Nuclear Theory·nucl-th

Thursday·August 19, 2021

11 papers—4 primary·7 cross-listed

01
[Submitted on 18 Aug 2021]
Interplay between core and corona components in high-energy nuclear collisions
Yuuka Kanakubo🇯🇵 · Yasuki Tachibana🇯🇵 · Tetsufumi Hirano🇯🇵
We establish the updated version of dynamical core--corona initialization framework (DCCI2) as a unified description from small to large colliding systems and from low to high transverse momentum ( $p_{T}$ ) regions. Using DCCI2, we investigate effects of interplay between locally equilibrated and non-equilibrated systems, in other words, core and corona components in high-energy nuclear collisions. Given experimental multiplicity distributions and yield ratios of $Ω$ baryons to charged pions as inputs, we extract the fraction of core and corona components in p+p collisions at $s = 7$ TeV and Pb+Pb collisions at $s_{N N} = 2.76$ TeV. We find core contribution overtakes corona contribution as increasing multiplicity above $⟨ d N_{ch} / d η ⟩_{∣ η ∣ < 0.5} \sim 18$ regardless of the collision system or energy. We also see that the core contribution exceeds the corona contribution only in 0.0-0.95\% multiplicity class in p+p collisions. Notably, there is a small enhancement of corona contribution with $\sim 20$ \% below $p_{T} \sim 1$ GeV even in minimum bias Pb+Pb collisions. We find that the corona contribution at low $p_{T}$ gives $\sim 15$ - $38$ $%$ correction on $v_{2} {2}$ at $N_{ch} ≲ 370$ . This raises a problem in conventional hydrodynamic analyses in which low $p_{T}$ soft hadrons originate solely from core components. We finally scrutinize the roles of string fragmentation and the longitudinal expansion in the transverse energy per unit rapidity, which is crucial in initial conditions for hydrodynamics from event generators based on string models.
Comments:
25 pages, 9 figures (bug in viewing PDF file is fixed)
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2108.07943 [pdf]
PRC(2022)·45 citations
02
[Submitted on 18 Aug 2021]
Nucleon-nucleon correlations in the extreme oxygen isotopes
S. M. Wang · W. Nazarewicz · R. J. Charity · L. G. Sobotka
There has been an upsurge of interest in two-nucleon decays thanks to the studies of nucleon-nucleon correlations. In our previous work, based on a novel time-dependent three-body approach, we demonstrated that the energy and angular correlations of the emitted nucleons can shed light on the structure of nucleonic pairs formed inside the nucleus. In this work, we apply the new framework to study the decay dynamics and properties of some extreme proton-rich and neutron-rich oxygen isotopes, including two-proton ( $2 p$ ) decays of $^{11, 12}$ O and two-neutron ( $2 n$ ) decay of $^{26}$ O. Here we show that the low- $ℓ$ components of $^{11, 12}$ O wave functions, which are affected by continuum and configuration-interaction effects, strongly impact decay dynamics and asymptotic correlations. In the calculated wave functions of $^{11, 12}$ O, diproton and cigarlike structures merge together during the tunneling process and the resulting energy- and angular correlations are very consistent with the experimental data. The asymptotic correlations of the $2 n$ decay of $^{26}$ O dramatically change as the two-neutron decay energy approaches the zero-energy threshold. The small reported value of $Q_{2 n}$ suggests that the $2 n$ decay of this nucleus can be understood in terms of the universal phase-space limit.
Comments:
7 pages, 4 figures. arXiv admin note: text overlap with arXiv:2104.03195
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2108.08007 [pdf]
J.Phys.G(2022)·20 citations
03
[Submitted on 18 Aug 2021]
Bottomonium suppression and flow in heavy-ion collisions
Michael Strickland🇺🇸
The strong suppression of bottomonia production in ultra-relativistic heavy-ion collisions is a smoking gun for the creation of a deconfined quark-gluon plasma (QGP). In this proceedings contribution, I review recent work that aims to provide a more comprehensive and systematic understanding of bottomonium dynamics in the QGP through the use of pNRQCD and an open quantum systems approach. This approach allows one to evolve the heavy-quarkonium reduced density matrix, taking into account non-unitary effective Hamiltonian evolution of the wave-function and quantum jumps between different angular momentum and color states. In the case of a strong coupled QGP in which E << T,m_D << 1/a_0, the corresponding evolution equation is Markovian and can therefore be mapped to a Lindblad evolution equation. To solve the resulting Lindblad equation, we make use of a stochastic unraveling called the quantum trajectories algorithm and couple the non-abelian quantum evolution to a realistic 3+1D viscous hydrodynamical background. Using a large number of Monte-Carlo sampled bottomonium trajectories, we make predictions for bottomonium R_AA and elliptic flow as a function of centrality and transverse momentum and compare to data collected by the ALICE, ATLAS, and CMS collaborations.
Comments:
6 pages, 3 figures; Plenary contribution to Strangeness in Quark Matter 2021 (Virtual)
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2108.08160 [pdf]
EPJ Web Conf.(2022)·2 citations
04
[Submitted on 18 Aug 2021]
Toward emulating nuclear reactions using eigenvector continuation
C. Drischler🇺🇸 · M. Quinonez🇺🇸 · P. G. Giuliani🇺🇸 · A. E. Lovell🇺🇸 · F. M. Nunes🇺🇸
We construct an efficient emulator for two-body scattering observables using the general (complex) Kohn variational principle and trial wave functions derived from eigenvector continuation. The emulator simultaneously evaluates an array of Kohn variational principles associated with different boundary conditions, which allows for the detection and removal of spurious singularities known as Kohn anomalies. When applied to the $K$ -matrix only, our emulator resembles the one constructed by Furnstahl et al. [Phys. Lett. B 809, 135719] although with reduced numerical noise. After a few applications to real potentials, we emulate differential cross sections for $^{40}$ Ca $(n, n)$ scattering based on a realistic optical potential and quantify the model uncertainties using Bayesian methods. These calculations serve as a proof of principle for future studies aimed at improving optical models.
Comments:
12 pages, 4 figures, 1 table; minor improvements, close to published version
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2108.08269 [pdf]
PLB(2021)·69 citations
05
[Submitted on 17 Aug 2021] (cross-list from hep-ph)
Heavy flavor jet production and substructure in electron-nucleus collisions
Hai Tao Li🇺🇸 · Ze Long Liu🇺🇸 · Ivan Vitev🇺🇸
Deep inelastic scattering on nuclei at the Electron-Ion Collider will open new opportunities to investigate the structure of matter. Heavy flavor-tagged jets are complementary probes of the partonic composition and transport coefficients of large nuclei, but introduce a new mass scale that modifies the structure of parton showers and must be carefully accounted for in perturbative calculations. In the framework of soft-collinear effective theory with Glauber gluon interactions, we present the first calculation of inclusive charm-jet and bottom-jet cross sections in electron-nucleus collisions at next-to-leading order and compare them to the reference electron-proton case. We also show predictions for the heavy flavor-tagged jet momentum sharing distributions to further clarify the correlated in-medium modification of jet substructure.
Comments:
13 pages, 5 figures; v2: references added, typos corrected, to appear in Phys.Lett.B
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2108.07809 [pdf]
PLB(2022)·30 citations
06
[Submitted on 17 Aug 2021] (cross-list from quant-ph)
Nonuniqueness of scattering amplitudes at special points
Makoto Natsuume🇯🇵 · Takashi Okamura🇯🇵
We point out little discussed phenomenon in elementary quantum mechanics. In one-dimensional potential scattering problems, the scattering amplitudes are not uniquely determined at special points in parameter space. We examine a few explicit examples. We also discuss the relation with the pole-skipping phenomena recently found in holographic duality. In the holographic pole-skipping, the retarded Green's functions are not uniquely determined at imaginary Matsubara frequencies. It turns out that this universality comes from the fact that the corresponding potential scattering problem has the angular momentum potential.
Comments:
14 pages, ReVTeX4.2; v2: several clarifications, published version
Subjects:
Quantum Physics (quant-ph); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2108.07832 [pdf]
PRD(2021)·13 citations
07
[Submitted on 18 Aug 2021] (cross-list from astro-ph.HE)
Strangeness in astrophysics: Theoretical developments
Veronica Dexheimer🇺🇸 · Krishna Aryal🇺🇸
In this conference proceeding, we review important theoretical developments related to the production of strangeness in astrophysics. This includes its effects in supernova explosions, neutron stars, and compact-star mergers. We also discuss in detail how the presence of net strangeness affects the deconfinement to quark matter, expected to take place at large densities and/or temperatures. We conclude that a complete description of dense matter containing hyperons and strange quarks is fundamental for the understanding of modern high-energy astrophysics.
Comments:
Conference Proceeding for the 19th International Conference on Strangeness in Quark Matter (SQM 2021)
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2108.07923 [pdf]
EPJ Web Conf.(2022)·1 citation
08
[Submitted on 18 Aug 2021] (cross-list from hep-lat)
Symmetries of temporal correlators and the nature of hot QCD
L. Ya. Glozman🇦🇹 · Y. Aoki🇯🇵 · S. Hashimoto🇯🇵 · C. Rohrhofer🇯🇵
The temperature of the chiral restoration phase transition at 130 MeV as well as the temperature of the center symmetry ("deconfinement") phase transition in a pure glue theory at 300 MeV are two independent temperatures and their interplay determines a structure of different regimes of hot QCD. Given a chiral spin symmetry of the color charge and of the chromoelectric interaction we can conclude from observed symmetries of spatial and temporal correlators of N_F=2 QCD with domain wall Dirac operator at physical quark masses that above the chiral symmetry restoration crossover around T_pc but below rougly 3T_pc there should exist an intermediate regime (the stringy fluid) of hot QCD that is characterized by approximate chiral spin symmetry and where degrees of freedom are chirally symmetric quarks bound into color singlet objects by the chromoelectric field. Above this intermediate regime the color charge and the chromoelectric field are Debye screened and one observes a transition to QGP with magnetic confinement.
Comments:
8 pages, A written version of a talk at Lattice 2021 conference
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2108.08073 [pdf]
PoS(2022)·2 citations
09
[Submitted on 18 Aug 2021] (cross-list from hep-ph)
Critical point and Bose-Einstein condensation in pion matter
V. A. Kuznietsov🇺🇦 · O. S. Stashko🇺🇦 · O. V. Savchuk🇩🇪 · M. I. Gorenstein🇩🇪
The Bose-Einstein condensation and the liquid-gas first order phase transition are studied in the interacting pion matter. Two phenomenological models are used: the mean-field model and the hybrid model. Free model parameters are fixed by fitting the lattice QCD data on the pion Bose condensate density at zero temperature. In spite of some minor differences the two model demonstrate an identical qualitative and very close quantitative behavior for the thermodynamic functions and electric charge fluctuations. A peculiar property of the considered models is an intersection of the Bose-Einstein condensation line and the line of the first order phase transition at the critical end point.
Comments:
11 pages, 7 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2108.08140 [pdf]
PRC(2021)·8 citations
10
[Submitted on 18 Aug 2021] (cross-list from astro-ph.SR)
The structure and stability of massive hot white dwarfs
Sílvia P. Nunes · José D. V. Arbañil · Manuel Malheiro
We investigate the structure and stability against radial oscillations, pycnonuclear reactions, and inverse $β$ -decay of hot white dwarfs. We regard that the fluid matter is made up for nucleons and electrons confined in a Wigner-Seitz cell surrounded by free photons. It is considered that the temperature depends on the mass density considering the presence of an isothermal core. We find that the temperature produces remarkable effects on the equilibrium and radial stability of white dwarfs. The stable equilibrium configuration results are compared with white dwarfs estimated from the Extreme Ultraviolet Explorer Survey and Sloan Digital Sky Survey. We derive masses, radii, and central temperatures for the most massive white dwarfs according to surface gravity and effective temperature reported by the survey. We note that these massive stars are in the mass region where the general relativity effects are important. These stars are near the threshold of instabilities due to radial oscillations, pycnonuclear reaction, and inverse $β$ -decay. Regarding the radial stability of these stars as a function of the temperature, we obtain that the radial stability decreases with the increment of central temperature. We also obtain that the maximum mass point and the zero eigenfrequencies of the fundamental mode are determined at the same central energy density. Regarding low-temperature stars, the pycnonuclear reactions occur in almost similar central energy densities, and the central energy density threshold for inverse $β$ -decay is not modified. For $T_{c} \geq 1.0 \times 1 0^{8} [K]$ , the onset of the radial instability is attained before the pycnonuclear reaction and the inverse $β$ -decay.
Comments:
To appear in the Astrophysical Journal
Subjects:
Solar and Stellar Astrophysics (astro-ph.SR); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
2108.08238 [pdf]
ApJ(2021)·20 citations
11
[Submitted on 18 Aug 2021] (cross-list from hep-ph)
Mining for Gluon Saturation at Colliders
Astrid Morreale🇺🇸 · Farid Salazar🇺🇸
Quantum chromodynamics (QCD) is the theory of strong interactions of quarks and gluons collectively called partons, the basic constituents of all nuclear matter. Its non-abelian character manifests in nature in the form of two remarkable properties: color confinement and asymptotic freedom. At high energies, perturbation theory can result in the growth and dominance of very gluon densities at small-x. If left uncontrolled, this growth can result in gluons eternally growing violating a number of mathematical bounds. The resolution to this problem lies by balancing gluon emissions by recombinating gluons at high energies : phenomena of gluon saturation. High energy nuclear and particle physics experiments have spent the past decades quantifying the structure of protons and nuclei in terms of their fundamental constituents confirming predicted extraordinary behavior of matter at extreme density and pressure conditions. In the process they have also measured seemingly unexpected phenomena. We will give a state of the art review of the underlying theoretical and experimental tools and measurements pertinent to gluon saturation physics. We will argue for the need of high energy electron-proton/ion colliders such as the proposed EIC (USA) and LHeC (Europe) to consolidate our knowledge of QCD in the small x kinematic domains.
Comments:
49 pages, 32 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2108.08254 [pdf]
Universe(2021)·168 citations

Affiliations

first authorsco-authorsvia INSPIRE