S. A. Chernezhenko; A. A. Kakaev; V. P. Smolyar
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In this paper we present the analytical expression for the neutron scattering law for an isotropic source of neutrons, obtained within the framework of the gas model with the temperature of the moderating medium as a parameter. The obtained scattering law is based on the solution of the kinematic problem of elastic scattering of neutrons on nuclei in the L-system in the general case. I.e. both the neutron and the nucleus possess the arbitrary velocity vectors in the L-system. For the new...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1612.06838
7
7.0
Jun 30, 2018
06/18
by
Ying Zhang; Ying Chen; Jie Meng; Peter Ring
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eye 7
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The influence of pairing correlations on the neutron root mean square (rms) radius of nuclei is investigated in the framework of self-consistent Skyrme Hartree-Fock-Bogoliubov calculations. The continuum is treated appropriately by the Green's function techniques. As an example the nucleus $^{124}$Zr is treated for a varying strength of pairing correlations. We find that, as the pairing strength increases, the neutron rms radius first shrinks, reaches a minimum and beyond this point it expands...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1701.04510
8
8.0
Jun 30, 2018
06/18
by
H. S. Sahoo; R. N. Mishra; P. K. Panda; N. Barik
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The possibility of the appearance of $\Delta$ isobars in neutron star matter and the so called {\it $\Delta$ puzzle} is studied in a modified quark meson coupling model where the confining interaction for quarks inside a baryon is represented by a phenomenological average potential in an equally mixed scalar-vector harmonic form. The hadron-hadron interaction in nuclear matter is then realized by introducing additional quark couplings to $\sigma$, $\omega$, and $\rho$ mesons through mean-field...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1702.02310
6
6.0
Jun 30, 2018
06/18
by
Yingru Xu; Marlene Nahrgang; Jonah E. Bernhard; Shanshan Cao; Steffen A. Bass
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Using a Bayesian model-to-data analysis, we estimate the temperature dependence of the heavy quark diffusion coefficients by calibrating to the experimental data of $D$-meson $R_{\mathrm{AA}}$ and $v_2$ in AuAu collisions ($\sqrt{s_{NN}}=200$ GeV) and PbPb collisions ($\sqrt{s_{NN}}=2.76$ TeV)~\cite{Xie:2016iwq}. The spatial diffusion coefficient $D_s2\pi T$ is found to be mostly constraint around $(1.3-1.5) T_c$ and is compatible with lattice QCD calculations. We demonstrate the capability of...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1704.07800
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17
Jun 28, 2018
06/18
by
J. Barea; J. Kotila; F. Iachello
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eye 17
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Neutrinoless double-$\beta$ decay is of fundamental importance for determining the neutrino mass. Although double electron ($\beta^-\beta^-$) decay is the most promising mode, in very recent years interest in double positron ($\beta^+\beta^+$) decay, positron emitting electron capture ($EC\beta^+$), and double electron capture ($ECEC$) has been renewed. We present here results of a calculation of nuclear matrix elements for neutrinoless double-$\beta^+$ decay and positron emitting electron...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1509.05157
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9.0
Jun 29, 2018
06/18
by
Raul A. Herrera; Calvin W. Johnson
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Background: Symmetries are a powerful way to characterize nuclear wave functions. A true dynamical symmetry, where the Hamiltonian is block-diagonal in subspaces defined by the group, is rare. More likely is a quasidynamical symmetry: states with different quantum numbers (i.e. angular momentum) nonetheless sharing similar group-theoretical decompositions. Purpose: We use group-theoretical decomposition to investigate backbending, an abrupt change in the moment of inertia along the yrast line,...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1607.00887
4
4.0
Jun 30, 2018
06/18
by
A. Ekström; B. D. Carlsson; K. A. Wendt; C. Forssén; M. Hjorth-Jensen; R. Machleidt; S. M. Wild
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We have quantified the statistical uncertainties of the low-energy coupling-constants (LECs) of an optimized nucleon-nucleon (NN) interaction from chiral effective field theory ($\chi$EFT) at next-to-next-to-leading order (NNLO). In addition, we have propagated the impact of the uncertainties of the LECs to two-nucleon scattering phase shifts, effective range parameters, and deuteron observables.
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1406.6895
4
4.0
Jun 30, 2018
06/18
by
Wen-Mei Guo; Gao-Chan Yong; Wei Zuo
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Based on the isospin-dependent Boltzmann-Uehling-Uhlenbeck(IBUU04) transport model, we explored effects of in-medium $NN$ elastic scattering cross section and nuclear symmetry energy on the sub-threshold pion production in $^{132}Sn+^{124}Sn$ reaction. We find that with decrease of incident beam energy, effects of in-medium $NN$ elastic scattering cross section on the $\pi^{-}/\pi^{+}$ ratio are larger than that of the symmetry energy although the latter may be also larger. While keeping the...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1407.0432
5
5.0
Jun 30, 2018
06/18
by
G. Röpke; P. Schuck; Bo Zhou; Y. Funaki; H. Horiuchi; Zhongzhou Ren; A. Tohsaki; Chang Xu; T. Yamada
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An effective $\alpha$ particle equation is derived for cases where an $\alpha$ particle is formed on top of a doubly magic nucleus. As an example, we consider $^{212}$Po with the $\alpha$ on top of the $^{208}$ Pb core. We will consider the core nucleus infinitely heavy, so that the $\alpha$ particle moves with respect to a fixed center, i.e., recoil effects are neglected. The fully quantal solution of the problem is discussed. The approach is inspired by the THSR...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1407.0510
5
5.0
Jun 30, 2018
06/18
by
K. Amos; L. Canton; P. R. Fraser; S. Karataglidis; J. P. Svenne; D. van der Knijff
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A multi-channel algebraic scattering (MCAS) method has been used to solve coupled sets of Lippmann-Schwinger equations for $\alpha$+nucleus systems to find spectra of the compound systems. Low energy spectra for ${}^{12}$C, ${}^{16}$O, and ${}^{20}$Ne are found with the systems considered as the coupling of an $\alpha$ particle with low-excitation states of the core nuclei, ${}^8$Be, ${}^{12}$C, and ${}^{16}$O, respectively. Collective models have been used to define the matrices of interacting...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1410.7507
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12
Jun 27, 2018
06/18
by
Z. Y. Wang; Z. M. Niu; Y. F. Niu; J. Y. Guo
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The self-consistent proton-neutron quasiparticle random phase approximation approach is employed to calculate $\beta$-decay half-lives of neutron-rich even-even nuclei with $8\leqslant Z \leqslant 30$. A newly proposed nonlinear point-coupling effective interaction PC-PK1 is used in the calculations. It is found that the isoscalar proton-neutron pairing interaction can significantly reduce $\beta$-decay half-lives. With an isospin-dependent isoscalar proton-neutron pairing strength, our results...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1503.01222
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16
Jun 27, 2018
06/18
by
Alexander Volya; Hans A. Weidenmüller; Vladimir Zelevinsky
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Experimental evidence has recently put the validity of the Porter-Thomas distribution (PTD) for partial neutron widths into question. We identify two terms in the effective Hamiltonian that violate orthogonal invariance (the basis for the PTD). Both are due to the coupling to the decay channels. We show that realistic estimates for the coupling to the neutron channel and for non-statistical gamma decays yield significant modifications of the PTD.
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1504.06771
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8.0
Jun 27, 2018
06/18
by
Yusuke Tanimura; Denis Lacroix; Guillaume Scamps
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Given a set of collective variables, a method is proposed to obtain the associated conjugated collective momenta and masses starting from a microscopic time-dependent mean-field theory. The construction of pairs of conjugated variables is the first step to bridge microscopic and macroscopic approaches. The method is versatile and can be applied to study a large class of nuclear processes. An illustration is given here with the fission of $^{258}$Fm. Using the quadrupole moment and eventually...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1505.05647
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7.0
Jun 30, 2018
06/18
by
Noël Martin; Michael Urban
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We study collective excitations in a superfluid neutron gas at zero temperature within the quasiparticle random phase approximation. The particle-hole residual interaction is obtained from a Skyrme functional, while a separable interaction is used in the pairing channel which gives a realistic density dependence of the pairing gap. In accordance with the Goldstone theorem, we find an ungapped collective mode (analogous to the Bogoliubov-Anderson mode). At low momentum, its dispersion relation...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1406.0335
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5.0
Jun 30, 2018
06/18
by
Koichi Sato; Jacek Dobaczewski; Takashi Nakatsukasa; Wojciech Satuła
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We have performed calculations based on the Skyrme energy density functional (EDF) that includes arbitrary mixing between protons and neutrons. In this framework, single-particle states are generalized as mixtures of proton and neutron components. The model assumes that the Skyrme EDF is invariant under the rotation in isospin space and the Coulomb force is the only source of the isospin symmetry breaking. To control the isospin of the system, we employ the isocranking method, which is...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1410.2691
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6.0
Jun 30, 2018
06/18
by
H. G. Ganev
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The low-lying spectra including the first few excited positive and negative parity bands of some heavy even-even nuclei from the rare earth and actinide mass regions are investigated within the framework of the symplectic Interacting Vector Boson Model with Sp(12,$R$) dynamical symmetry group. Symplectic dynamical symmetries allow the change of the number of excitation quanta or phonons building the collective states providing for larger representation spaces and richer subalgebraic structures...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1409.1844
6
6.0
Jun 28, 2018
06/18
by
P. D. Stevenson
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The time-dependent version of nuclear density functional theory, using functionals derived from Skyrme interactions, is able to approximately describe nuclear dynamics. We present time-dependent results of calculations of dipole resonances, concentrating on excitations of valence neutrons against a proton plus neutron core in the neutron-rich doubly-magic $^{132}$Sn nucleus, and results of collision dynamics, highlighting potential routes to ternary fusion, with the example of a collision of...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1510.03017
3
3.0
Jun 30, 2018
06/18
by
Slawomir Wycech; Wojciech Krzemien
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Collisions in a system of two particles at energies close to a bound state in different channels are discussed. Next, the bound state decays into a third coupled channel. A phenomenological approach to dd->pi-p3He reaction is presented.
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1401.0747
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4.0
Jun 30, 2018
06/18
by
Min He; Rainer J. Fries; Ralf Rapp
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Employing nonperturbative transport coefficients for heavy-flavor (HF) diffusion through quark-gluon plasma (QGP), hadronization and hadronic matter, we compute $D$- and $B$-meson observables in Pb+Pb ($\sqrt{s}$=2.76\,TeV) collisions at the LHC. Elastic heavy-quark scattering in the QGP is evaluated within a thermodynamic $T$-matrix approach, generating resonances close to the critical temperature which are utilized for recombination into $D$ and $B$ mesons, followed by hadronic diffusion...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1401.3817
3
3.0
Jun 30, 2018
06/18
by
Chun-Wang Ma; Shan-Sha n Wang; Yan-Li Zhang; Hui-Ling Wei
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The residue Coulomb interaction (RCI), which affects the results of symmetry energy of neutron-rich nucleus in isobaric yield ratio (IYR) methods, is difficult to be determined. Four RCI approximations are investigated: (1) the M1--RCI adopting the $a_{c}/T$ (the ratio of Coulomb energy coefficient to temperature) determined from the IYR of mirror-nuclei fragment; (2) the M2--RCI by fitting the difference between IYRs; (3) the M3--RCI by adopting the standard Coulomb energy at a temperature...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1402.5493
3
3.0
Jun 30, 2018
06/18
by
Micah D Schuster; Sofia Quaglioni; Calvin W. Johnson; Eric D. Jurgenson; Petr Navratil
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The past two decades have seen a revolution in ab initio calculations of nuclear properties. One key element has been the development of a rigorous effective interaction theory, applying unitary transformations to soften the nuclear Hamiltonian and hence accelerate the convergence as a function of the model space size. For consistency, however, one ought to apply the same transformation to other operators when calculating transitions and mean values from the eigenstates of the renormalized...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1402.7106
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3.0
Jun 28, 2018
06/18
by
Ron Workman; Alfred Svarc
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Resonances are extracted from a number of energy-dependent and single-energy fits to scattering data. The influence of recent, precise EPECUR data is investigated. Results for the single-energy fits are derived using the L+P method of analysis and are compared to those obtained using contour integration applied to the global energy-dependent fits.
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1510.08278
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4.0
Jun 28, 2018
06/18
by
Aurel Bulgac; Piotr Magierski; Kenneth J. Roche; Ionel Stetcu
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We describe the fissioning dynamics of Pu240 from a configuration in the proximity of the outer fission barrier to full scission and the formation of the fragments within an implementation of density functional theory extended to superfluid systems and real-time dynamics. The fission fragments emerge with properties similar to those determined experimentally, while the fission dynamics appears to be quite complex, with many excited shape and pairing modes. The evolution is found to be much...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1511.00738
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5.0
Jun 28, 2018
06/18
by
Vadim Rodin; O. A. Rumyantsev; M. H. Urin
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We comment on a priority claim given by the authors of Phys.Rev.C91 (2015) 6, 064311.
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1512.02466
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8.0
Jun 28, 2018
06/18
by
W. H. Dickhoff
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The ancient problem of the saturation of symmetric nuclear matter is reviewed with an update on the status of the crises that were identified at an early stage by John Clark. We discuss how the initial problem with variational calculations providing more binding than the two hole-line contribution for the same interaction was overcome by calculations including three hole-line contributions without however reproducing the empirical nuclear saturation properties. It is argued that this remaining...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1512.06793
3
3.0
Jun 29, 2018
06/18
by
N. S. Brady; T. Aumann; C. A. Bertulani; J. O. Thomas
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We study the Coulomb excitation of pygmy dipole resonances (PDR) in heavy ion reactions at 100 MeV/nucleon and above. The reactions 68Ni+197Au and 68Ni+208Pb are taken as a practical examples. Our goal is to address the question of the influence of giant resonances on the PDR as the dynamics of the collision evolves. We show that the coupling to the giant resonances affects considerably the excitation probabilities of the PDR, a result that indicates the need of an improved theoretical...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1601.06469
3
3.0
Jun 29, 2018
06/18
by
Taihua Heng; James P. Vary; Pieter Maris
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We investigate the properties of 7Li with the JISP16 and chiral NNLO_opt nucleon-nucleon interactions and 7Be with the JISP16 interaction in the ab initio no-core full configuration (NCFC) approach. We calculate selected observables that include energy spectra, point proton root-mean-square radii, electromagnetic moments and transitions. We compare our results with experimental results, where available, as well as with results obtained using nucleon-nucleon plus three-nucleon interactions. We...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1602.00156
4
4.0
Jun 29, 2018
06/18
by
Hui Li; Xin-li Sheng; Qun Wang
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We derive analytic formula for electric and magnetic fields produced by a moving charged particle in a conducting medium with the electric conductivity $\sigma$ and the chiral magnetic conductivity $\sigma_{\chi}$. We use the Green function method and assume that $\sigma_{\chi}$ is much smaller than $\sigma$. The compact algebraic expressions for electric and magnetic fields without any integrals are obtained. They recover the Lienard-Wiechert formula at vanishing conductivities. Exact...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1602.02223
3
3.0
Jun 29, 2018
06/18
by
M. A. Jafarizadeh; M. Ghapanvari; N. Fouladi; Z. Ranjbar; A. Sadighzadeh
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Solvable supersymmetric algebraic model for descriptions of the spherical to gama unstable shape- phase transition in even and odd mass nuclei is proposed. This model is based on dual algebraic structure and Richardson - Gaudin method, where the duality relations between the unitary and quasispin algebraic structures for the boson and fermion systems are extended to mixed boson- fermion system. The structure of two type of nuclear supersymmetry schemes, based on the U(6/2) and U(6/4)...
Topic: Nuclear Theory
Source: http://arxiv.org/abs/1602.06849
