Nuclear Theory·nucl-th

Friday·April 14, 2017

13 papers—9 primary·4 cross-listed

01
Phase transitions in dense matter
Veronica Dexheimer🇺🇸 · Matthias Hempel🇨🇭 · Igor Iosilevskiy🇷🇺 · Stefan Schramm🇩🇪
As the density of matter increases, atomic nuclei disintegrate into nucleons and, eventually, the nucleons themselves disintegrate into quarks. The phase transitions (PT's) between these phases can vary from steep first order to smooth crossovers, depending on certain conditions. First-order PT's with more than one globally conserved charge, so-called non-congruent PT's, have characteristic differences compared to congruent PT's. In this conference proceeding we discuss the non-congruence of the quark deconfinement PT at high densities and/or temperatures relevant for heavy-ion collisions, neutron stars, proto-neutron stars, supernova explosions, and compact-star mergers.
nucl-thastro-ph.HEastro-ph.SRNPA(2017)·8 citations
02
On mass polarization effect in three-body systems
I. Filikhin · R. Ya. Kezerashvili · V. M. Suslov · B. Vlahovic
We evaluate the mass polarization term of the kinetic-energy operator for different three-body nuclear $AA B$ systems by employing the method of Faddeev equations in configuration space. For a three-boson system this term is determined by the difference of the doubled binding energy of the $A B$ subsystem $2 E_{2}$ and the three-body binding energy $E_{3} (V_{AA} = 0)$ when the interaction between the identical particles is omitted. In this case: $∣ E_{3} (V_{AA} = 0) ∣ > 2 ∣ E_{2} ∣$ . In the case of a system complicated by isospins(spins), such as the kaonic clusters $K^{-} K^{-} p$ and $pp K^{-}$ , the similar evaluation impossible. For these systems it is found that $∣ E_{3} (V_{AA} = 0) ∣ < 2 ∣ E_{2} ∣$ . A model with an $A B$ potential averaged over spin(isospin) variables transforms the later case to the first one. The mass polarization effect calculated within this model is essential for the kaonic clusters. Besides we have obtained the relation $∣ E_{3} ∣ \leq ∣2 E_{2} ∣$ for the binding energy of the kaonic clusters.
nucl-thFew Body Syst.(2018)·12 citations
03
Origins of collectivity in small systems
Bjoern Schenke🇺🇸
We review recent developments in the theoretical description and understanding of multi-particle correlation measurements in collisions of small projectiles (p/d/ $^{3}$ He) with heavy nuclei (Au, Pb) as well as proton+proton collisions. We focus on whether the physical processes responsible for the observed long range rapidity correlations and their azimuthal structure are the same in small systems as in heavy ion collisions. In the latter they are interpreted as generated by the initial spatial geometry being transformed into momentum correlations by strong final state interactions. However, explicit calculations show that also initial state momentum correlations are present and could contribute to observables in small systems. If strong final state interactions are present in small systems, recent developments show that results are sensitive to the shape of the proton and its fluctuations.
nucl-thNPA(2017)·32 citations
04
Axially deformed solution of the Skyrme-Hartree-Fock-Bogolyubov equations using the transformed harmonic oscillator basis (III) hfbtho (v3.00): a new version of the program
R. Navarro Perez🇺🇸 · N. Schunck🇺🇸 · R.-D. Lasseri🇫🇷 · C. Zhang🇺🇸 · J. Sarich🇺🇸
We describe the new version 3.00 of the code HFBTHO that solves the nuclear Hartree-Fock (HF) or Hartree-Fock-Bogolyubov (HFB) problem by using the cylindrical transformed deformed harmonic oscillator basis. In the new version, we have implemented the following features: (i) the full Gogny force in both particle-hole and particle-particle channels, (ii) the calculation of the nuclear collective inertia at the perturbative cranking approximation, (iii) the calculation of fission fragment charge, mass and deformations based on the determination of the neck (iv) the regularization of zero-range pairing forces (v) the calculation of localization functions (vi)MPI interface for large-scale mass table calculations.
nucl-thComput.Phys.Commun.(2017)·77 citations
05
Global and local spin polarization in heavy ion collisions: a brief overview
Qun Wang🇨🇳
We give a brief overview about recent developments in theories and experiments on the global and local spin polarization in heavy ion collisions.
nucl-thNPA(2017)·78 citations
06
How brightly does the Glasma shine? Photon production off-equilibrium
Jürgen Berges🇩🇪 · Klaus Reygers🇩🇪 · Naoto Tanji🇩🇪 · Raju Venugopalan🇺🇸
We present a parametric estimate of photon production at early times in heavy-ion collisions based on a consistent weak coupling thermalization scenario. We quantify the contribution of the off-equilibrium Glasma phase relative to that of a thermalized Quark-Gluon Plasma. Taking into account the constraints from charged hadron multiplicity data, the Glasma contribution is found to be significant especially for large values of the saturation scale.
nucl-thhep-phNPA(2017)·7 citations
07
Majorana flipping of quarkonium spin states in transient magnetic field
Nirupam Dutta🇮🇳 · Surasree Mazumder🇮🇳
We demonstrate that spin flipping transitions occur between various quarkonium spin states due to transient magnetic field produced in non central heavy ion collisions (HICs). The inhomogeneous nature of the magnetic field results in \textit{non adiabatic evolution} of (spin)states of quarkonia moving inside the transient magnetic environment. Our calculations explicitly show that the consideration of azimuthal inhomogeneity gives rise to dynamical mixing between different spin states owing to Majorana spin flipping. Notably, this effect of non-adiabaticity is novel and distinct from previously predicted mixing of the singlet and one of the triplet states of quarkonia in the presence of a static and homogeneous magnetic field.
nucl-thhep-phEPJC(2018)·13 citations
08
A hybrid approach to relativistic heavy-ion collisions at the RHIC BES energies
Chun Shen🇺🇸 · Gabriel Denicol🇧🇷 · Charles Gale🇨🇦 · Sangyong Jeon🇨🇦 · Akihiko Monnai🇫🇷 · Bjoern Schenke🇺🇸
Using a hybrid (viscous hydrodynamics + hadronic cascade) framework, we model the bulk dynamical evolution of relativistic heavy-ion collisions at Relativistic Heavy Ion Collider (RHIC) Beam Energy Scan (BES) collision energies, including the effects from non-zero net baryon current and its dissipative diffusion. This framework is in full (3+1)D, which allows us to study the non-trivial longitudinal structure and dynamics of the collision systems, for example baryon stopping and transport, as well as longitudinal fluctuations. For the first time, the quantitative effect of net-baryon diffusion on hadronic observables is addressed. Finally, we propose a dynamical initialization scheme to study the importance of the pre-equilibrium stage at the RHIC BES energies.
nucl-thhep-phnucl-exNPA(2017)·46 citations
09
Effects of bulk viscosity and hadronic rescattering in heavy ion collisions at RHIC and LHC
Sangwook Ryu🇨🇦 · Jean-François Paquet🇨🇦 · Chun Shen🇨🇦 · Gabriel Denicol🇧🇷 · Björn Schenke🇺🇸 · Sangyong Jeon🇨🇦 · Charles Gale🇨🇦
We describe ultra-relativistic heavy ion collisions at RHIC and the LHC with a hybrid model using the IP-Glasma model for the earliest stage and viscous hydrodynamics and microscopic transport for the later stages of the collision. We demonstrate that within this framework the bulk viscosity of the plasma plays an important role in describing the experimentally observed radial flow and azimuthal anisotropy simultaneously. We further investigate the dependence of observables on the temperature below which we employ the microscopic transport description.
nucl-thPRC(2018)·140 citations
10
Quenching of vector boson-tagged jets at the LHC
Hongxi Xing🇺🇸
Electroweak boson-tagged jet measurements provide a promising experimental channel to accurately study the physics of jet production and propagation in dense QCD medium. In this talk, we present theoretical predictions for the nuclear-induced attenuation of the differential cross section for isolated photon-tagged and $Z^{0}$ -tagged jet production in heavy ion collisions, and provide theoretical interpretations to the recent LHC data. We demonstrate quantitatively the significance of collisional and radiative energy losses, as revealed in the strong momentum asymmetry $d σ / d x_{V J}$ and nuclear modification $I_{AA}$ in central lead-lead reactions.
↳ hep-phnucl-thNPA(2017)·0 citations
11
Status of nuclear PDFs after the first LHC p-Pb run
Hannu Paukkunen🇫🇮
In this talk, I overview the recent progress on the global analysis of nuclear parton distribution functions (nuclear PDFs). After first introducing the contemporary fits, the analysis procedures are quickly recalled and the ambiguities in the use of experimental data outlined. Various nuclear-PDF parametrizations are compared and the main differences explained. The effects of nuclear PDFs in the LHC p-Pb hard-process observables are discussed and some future prospects sketched.
↳ hep-phhep-exnucl-thNPA(2017)·18 citations
12
Latest results from the EbyE NLO EKRT model
Kari J. Eskola🇫🇮 · Harri Niemi🇩🇪 · Risto Paatelainen🇫🇮 · Kimmo Tuominen🇫🇮
We review the results from the event-by-event next-to-leading order perturbative QCD + saturation + viscous hydrodynamics (EbyE NLO EKRT) model. With a simultaneous analysis of LHC and RHIC bulk observables we systematically constrain the QCD matter shear viscosity-to-entropy ratio eta/s(T), and test the initial state computation. In particular, we study the centrality dependences of hadronic multiplicities, pT spectra, flow coefficients, relative elliptic flow fluctuations, and various flow-correlations in 2.76 and 5.02 TeV Pb+Pb collisions at the LHC and 200 GeV Au+Au collisions at RHIC. Overall, our results match remarkably well with the LHC and RHIC measurements, and predictions for the 5.02 TeV LHC run are in an excellent agreement with the data. We probe the applicability of hydrodynamics via the average Knudsen numbers in the space-time evolution of the system and viscous corrections on the freeze-out surface.
↳ hep-phnucl-thNPA(2017)·13 citations
13
Bound state equation for the Nakanishi weight function
J. Carbonell🇫🇷 · T. Frederico🇧🇷 · V.A. Karmanov🇷🇺
The bound state Bethe-Salpeter amplitude was expressed by Nakanishi using a two-dimensional integral representation, in terms of a smooth weight function $g$ , which carries the detailed dynamical information. A similar, but one-dimensional, integral representation can be obtained for the Light-Front wave function in terms of the same weight function $g$ . By using the generalized Stieltjes transform, we first obtain $g$ in terms of the Light-Front wave function in the complex plane of its arguments. Next, a new integral equation for the Nakanishi weight function $g$ is derived for a bound state case. It has the standard form $g = N g$ , where $N$ is a two-dimensional integral operator. We give the prescription for obtaining the kernel $N$ starting with the kernel $K$ of the Bethe-Salpeter equation. The derivation is valid for any kernel given by an irreducible Feynman amplitude.
↳ hep-phhep-thnucl-thPLB(2017)·23 citations

Affiliations

first authorsco-authorsvia INSPIRE