Nuclear Theory·nucl-th

Wednesday·April 19, 2017

15 papers—9 primary·6 cross-listed

01
[Submitted on 17 Apr 2017]
Jet modifications in event-by-event hydrodynamically evolving media
Jacquelyn Noronha-Hostler🇺🇸
The nearly perfect fluid-like nature of the Quark Gluon Plasma may be understood through two key experimental signatures: collective flow and jet suppression. Event-by-event relativistic viscous hydrodynamics (with an extremely small shear viscosity to entropy density ratio) has been very successful at describing collective flow observables for the last 7 years. More recently, the effects of event-by-event fluctuations have been studied in the context of high $p_{T}$ particles that lose energy as they pass through the dense Quark Gluon Plasma liquid. In this summary of the corresponding plenary talk at Quark Matter 2017, the recent developments on the effects of event-by-event fluctuations on jet suppression are summarized.
Comments:
8 pages, 7 figures, proceedings for Quark Matter 2017
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1704.05118 [pdf]
NPA(2017)·0 citations
02
[Submitted on 17 Apr 2017]
Pairing in the BCS and LN approximations using continuum single particle level density
R. M. Id Betan · C. E. Repetto
Understanding the properties of drip line nuclei requires to take into account the correlations with the continuum spectrum of energy of the system. This paper has the purpose to show that the continuum single particle level density is a convenient way to consider the pairing correlation in the continuum. Isospin mean-field and isospin pairing strength are used to find the Bardeen-Cooper-Schrieffer (BCS) and Lipkin-Nogami (LN) approximate solutions of the pairing Hamiltonian. Several physical properties of the whole chain of the Tin isotope, as gap parameter, Fermi level, binding energy, and one- and two-neutron separation energies, were calculated and compared with other methods and with experimental data when they exist. It is shown that the use of the continuum single particle level density is an economical way to include explicitly the correlations with the continuum spectrum of energy in large scale mass calculation. It is also shown that the computed properties are in good agreement with experimental data and with more sophisticated treatment of the pairing interaction.
Comments:
21 pages, 9 figures, 4 tables, 58 references
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1704.05149 [pdf]
NPA(2017)·4 citations
03
[Submitted on 18 Apr 2017]
Determination of the density region of the symmetry energy probed by the $π^{-} / π^{+}$ ratio
Gao-Chan Yong🇨🇳 · Yuan Gao🇨🇳 · Gao-Feng Wei🇨🇳 · Ya-Fei Guo🇨🇳 · Wei Zuo🇨🇳
The studies, from several independent methods, consistently show that $π^{-} / π^{+}$ ratio in the $^{132}$ Sn+ $^{124}$ Sn reaction at 300 MeV/nucleon, which is being carried out at Radioactive Isotope Beam Facility (RIBF) in Japan, just probes the symmetry energy around saturation density.
Comments:
6 pages, 6 figures, accepted by Journal of Physics G: Nuclear and Particle Physics
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1704.05166 [pdf]
J.Phys.G(2019)·13 citations
04
[Submitted on 18 Apr 2017]
Green's function relativistic mean field theory for $Λ$ hypernuclei
Su-Hong Ren🇨🇳 · Ting-Ting Sun🇨🇳 · Wei Zhang🇨🇳
The relativistic mean-field theory with Green's function method is extended to study $Λ$ hypernuclei. Taking hypernucleus $_{Λ}^{61}$ Ca as an example, the single-particle resonant states for $Λ$ hyperons are investigated by analyzing density of states and the corresponding energies and widths are given. Different behaviors are observed for the resonant states, i.e., the distributions of the very narrow $1 f_{5/2}$ and $1 f_{7/2}$ states are very similar as bound states while that of the wide $1 g_{7/2}$ and $1 g_{9/2}$ states are like scattering states. Besides, the impurity effect of $Λ$ hyperons on the single-neutron resonant states are investigated. For most of the resonant states, both the energies and widths decrease with adding more $Λ$ hyperons due to the attractive $Λ N$ interaction. Finally, the energy level structure of $Λ$ hyperons in the Ca hypernucleus isotopes with mass number $A = 53 - 73$ are studied, obvious shell structure and small spin-orbit splitting are found for the single- $Λ$ spectrum.
Comments:
10pages, 6 figures,2 tables
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1704.05192 [pdf]
PRC(2017)·36 citations
05
[Submitted on 18 Apr 2017]
$p Ξ^{-}$ Correlation in Relativistic Heavy Ion Collisions with Nucleon-Hyperon Interaction from Lattice QCD
Tetsuo Hatsuda🇯🇵 · Kenji Morita🇯🇵 · Akira Ohnishi🇯🇵 · Kenji Sasaki🇯🇵
On the basis of the $p Ξ^{-}$ interaction extracted from (2+1)-flavor lattice QCD simulations at the physical point, the momentum correlation of $p$ and $Ξ^{-}$ produced in relativistic heavy ion collisions is evaluated. $C_{SL} (Q)$ defined by a ratio of the momentum correlations between the systems with different source sizes is shown to be largely enhanced at low momentum due to the strong attraction between $p$ and $Ξ^{-}$ in the $I = J = 0$ channel. Thus, measuring this ratio at RHIC and LHC and its comparison to the theoretical analysis will give a useful constraint on the $p Ξ^{-}$ interaction.
Comments:
4 pages, 2 figures; proceedings contribution for Quark Matter 2017
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex)
arXiv:
1704.05225 [pdf]
NPA(2017)·53 citations
06
[Submitted on 18 Apr 2017]
Initial conditions for hydrodynamics from kinetic theory equilibration
Aleksi Kurkela🇨🇭 · Aleksas Mazeliauskas🇺🇸 · Jean-François Paquet🇺🇸 · Sören Schlichting🇺🇸 · Derek Teaney🇺🇸
We use effective kinetic theory to study the pre-equilibrium dynamics in heavy-ion collisions. We describe the evolution of linearized energy perturbations on top of out-of-equilibrium background to the energy-momentum tensor at a time when hydrodynamics becomes applicable. We apply this description to IP-Glasma initial conditions and find an overall smooth transition to hydrodynamics. In a phenomenologically favorable range of $η / s$ values, early time dynamics can be accurately described in terms of a few functions of a scaled time variable $τ T / (η / s)$ . Our framework can be readily applied to other initial state models to provide the pre-equilibrium dynamics of the energy momentum tensor.
Comments:
5 pages, 5 figures, Proceedings for the 26th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter 2017), February 5-11 2017, Chicago, Illinois, USA
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1704.05242 [pdf]
NPA(2017)·5 citations
07
[Submitted on 18 Apr 2017]
On the norm overlap between many-body states. I. Uncorrelated overlap between arbitrary Bogoliubov product states
B. Bally🇫🇷 · T. Duguet🇫🇷
State-of-the-art multi-reference energy density functional calculations require the computation of norm overlaps between different Bogoliubov quasiparticle many-body states. It is only recently that the efficient and unambiguous calculation of such norm kernels has become available under the form of Pfaffians~[L. M. Robledo, Phys. Rev. C79, 021302 (2009)]. The goals of this work is (i) to propose and implement an alternative to the Pfaffian method to compute unambiguously the norm overlap between arbitrary Bogoliubov quasiparticle states and (ii) to extend the first point to explicitly correlated norm kernels at play in recently developped particle-number-restored Bogoliubov coupled-cluster (PNR-BCC) and particle-number-restored many-body perturbation (PNR-BMBPT) ab initio theories~[T. Duguet and A. Signoracci, J. Phys. G44, 015103 (2017)]. Point (i) constitutes the purpose of the present paper while point (ii) is addressed in a forthcoming companion paper. We generalize the method used in~[T. Duguet and A. Signoracci, J. Phys. G44, 015103 (2017)] to obtain the norm overlap between arbitrary Bogoliubov product states under a closed-form expression. The formula is physically intuitive, accurate, versatile and relies on elementary linear algebra operations. It equally applies to norm overlaps between Bogoliubov states of even or odd number parity. Numerical applications illustrate these features and provide a transparent representation of the content of the norm overlaps. Furthermore, the closed-form expression extends naturally to correlated overlaps at play in PNR-BCC and PNR-BMBPT. As such, the straight overlap between Bogoliubov states is the zeroth-order reduction of more involved norm kernels to be studied in the forthcoming paper.
Comments:
25 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1704.05324 [pdf]
PRC(2018)·21 citations
08
[Submitted on 13 Apr 2017]
A Detailed Study and Synthesis of Flow Observables in the IP-Glasma+MUSIC+UrQMD Framework
Scott McDonald🇨🇦 · Chun Shen🇨🇦 · Francois Fillion-Gourdeau🇨🇦 · Sangyong Jeon🇨🇦 · Charles Gale🇨🇦
In this work we use the IP-Glasma+MUSIC+UrQMD framework to systematically study a wide range of hadronic flow observables at 2.76 TeV. In addition to the single particle spectra and anisotropic flow coefficients $v_{n}$ previously studied in \cite{1609.02958}, we consider event-plane correlations, non-linear response coefficients $χ_{n pq}$ , and event shape engineering. Taken together, these observables provide a wealth of insight into the collective behavior of the QGP and initial state fluctuations. They shed light on flow fluctuations, flow at fixed system size but different initial geometries, as well as the non-linear hydrodynamic response to the initial state spatial eccentricities. By synthesizing this information we can gain further insight into the transport properties of the QGP as well as the fluctuation spectrum of the initial state.
Comments:
To be submitted to the conference proceedings for the XXVIth International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter 2017), held Feb 5-11, 2017 in Chicago, Illinois, USA
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1704.05362 [pdf]
NPA(2017)·8 citations
09
[Submitted on 17 Apr 2017]
Chiral Vortical and Magnetic Effects in Anomalous Hydrodynamics
Xingyu Guo🇨🇳 · Dmitri E. Kharzeev🇺🇸 · Xu-Guang Huang🇨🇳 · Wei-Tian Deng🇨🇳 · Yuji Hirono🇺🇸
We employ a 3+1D anomalous hydrodynamics with initial condition generated by HIJING to simulate the chiral vortical effect and the chiral magnetic effect in heavy-ion collisions. This allows us to calculate the charge-dependent two-particle correlations with respect to the reaction plane at different collision energies and centralities. We then compare the computed results with the experimental data and give discussions on the possible background effects.
Comments:
4 pages, 2 figures, as a contribution to the proceedings for Quark Matter 2017
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1704.05375 [pdf]
NPA(2017)·10 citations

Affiliations

first authorsco-authorsvia INSPIRE