Nuclear Theory·nucl-th

Tuesday·July 27, 2021

18 papers—8 primary·10 cross-listed

01
Nuclear Effective Field Theories: Reverberations of the early days
U. van Kolck🇫🇷
Effective field theories are recognized nowadays as the framework to describe low-energy nuclear structure and reactions consistently with the underlying theory of the strong interactions, QCD. It was not always so. As we celebrate the 30 years of the first publications, I collect here some memories from those early days. I also discuss some of the key issues that were raised back then and, despite all progress, are still with us. Dedicated to the memory of Steven Weinberg, whose ideas will not die, wherever they may lead.
nucl-thhep-phphysics.hist-phFew Body Syst.(2021)·16 citations
02
Analytic solutions of relativistic dissipative spin hydrodynamics with Bjorken expansion
Dong-Lin Wang🇨🇳 · Shuo Fang🇨🇳 · Shi Pu🇨🇳
We have studied analytically the longitudinally boost-invariant motion of a relativistic dissipative fluid with spin. We have derived the analytic solutions of spin density and spin chemical potential as a function of proper time $τ$ in the presence of viscous tensor and the second order relaxation time corrections for spin. Interestingly, analogous to the ordinary particle number density and chemical potential, we find that the spin density and spin chemical potential decay as $\sim τ^{- 1}$ and $\sim τ^{- 1/3}$ , respectively. It implies that the initial spin density may not survive at the freezeout hyper-surface. These solutions can serve both to gain insight on the dynamics of spin polarization in relativistic heavy-ion collisions and as testbeds for further numerical codes.
nucl-thhep-phPRD(2021)·71 citations
03
Probing criticality with deep learning in relativistic heavy-ion collisions
Yige Huang🇨🇳 · Long-Gang Pang🇨🇳 · Xiaofeng Luo🇨🇳 · Xin-Nian Wang🇨🇳
Systems with different interactions could develop the same critical behaviour due to the underlying symmetry and universality. Using this principle of universality, we can embed critical correlations modeled on the 3D Ising model into the simulated data of heavy-ion collisions, hiding weak signals of a few inter-particle correlations within a large particle cloud. Employing a point cloud network with dynamical edge convolution, we are able to identify events with critical fluctuations through supervised learning, and pick out a large fraction of signal particles used for decision-making in each single event.
nucl-thhep-exhep-phnucl-exPLB(2022)·20 citations
04
Probing the in-medium $P_{T}$ -broadening by $γ$ +HF angular de-correlations
Sa Wang🇨🇳 · Jin-Wen Kang🇨🇳 · Wei Dai🇨🇳 · Ben-Wei Zhang🇨🇳 · Enke Wang🇨🇳
Angular correlations between vector boson and heavy flavors~(HF) are potentially new effective tools to gain insight into the partonic interactions in the quark-gluon plasma (QGP). In this paper, we present the theoretical study of the azimuthal angular de-correlations of $γ +$ HF in nucleus-nucleus collisions as a new probe of the in-medium $P_{T}$ -broadening effect. The initial production of $γ +$ HF in p+p is generated by SHERPA which matches the next-to-leading hard processes with parton shower. The in-medium heavy quark evolution is implemented by a Monte Carlo Langevin simulation, which takes into account the collisional and radiative energy loss. We observe considerable suppression at $Δ ϕ_{γ D} \sim π$ and enhancement at $Δ ϕ_{γ D} < 2.8$ in $γ +$ D azimuthal angular distribution in $0 - 10%$ Pb+Pb collisions at $s_{N N} =$ 5.02 TeV compared to the p+p baseline, which indicates evident in-medium $P_{T}$ -broadening of charm quarks. We also find that the overall modification patterns of $γ +$ D angular distribution are sensitive to the selection cut of D meson $p_{T}$ . Furthermore, by constructing the 2D ( $x_{J}^{γ D}, Δ ϕ_{γ D}$ ) correlation diagram, it's possible to display the respective impacts of the two aspects of jet quenching, energy loss and $P_{T}$ -broadening, on the final-state $γ +$ D observable simultaneously. Additionally, we find weaker angular de-correlations of $γ +$ B compared to $γ +$ D which may be helpful to understand the mass hierarchy in heavy-ion collisions. Finally, the nuclear modification of $Δ ϕ_{γ D}$ distributions in central $0 - 10%$ Au+Au collisions at RHIC energy is provided for completeness.
nucl-thhep-phEur.Phys.J.A 58 (2022) 7, 135·14 citations
05
Spectroscopic factors in dripline nuclei
J. Wylie🇺🇸 · J. Okołowicz🇵🇱 · W. Nazarewicz🇺🇸 · M. Płoszajczak🇫🇷 · S.M. Wang🇺🇸 · X. Mao🇺🇸 · N. Michel🇨🇳
Single-nucleon knockout reaction studies of the proton-dripline nuclei $^{9}$ C and $^{13}$ O suggest an appreciable suppression of spectroscopic factors. In this work, we calculate the one-neutron and one-proton spectroscopic factors for the mirror pair $^{9}$ C- $^{9}$ Li and $^{13}$ O using two variants of the continuum shell model: the complex-energy Gamow Shell Model and the real-energy Shell Model Embedded in the Continuum. Our results indicate that the continuum effects strongly suppress the spectroscopic factors of well-bound orbits in the dripline systems, but have less impact on the spectroscopic factors of weakly-bound states.
nucl-thnucl-exPRC(2021)·25 citations
06
Coexistence of isospin I = 0 and I = 1 pairings in asymmetric nuclear matter
Yi-Jun Yan · Xin-Le Shang · Jian-Min Dong · Wei Zuo
The coexistence of neutron-neutron (n-n), proton-proton (p-p), and neutron-proton (n-p) pairings is investigated by adopting an effective density-dependent contact pairing potential. These three types of pairings can coexist only if the n-p pairing is stronger than the n-n and p-p pairings for isospin asymmetric nuclear matter. In addition, the existence of n-n and p-p pairs might enhance n-p pairings in asymmetric nuclear matter when the n-p pairing strength is significantly stronger than the n-n and p-p ones. Conversely, the n-p pairing is reduced by the n-n and p-p pairs when the n-p pairing interaction approaches n-n and p-p pairings.
nucl-thCPC(2021)·2 citations
07
Exact solution of the Brueckner-Bethe-Goldstone equation with three-body forces in nuclear matter
Xin-Le Shang🇨🇳 · Jian-Min Dong🇨🇳 · Wei Zuo🇨🇳 · Peng Yin🇨🇳 · U. Lombardo4🇮🇹
An exact treatment of the operators Q/e(\omega) and the total momentum is adopted to solve the nuclear matter Bruecker-Bethe-Goldstone equation with two- and three-body forces. The single-particle potential, equation of state and nucleon effective mass are calculated from the exact G-matrix. The results are compared with those obtained under the angle-average approximation and the angle-average approximation with total momentum approximation. It is found that the angle-average procedure, whereas preventing huge calculations of coupled channels, nevertheless provides a fairly accurate approximation. On the contrary, the total momentum approximation turns out to be quite inaccurate compared to its exact counterpart.
nucl-thPRC(2021)·16 citations
08
Trapped two-nucleon system in energy-dependent effective field theory
Chenbo Li🇨🇳 · Jiexin Yu🇨🇳 · Rui Peng🇨🇳 · Songlin Lyu🇨🇳 · Bingwei Long🇨🇳
We discuss how to connect the energy levels of two-particle systems trapped by a harmonic-oscillator force to scattering amplitudes, with nucleon-nucleon scattering phase shifts in uncoupled channels as the application. At the center of the proposed framework is the energy-dependent effective field theory that aims to expand observables in a neighborhood around each reference energy, often taken to be one of the energy levels. We also investigate how to disentangle the trapping force at short distances and the intrinsic interaction between the particles.
nucl-thhep-latPRC(2021)·4 citations

Affiliations

first authorsco-authorsvia INSPIRE