Nuclear Theory·nucl-th

Monday·May 13, 2019

8 papers—3 primary·5 cross-listed

01
[Submitted on 9 May 2019]
Comparaison between Coulomb and Hulthèn potentials within Bohr Hamiltonian for $γ$ -rigid nuclei in the presence of minimal length
M. Chabab · A. El Batoul · M. Hamzavi · A. Lahbas · I. Moumene · M. Oulne
In this work we solve the Schrödinger equation for Bohr Hamiltonian with Coulomb and Hulthén potentials within the formalism of minimal length in order to obtain analytical expressions for the energy eigenvalues and eigenfunctions by means of asymptotic iteration method. The obtained formulas of the energy spectrum and wave functions, are used to calculate excitation energies and transition rates of $γ$ -rigid nuclei and compared with the experimental data at the shape phase critical point X(3) in nuclei.
Comments:
8 pages, 1 Figure, LaTeX, contribution to the Proceedings of the 37-th International Workshop on Nuclear Theory (IWNT-37), Rila Mountains, Bulgaria, June 25-July 1, 2018. Editors: M. Gaidarov and N. Minkov, Published by Heron Press Ltd., Sofia, Bulgaria, ISSN 1313-2822
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1905.03799 [pdf]
Nucl.Theor.(2018)·0 citations
02
[Submitted on 10 May 2019]
Lattice QCD Study of the Nucleon-Charmonium Interaction
Takuya Sugiura🇯🇵 · Yoichi Ikeda🇯🇵 · Noriyoshi Ishii🇯🇵
The $J / ψ$ -nucleon interaction is studied by lattice QCD calculations. At the leading order of the derivative expansion, the interaction consists of four terms: the central, the spin-spin, and two types of tensor forces. We determine these spin-dependent forces quantitatively by using the time-dependent HAL QCD method. We find that the spin-spin force is the main cause of the hyperfine splitting between the $J = 1/2$ and the $J = 3/2$ states, while the two tensor forces have much smaller effects on the S-wave scattering processes.
Comments:
5 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Lattice (hep-lat)
arXiv:
1905.03934 [pdf]
JPS Conf.Proc.(2019)·4 citations
03
[Submitted on 10 May 2019]
Dense Baryonic Matter and Strangeness in Neutron Stars
Wolfram Weise🇩🇪
Recent developments of chiral effective field theory (ChEFT) applications to nuclear and neutron matter are summarized, with special emphasis on a (non-perturbative) extension using functional renormalisation group methods. Topics include: nuclear thermodynamics, extrapolations to dense baryonic matter and constraints from neutron star observables. Hyperon-nuclear interactions derived from SU(3) will be discussed with reference to the "hyperon puzzle" in neutron star matter.
Comments:
17 pages, 7 figures; invited talk at the Int. Conf. on Quarks and Nuclear Physics (QNP 2018), Tsukuba, Japan; to appear in JPS Conf. Proc
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1905.03955 [pdf]
JPS Conf.Proc.(2019)·15 citations
04
[Submitted on 9 May 2019] (cross-list from hep-ph)
Strange quark suppression from a simultaneous Monte Carlo analysis of parton distributions and fragmentation functions
N. Sato🇺🇸 · C. Andres🇺🇸 · J. J. Ethier🇳🇱 · W. Melnitchouk🇺🇸
We perform the first simultaneous extraction of unpolarized parton distributions and fragmentation functions from a Monte Carlo analysis of inclusive and semi-inclusive deep-inelastic scattering, Drell-Yan lepton-pair production, and single-inclusive $e^{+} e^{-}$ annihilation data. We use data resampling techniques to thoroughly explore the Bayesian posterior distribution of the extracted functions, and use $k$ -means clustering on the parameter samples to identify the configurations that give the best description across all reactions. Inclusion of the semi-inclusive data reveals a strong suppression of the strange quark distribution at parton momentum fractions $x ≳ 0.01$ , in contrast with the ATLAS observation of enhanced strangeness in $W^{\pm}$ and $Z$ production at the LHC. Our study reveals significant correlations between the strange quark density and the strange $\to$ kaon fragmentation function needed to simultaneously describe semi-inclusive $K^{\pm}$ production data from COMPASS and inclusive $K^{\pm}$ spectra in $e^{+} e^{-}$ annihilation from ALEPH and SLD, as well as between the strange and light antiquark densities in the proton.
Comments:
6 pages, 4 figures; version to appear in Phys. Rev. D
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1905.03788 [pdf]
PRD(2020)·118 citations
05
[Submitted on 9 May 2019] (cross-list from hep-ph)
Production of exotic tetraquarks $QQ q ˉ q ˉ$ in heavy-ion collisions at the LHC
C. E. Fontoura🇧🇷 · G. Krein🇧🇷 · A. Valcarce🇪🇸 · J. Vijande🇪🇸
We investigate the production of exotic tetraquarks, $QQ q ˉ q ˉ \equiv T_{QQ}$ ( $Q = c$ or $b$ and $q = u$ or $d$ ), in relativistic heavy-ion collisions using the quark coalescence model. The $T_{QQ}$ yield is given by the overlap of the density matrix of the constituents in the emission source with the Wigner function of the produced tetraquark. The tetraquark wave function is obtained from exact solutions of the four-body problem using realistic constituent models. The production yields are typically one order of magnitude smaller than previous estimations based on simplified wave functions for the tetraquarks. We also evaluate the consequences of the partial restoration of chiral symmetry at the hadronization temperature on the coalescence probability. Such effects, in addition to increasing the stability of the tetraquarks, lead to an enhancement of the production yields, pointing towards an excellent discovery potential in forthcoming experiments. We discuss further consequences of our findings for the search of exotic tetraquarks in central Pb+Pb collisions at the LHC.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1905.03877 [pdf]
PRD(2019)·38 citations
06
[Submitted on 10 May 2019] (cross-list from hep-ph)
The hidden charm pentaquark states and $Σ_{c} D ˉ^{(*)}$ interaction in chiral perturbation theory
Lu Meng🇨🇳 · Bo Wang🇨🇳 · Guang-Juan Wang🇨🇳 · Shi-Lin Zhu🇨🇳
In this work, we employ the heavy hadron chiral perturbation theory (HHChPT) to calculate the $Σ_{c} D ˉ^{(*)}$ potentials to the next-to-leading order. The contact, the one-pion exchange and the two-pion exchange interactions are included. Besides, the mass splittings between the heavy quark spin symmetry (HQSS) multiplets are kept in calculations. Our result shows that neglecting the heavy quark symmetry (HQS) violation effect may be misleading to predict the potentials between the charmed hadrons. We perform numerical analysis with three scenarios. In the first scenario, we relate the low-energy constants (LECs) in the contact terms of $Σ_{c} D ˉ^{(*)}$ to those of nucleon systems, and reproduce the $P_{c} (4312)$ and $P_{c} (4440)$ as loosely bound states. In the second scenario, we vary the unknown LECs and find a small parameter region in which $P_{c} (4312)$ , $P_{c} (4440)$ and $P_{c} (4457)$ can coexist as molecular states. In the third scenario, we include the coupled-channel effect on the basis of scenario II, and notice that the three $P_{c}$ states can be reproduced as molecular states simultaneously in a large region of parameters. Our analytical results can be used for the chiral extrapolations in lattice QCD. With the lattice QCD results in the future as inputs, the identification of the $P_{c}$ states and predictions for other systems would be more reliable.
Comments:
16 pages, 12 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
1905.04113 [pdf]
PRD(2019)·139 citations
07
[Submitted on 10 May 2019] (cross-list from nucl-ex)
Is the structure of 42Si understood?
A. Gade · B.A. Brown · J. A. Tostevin · D. Bazin · P. C. Bender · C.M. Campbell · H. L. Crawford · B. Elman · K. W. Kemper · B. Longfellow · E. Lunderberg · D. Rhodes · D. Weisshaar
A more detailed test of the implementation of nuclear forces that drive shell evolution in the pivotal nucleus \nuc{42}{Si} -- going beyond earlier comparisons of excited-state energies -- is important. The two leading shell-model effective interactions, SDPF-MU and SDPF-U-Si, both of which reproduce the low-lying \nuc{42}{Si}( $2_{1}^{+}$ ) energy, but whose predictions for other observables differ significantly, are interrogated by the population of states in neutron-rich \nuc{42}{Si} with a one-proton removal reaction from \nuc{43}{P} projectiles at 81~MeV/nucleon. The measured cross sections to the individual \nuc{42}{Si} final states are compared to calculations that combine eikonal reaction dynamics with these shell-model nuclear structure overlaps. The differences in the two shell-model descriptions are examined and linked to predicted low-lying excited $0^{+}$ states and shape coexistence. Based on the present data, which are in better agreement with the SDPF-MU calculations, the state observed at 2150(13)~keV in \nuc{42}{Si} is proposed to be the ( $0_{2}^{+}$ ) level.
Comments:
accepted in Physical Review Letters
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1905.04142 [pdf]
PRL(2019)·36 citations
08
[Submitted on 10 May 2019] (cross-list from hep-ph)
Internal particle width effects on the the triangle singularity mechanism in the study of the $η (1405)$ and $η (1475)$ puzzle
Meng-Chuan Du🇨🇳 · Qiang Zhao🇨🇳
In this article, the analyticity of triangle loop integral with complex masses of internal particles is discussed in a new perspective, base on which we obtain the explicit width dependence of the absorptive part of the triangle amplitude. We reanalyze the decay pattern of $η (1405/1475)$ with the width effects included in the triangle singularity (TS) mechanism. Based on the present experimental information, we provide a self-consistent description of the $K K ˉ π$ , $η π π$ , and $3 π$ decay channels for $η (1405/1475)$ . Our results confirm the claim that the TS mechanism plays a decisive role in the understanding of the $η (1405)$ and $η (1475)$ puzzle. Namely, the observed differences of $η$ resonances within the mass region of $1.40 \sim 1.48$ GeV are originated from the same state. For the isospin violated process $J / ψ \to γ η (1405/1475) \to f_{0} (980) π \to 3 π$ , we identify an additional contribution to the $a_{0} (980) - f_{0} (980)$ mixing via the TS mechanism.
Comments:
28 pages, 13 figures, an error is corrected and Figs. 11, 12, 13 are updated. The main conclusion is unchanged. Revised version accepted by Phys. Rev. D
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1905.04207 [pdf]
PRD(2019)·45 citations

Affiliations

first authorsco-authorsvia INSPIRE