Tue·Aug 30, 2016Tuesday·August 30, 2016

1. 01*

   Longitudinal Wobbling in ${}^{133}$La

   S. Biswas🇮🇳 · R. Palit🇮🇳 · S. Frauendorf🇺🇸 · U. Garg🇺🇸 · W. Li🇨🇳 · G.H. Bhat🇮🇳 · J.A. Sheikh · J. Sethi🇮🇳 · S. Saha · Purnima Singh🇫🇷 · D. Choudhury🇮🇳 · J.T. Matta🇺🇸 and 4 other authors

   Excited states of ${}^{133}$La have been investigated to search for the wobbling excitation mode in the low-spin regime. Wobbling bands with $n_{\omega }$ = 0 and 1 are identified along with the interconnecting $\Delta I$ = 1, $E2$ transitions, which are regarded as one of the characteristic features of the wobbling motion. An increase in wobbling frequency with spin implies longitudinal wobbling for ${}^{133}$La, in contrast with the case of transverse wobbling observed in ${}^{135}$Pr. This is the first observation of a longitudinal wobbling band in nuclei. The experimental observations are accounted for by calculations using the quasiparticle-triaxial-rotor (QTR) model, which attribute the appearance of longitudinal wobbling to the early alignment of a $\pi =+$ proton pair.

   nucl-exnucl-thEPJA(2019)·75 citations
2. 02*

   Baryons in the unquenched quark model

   R. Bijker🇲🇽 · S. Diaz-Gomez🇲🇽 · M.A. Lopez-Ruiz🇺🇸 · E. Santopinto🇮🇹

   In this contribution, we present the unquenched quark model as an extension of the constituent quark model that includes the effects of sea quarks via a ${}^3{P}_0$ quark-antiquark pair-creation mechanism. Particular attention is paid to the spin and flavor content of the proton, magnetic moments and $\beta$ decays of octet baryons.

   ↳ hep-phhep-exnucl-exnucl-thAIP Conf.Proc.(2016)·1 citation
3. 03*

   Geometric symmetries in light nuclei

   Roelof Bijker🇲🇽

   The algebraic cluster model is is applied to study cluster states in the nuclei 12C and 16O. The observed level sequences 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.

   ↳ nucl-thnucl-exJ.Phys.Conf.Ser.(2017)·0 citations
4. 04*

   Reconstructing parton densities at large fractional momenta

   Alessandro Bacchetta🇮🇹 · Marco Radici🇮🇹 · Barbara Pasquini🇮🇹 · Xiaonu Xiong🇮🇹

   Parton distribution functions (PDFs) are nonperturbative objects defined by nonlocal light-cone correlations. They cannot be computed directly from Quantum Chromodynamics (QCD). Using a standard lattice QCD approach, it is possible to compute moments of PDFs, which are matrix elements of local operators. Recently, an alternative approach has been proposed, based on the introduction of quasi-parton distribution functions (quasi-PDFs), which are matrix elements of equal-time spatial correlations and hence calculable on lattice. Quasi-PDFs approach standard PDFs in the limit of very large longitudinal proton momenta $P^z$. This limit is not attainable in lattice simulations, and quasi-PDFs fail to reproduce PDFs at high fractional longitudinal momenta. In this paper, we propose a method to improve the reconstruction of PDFs by combining information from quasi-PDFs and from the Mellin moments of regular PDFs. We test our method using the diquark spectator model for up and down valence distributions of both unpolarized and helicity PDFs. In the future, the method can be used to produce PDFs entirely based on lattice QCD results.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2017)·20 citations
5. 05*

   Effects of proton angular momentum alignment on the two-shears-like mechanism in ${}^{101}$Pd

   Zhen-Hua Zhang

   The recently observed possible antimagnetic rotation band in ${}^{101}$Pd is investigated by the cranked shell model with pairing correlations treated by a particle-number conserving method, in which the blocking effects are taken into account exactly. The experimental moments of inertia and reduced $B(E2)$ transition probabilities and their variations with the rotational frequency $\omega$ are well reproduced. By analyzing the $\omega$-dependence of the occupation probability of each cranked Nilsson orbital near the Fermi surface and the contributions of valence orbitals in each major shell to the total angular momentum alignment, the upbending mechanism of $\nu h_{11/2}$ in ${}^{101}$Pd is understood clearly. The proton angular momentum alignment and its influence on the two-shears-like mechanism are also discussed.

   ↳ nucl-thnucl-exPRC(2016)·20 citations
6. 06*

   Investigation of the high-spin rotational properties of the proton emitter ${}^{113}$Cs using a particle-number conserving method

   Zhen-Hua Zhang · Peng Xu🇨🇳

   The recently observed two high-spin rotational bands in the proton emitter ${}^{113}$Cs are investigated using the cranked shell model with pairing correlations treated by a particle-number conserving method, in which the Pauli blocking effects are taken into account exactly. By using the configuration assignments of band 1 ($\pi 3/2^{+}[422],\alpha =-1/2$) and band 2 ($\pi 1/2^{+}[420],\alpha =1/2$), the experimental moments of inertia and quasiparticle alignments can be well reproduced by the present calculations, which in turn strongly support these configuration assignments. Furthermore, by analyzing the occupation probability $n_{\mu }$ of each cranked Nilsson level near the Fermi surface and the contribution of each orbital to the angular momentum alignments, the backbending mechanism of these two bands is also investigated.

   ↳ nucl-thnucl-exCPC(2017)·0 citations
7. 07*

   Multilayer network analysis of nuclear reactions

   Liang Zhu · Yu-Gang Ma🇨🇳 · Qu Chen · Ding-Ding Han

   The nuclear reaction network is usually studied via precise calculation of differential equation sets, and much research interest has been focused on the characteristics of nuclides, such as half-life and size limit. In this paper, however, we adopt the methods from both multilayer and reaction networks, and obtain a distinctive view by mapping all the nuclear reactions in JINA REACLIB database into a directed network with 4 layers: neutron, proton, ${}^4$He and the remainder. The layer names correspond to reaction types decided by the currency particles consumed. This combined approach reveals that, in the remainder layer, the $\beta$-stability has high correlation with node degree difference and overlapping coefficient. Moreover, when reaction rates are considered as node strength, we find that, at lower temperatures, nuclide half-life scales reciprocally with its out-strength. The connection between physical properties and topological characteristics may help to explore the boundary of the nuclide chart.

   ↳ nucl-thnucl-exphysics.data-anSci.Rep.(2016)·4 citations
8. 08*

   $X(4140)$, $X(4270)$, $X(4500)$ and $X(4700)$ and their $cs\bar{c}\bar{s}$ tetraquark partners

   Jing Wu🇨🇳 · Yan-Rui Liu🇨🇳 · Kan Chen🇨🇳 · Xiang Liu🇨🇳 · Shi-Lin Zhu🇨🇳

   In the simple color-magnetic interaction model, we investigate possible ground $cs\bar{c}\bar{s}$ tetraquark states in the diquark-antidiquark basis. We use several methods to estimate the mass spectrum and discuss possible assignment for the $X$ states observed in the $J/\psi \varphi$ channel. We find that assigning the Belle $X(4350)$ as a $0^{++}$ tetraquark is consistent with the tetraquark interpretation for the $X(4140)$ and $X(4270)$ while the interpretation of the $X(4500)$ and $X(4700)$ needs orbital or radial excitation. There probably exist several tetraquarks around 4.3 GeV that decay into $J/\psi \varphi$ or ${\eta }_c\varphi$.

   ↳ hep-phhep-exhep-latnucl-ex+1PRD(2016)·69 citations
9. 09*

   The first self-consistent calculation of quadrupole moments of odd semi-magic nuclei accounting for phonon induced corrections

   E.E. Saperstein · S. Kamerdzhiev · D.S. Krepish · S.V. Tolokonnikov · D. Voitenkov

   The self-consistent model, developed previously to describe phonon coupling (PC) effects in magnetic moments of odd magic and semi-magic nuclei, is extended to quadrupole moments. It is based on the theory of finite Fermi systems with the use of the perturbation theory in $g_L^2$, where $g_L$ is the vertex creating the $L$-phonon. Accounting for the phonon tadpole diagrams is an important ingredient of this model. The calculation scheme is based on the Fayans energy density functional DF3-a and does not contain any adjusted parameters. The odd In and Sb isotopes are considered, which are the proton-odd neighbors of even tin nuclei. The $2_1^{+}$ phonon is taken into account which quadrupole moment is one ingredient of the calculation scheme. The corresponding values were found by us previously. Two main PC corrections, due to the phonon $Z$-factor and due to the phonon-induced interaction, have opposite signs and cancel strongly each other, leaving room for other `small' corrections, so that the resulting PC correction is much lower than the absolute values of each of two main ones. However, it remains noticeable, making the overall agreement with the data significantly better.

   ↳ nucl-thnucl-exJ.Phys.G(2017)·8 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.