Nuclear Theory·nucl-th

Tuesday·August 29, 2017

10 papers—6 primary·4 cross-listed

01
[Submitted on 26 Aug 2017]
Computation of the Binding Energies in the Inverse Problem Framework
S.Cht. Mavrodiev · M.A. Deliyergiyev
We formalized the nuclear mass problem in the inverse problem framework. This approach allows us to infer the underlying model parameters from experimental observation, rather than to predict the observations from the model parameters. The inverse problem was formulated for the numericaly generalized the semi-empirical mass formula of Bethe and von Weizsäcker. It was solved in step by step way based on the AME2012 nuclear database. The solution of the overdetermined system of nonlinear equations has been obtained with the help of the Aleksandrov's auto-regularization method of Gauss-Newton type for ill-posed problems. In the obtained generalized model the corrections to the binding energy depend on nine proton (2, 8, 14, 20, 28, 50, 82, 108, 124) and ten neutron (2, 8, 14, 20, 28, 50, 82, 124, 152, 202) magic numbers as well on the asymptotic boundaries of their influence. These results help us to evaluate the borders of the nuclear landscape and show their limit. The efficiency of the applied approach was checked by comparing relevant results with the results obtained independently.
Comments:
9 pages, 1 figure, Proceedings of the International Symposium on Exotic Nuclei EXON-2016, Kazan, Russia, 4-10 September 2016. based on arXiv:1602.06777
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1708.07966 [pdf]
Exotic Nuclei, p.330-337 (2017)·0 citations
02
[Submitted on 27 Aug 2017]
Scattering of decuplet baryons in chiral effective field theory
J. Haidenbauer🇩🇪 · S. Petschauer🇩🇪 · N. Kaiser🇩🇪 · Ulf-G. Meißner🇩🇪 · W. Weise🇩🇪
A formalism for treating the scattering of decuplet baryons in chiral effective field theory is developed. The minimal Lagrangian and potentials in leading-order SU(3) chiral effective field theory for the interactions of octet baryons ( $B$ ) and decuplet baryons ( $D$ ) for the transitions $B B \to B B$ , $B B \leftrightarrow D B$ , $D B \to D B$ , $B B \leftrightarrow D D$ , $D B \leftrightarrow D D$ , and $D D \to D D$ are provided. As an application of the formalism we compare with results from lattice QCD simulations for $ΩΩ$ and $N Ω$ scattering. Implications of our results pertinent to the quest for dibaryons are discussed.
Comments:
26 pages, 6 figures; minor corrections in the text, references added
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1708.08071 [pdf]
EPJC(2017)·42 citations
03
[Submitted on 27 Aug 2017]
From Strangeness Enhancement to Quark-Gluon Plasma Discovery
Peter Koch🇩🇪 · Berndt Müller🇺🇸 · Johann Rafelski (Arizona)🇺🇸
This is a short survey of signatures and characteristics of the quark-gluon plasma in the light of experimental results that have been obtained over the past three decades. In particular, we present an in-depth discussion of the strangeness observable, including a chronology of the experimental effort to detect QGP at CERN-SPS, BNL-RHIC, and CERN-LHC.
Comments:
30 pages, about 20 figures; Dedicated to our mentor Walter Greiner; to be published in the memorial volume edited by Peter O. Hess
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1708.08115 [pdf]
Int.J.Mod.Phys.A(2017)·61 citations
04
[Submitted on 27 Aug 2017]
Freezeout systematics due to the hadron spectrum
Sandeep Chatterjee🇵🇱 · Debadeepti Mishra🇮🇳 · Bedangadas Mohanty🇮🇳 · Subhasis Samanta🇮🇳
We investigate systematics of the freezeout surface in heavy ion collisions due to the hadron spectrum. The role of suspected resonance states that are yet to be confirmed experimentally in identifying the freezeout surface has been investigated. We have studied two different freezeout schemes - unified freezeout scheme where all hadrons are assumed to freezeout at the same thermal state and a flavor dependent sequential freezeout scheme with different freezeout thermal states for hadrons with or without valence strange quarks. The data of mean hadron yields as well as scaled variance of net proton and net charge distributions have been analysed. We find the freezeout temperature $T$ to drop by $\sim 5%$ while the dimensionless freezeout parameters $μ_{B} / T$ and $V T^{3}$ ( $μ_{B}$ and $V$ are the baryon chemical potential and the volume at freezeout respectively) are insensitive to the systematics of the input hadron spectrum. The observed hint of flavor hierarchy in $T$ and $V T^{3}$ with only confirmed resonances survives the systematics of the hadron spectrum. It is more prominent between $s_{N N} \sim 10 - 100$ GeV where the maximum hierarchy in $T \sim 10%$ and $V T^{3} \sim 40%$ . However, the uncertainties in the thermal parameters due to the systematics of the hadron spectrum and their decay properties do not allow us to make a quantitative estimate of the flavor hierarchy yet.
Comments:
version accepted for publication
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1708.08152 [pdf]
PRC(2017)·39 citations
05
[Submitted on 28 Aug 2017]
Alpha Clustering with a Hollow Structure --- Geometrical Structure of Alpha Clusters from Platonic Solids to Fullerene Shape
Akihiro Tohsaki · Naoyuki Itagaki
We study $α$ -cluster structure based on the geometric configurations with a microscopic framework, which takes full account of the Pauli principle, and which also employs an effective inter-nucleon force including finite-range three-body terms suitable for microscopic alpha-cluster models. Here, special attention is focused upon the $α$ clustering with a hollow structure; all the $α$ clusters are put on the surface of a sphere. All the Platonic solids (five regular polyhedra) and the fullerene-shaped polyhedron coming from icosahedral structure are considered. Furthermore, two configurations with dual polyhedra, hexahedron-octahedron and dodecahedron-icosahedron, are also scrutinized. As a consequence, we insist on the possible existence of stable $α$ -clustering with a hollow structure for all the configurations. Especially, two configurations, that is, dual polyhedra of dodecahedron-icosahedron and fullerene, have a prominent hollow structure compared with other six configurations.
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1708.08193 [pdf]
PRC(2018)·4 citations
06
[Submitted on 28 Aug 2017]
Contribution of Kaon component in viscosity and conductivity of hadronic medium
Mahfuzur Rahaman🇧🇷 · Snigdha Ghosh🇮🇳 · Sabyasachi Ghosh🇮🇳 · Sourav Sarkar🇮🇳 · Jan-e Alam🇮🇳
The two-point correlation functions of kaonic viscous stress tensors and electro-magnetic currents have been calculated respectively to estimate the contributions of the strange sector in the shear viscosity and electrical conductivity of hadronic medium. In the one-loop correlators, kaon propagators contain a non-zero thermal width that leads to non-divergent values of transport coefficients. With the help of effective Lagrangian densities of strange hadrons, we have calculated in-medium self-energy of kaon for different possible mesonic loops, whose imaginary part provide the estimation of kaon thermal width. It is observed that near the quark-hadron transition temperature, the contribution of kaons to shear viscosity is larger and increases faster with temperature than pionic contribution. In case of electrical conductivity the trend due kaon component appears to be opposite in nature with respect to pion component.
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1708.08300 [pdf]
PRC(2018)·5 citations
07
[Submitted on 28 Aug 2017] (cross-list from hep-ph)
Effect of two loop correction in the formation of QGP droplet
S. Somorendro Singh🇮🇳
The effect of two loop correction in the formation of quark-gluon plasma (QGP) droplet is studied with the introduction of the two loop correction factor in the mean field potential. Due to the correction factor it shows stability in the droplet formation of QGP indicating at different parametrization factors of the QGP fluid. The correction factor in the potential also shows gluon parameter factor shifts to a larger value from its earlier value of gluon factor of one loop correction in obtaining the stable droplets. The results show decreasing in the observable QGP droplets and droplet sizes are found to be $1.5 - 2.0$ fm radii with the two loop correction. It indicates that there is parameter like Reynold's number which can control the dynamics of QGP droplet formation and the stability of droplet in the case of droplet formation with the two loop correction factor.
Comments:
7 pages, 7 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1708.08216 [pdf]
0 citations
08
[Submitted on 28 Aug 2017] (cross-list from hep-ph)
Collectivity from interference
Boris Blok🇮🇱 · Christian D. Jäkel🇧🇷 · Mark Strikman🇺🇸 · Urs Achim Wiedemann🇨🇭
In hadronic collisions, interference between different production channels affects momentum distributions of multi-particle final states. As this QCD interference does not depend on the strong coupling constant, it is part of the no-interaction baseline that needs to be controlled prior to searching for other manifestations of collective dynamics. Here, we introduce a model that is based on the QCD theory of multi-parton interactions and that allows one to study interference effects in the production of $m$ particles in hadronic collisions with $N$ parton-parton interactions ("sources"). In an expansion in powers of $1/ (N_{c}^{2} - 1)$ and to leading order in the number of sources $N$ , we calculate interference effects in the $m$ -particle spectra and we determine from them the second and fourth order cumulant momentum anisotropies $v_{n}$ . Without invoking any azimuthal asymmetry and any density dependent non-linear dynamics in the incoming state, and without invoking any interaction in the final state, we find that QCD interference alone can give rise to values for $v_{n} {2}$ and $v_{n} {4}$ , $n$ even, that persist unattenuated for increasing number of sources, that may increase with increasing multiplicity and that agree with measurements in proton-proton (pp) collisions in terms of the order of magnitude of the signal and the approximate shape of the transverse momentum dependence. We further find that the non-abelian features of QCD interference can give rise to odd harmonic anisotropies. These findings indicate that the no-interaction baseline including QCD interference effects can make a sizeable if not dominant contribution to the measured $v_{n}$ coefficients in pp collisions. Prospects for analyzing QCD interference contributions further and their possible relevance for proton-nucleus and nucleus-nucleus collisions are discussed shortly.
Comments:
49 pages, 15 figures, revised version to appear in JHEP
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1708.08241 [pdf]
JHEP(2017)·56 citations
09
[Submitted on 28 Aug 2017] (cross-list from astro-ph.HE)
Tabulated Neutron Star Equations of State Modeled within the Chiral Mean Field Model
V. Dexheimer🇺🇸
In this special issue article, I review some of the accomplishments of the chiral mean field (CMF) model, which contains nucleon, hyperon, and quark degrees of freedom, and its applications to proto-neutron and neutron stars. I also present a set of equation of state and particle population tables built using the CMF model subject to physical constraints necessary to reproduce different environments, such as those present in cold neutron stars, core-collapse supernova explosions and different stages of compact star mergers.
Comments:
PASA special issue on the Neutron Stars, related to the Compstar conference in Warsaw
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Theory (nucl-th)
arXiv:
1708.08342 [pdf]
Publ.Astron.Soc.Austral.(2017)·26 citations
10
[Submitted on 28 Aug 2017] (cross-list from hep-ph)
Observables for possible QGP signatures in central pp collisions
Michelangelo L. Mangano🇨🇭 · Benjamin Nachman🇺🇸
Proton-proton (pp) data show collective effects, such as long-range azimuthal correlations and strangeness enhancement, which are similar to phenomenology observed in heavy ion collisions. Using simulations with and without explicit existing models of collective effects, we explore new ways to probe pp collisions at high multiplicity, in order to suggest measurements that could help identify the similarities and differences between large- and small-scale collective effects. In particular, we focus on the properties of jets produced in ultra-central pp collisions in association with a Z boson. We consider observables such as jet energy loss and jet shapes, which could point to the possible existence of an underlying quark-gluon plasma, or other new dynamical effects related to the presence of large hadronic densities.
Comments:
32 pages, 20 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1708.08369 [pdf]
EPJC(2018)·30 citations

Affiliations

first authorsco-authorsvia INSPIRE