Nuclear Theory·nucl-th

Wednesday·April 13, 2022

10 papers—1 primary·9 cross-listed

01
[Submitted on 12 Apr 2022]
Medium dependent relativistic NN potential: Application to the fusion dynamics
Mrutunjaya Bhuyan · Shilpa Rana · Nishu Jain · Raj Kumar · Suresh Kumar Patra · B. V. Carlson
In-medium effects are introduced in the microscopic description of the effective nucleon-nucleon (NN) interaction potential entitled DDR3Y in terms of the density-dependent nucleon-meson couplings within the Relativistic-Hartree-Bogoliubov (RHB) approach. The nuclear densities of the interacting target and projectile nuclei and NN potentials are obtained for non-linear NL3 $^{*}$ and TM1 parameter sets within the relativistic mean-field approach and density-dependent DDME1 and DDME2 parameter sets within the Relativistic-Hartree-Bogoliubov (RHB) formalism. The DDR3Y NN potential and the densities are used to obtain the nuclear potential by adopting the double folding approach. This nuclear potential is further used to probe the fusion dynamics within the $ℓ -$ summed Wong model for a few {\it even-even} systems leading to the formation of light, heavy and superheavy nuclei. The calculations are also performed for the relativistic R3Y, density-dependent and independent M3Y interaction potentials for the comparison. We observed that the DDR3Y NN potential gives a better overlap with the experimental data as compared to non-relativistic M3Y and DDM3Y NN potentials. From the comparison of R3Y and DDR3Y interactions, it is manifested that the inclusion of in-medium effects in terms of density-dependent nucleon-meson couplings raises the fusion barrier and consequently decreases the fusion and/or capture cross-section. Moreover, the nuclear densities, as well as the relativistic R3Y NN potential obtained for the NL3 $^{*}$ parameter set, are observed to give a comparatively better fit to the experimental data.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2204.05993 [pdf]
PRC(2022)·15 citations
02
[Submitted on 1 Apr 2022] (cross-list from hep-ph)
Freezing Out Fluctuations in Hydro+ Near the QCD Critical Point
Maneesha Pradeep🇺🇸 · Krishna Rajagopal🇺🇸 · Mikhail Stephanov🇺🇸 · Yi Yin🇨🇳
We introduce a freeze-out procedure to convert the critical fluctuations in a droplet of quark-gluon plasma (QGP) that has, as it expanded and cooled, passed close to a posited critical point on the phase diagram into cumulants of hadron multiplicities that can subsequently be measured. The procedure connects the out-of-equilibrium critical fluctuations described in concert with the hydrodynamic evolution of the droplet of QGP by extended hydrodynamics, known as Hydro+, with the subsequent kinetic description in terms of observable hadrons. We introduce a critical scalar isoscalar field sigma whose fluctuations cause correlations between observed hadrons due to the couplings of the sigma field to the hadrons via their masses. We match the QGP fluctuations obtained by solving the Hydro+ equations describing the evolution of critical fluctuations before freeze-out to the correlations of the sigma field. In turn, these are imprinted onto correlations and fluctuations in the multiplicity of hadrons, most importantly protons, after freeze-out via the generalization of the familiar half-century-old Cooper-Frye freeze-out prescription which we introduce. The proposed framework allows us to study the effects of critical slowing down and the consequent deviation of the observable predictions from equilibrium expectations quantitatively. We also quantify the suppression of cumulants due to conservation of baryon number. We demonstrate the procedure in practice by freezing out a Hydro+ simulation in an azimuthally symmetric and boost invariant background that includes radial flow discussed in arXiv:1908.08539.
Comments:
67 pages, 21 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2204.00639 [pdf]
PRD(2022)·55 citations
03
[Submitted on 11 Apr 2022] (cross-list from hep-ph)
Asymmetric transverse momentum broadening in an inhomogeneous medium
Yu Fu🇨🇳 · Jorge Casalderrey-Solana🇪🇸 · Xin-Nian Wang🇨🇳
Gradient jet tomography in high-energy heavy-ion collisions utilizes the asymmetric transverse momentum broadening of a propagating parton in an inhomogeneous medium. Such broadening is studied within a path integral description of the evolution of the Wigner distribution for a propagating parton in medium. Going beyond the eikonal approximation of multiple scattering, the evolution operator in the transverse direction can be expressed as the functional integration over all classical trajectories of a massive particle with the light-cone momentum $ω$ as its mass. With a dipole approximation of the Wilson line correlation function, evolution with the light-cone time $t$ is determined by the jet transport coefficient $q^$ that can vary with space and time. In a uniform medium with a constant $q^_{0}$ , the analytical solution to the Wigner distribution becomes a typical drifted Gaussian in both transverse momentum and coordinate with the diffusion width $q^_{0} t$ and $q^_{0} t^{3} /3 ω^{2}$ , respectively. In the case of a simple Gaussian-like transverse inhomogeneity with a spatial width $σ$ on top of a uniform medium, the final asymmetrical momentum distribution can be calculated semi-analytically. The transverse asymmetry defined for jet gradient tomography that characterizes the asymmetrical distribution is found to linearly correlate with the initial transverse position of the propagating parton within the domain of the inhomogeneity. It decreases with the parton energy $ω$ , increases with the propagation time initially and saturates when the diffusion distance is much larger than the size of the inhomogeneity or $t^{3} ≫ 3 ω^{2} σ^{2} / q^_{0}$ . The transverse momentum broadening due to the inhomogeneity also saturates at late time in contrast to the continued increase with time if the drifted diffusion in space is ignored.
Comments:
16 pages in ReVTeX with 5 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2204.05323 [pdf]
PRD(2023)·32 citations
04
[Submitted on 11 Apr 2022] (cross-list from hep-ph)
Hadron and light nucleus radii from electron scattering
Zhu-Fang Cui🇨🇳 · Daniele Binosi🇮🇹 · Craig D. Roberts🇨🇳 · Sebastian M. Schmidt🇩🇪
Conceptually, radii are amongst the simplest Poincaré-invariant properties that can be associated with hadrons and light nuclei. Accurate values of these quantities are necessary so that one may judge the character of putative solutions to the strong interaction problem within the Standard Model. However, limiting their ability to serve in this role, recent measurements and new analyses of older data have revealed uncertainties and imprecisions in the radii of the proton, pion, kaon, and deuteron. In the context of radius measurement using electron + hadron elastic scattering, the past decade has shown that reliable extraction requires complete elimination of bias associated with practitioner-dependent choices of data fitting functions. Different answers to that challenge have been offered; and this perspective describes the statistical Schlessinger point method (SPM), in unifying applications to proton, pion, kaon, and deuteron radii. Grounded in analytic function theory, independent of assumptions about underlying dynamics, free from practitioner-induced bias, and applicable in the same form to diverse systems and observables, the SPM returns an objective expression of the information contained in any data under consideration. Its robust nature and versatility make it suitable for use in many branches of experiment and theory.
Comments:
16 pages, 11 figures, 1 table. Review article commissioned by and accepted for publication in Chinese Physics C
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2204.05418 [pdf]
CPC(2022)·35 citations
05
[Submitted on 11 Apr 2022] (cross-list from nucl-ex)
Constraining the $^{30}$ P( $p, γ)^{31}$ S reaction rate in ONe novae via the weak, low-energy, $β$ -delayed proton decay of $^{31}$ Cl
T. Budner (1 and 2)🇺🇸 · M. Friedman (1 and 3)🇺🇸 · C. Wrede (1 and 2)🇺🇸 · B. A. Brown (1 and 2)🇺🇸 · J. José (4 and 5)🇪🇸 · D. Pérez-Loureiro (1)🇺🇸 · L. J. Sun (1 and 6)🇺🇸 · J. Surbrook (1 and 2)🇺🇸 · Y. Ayyad (1 and 7)🇺🇸 · D. W. Bardayan (8)🇺🇸 · K. Chae (9)🇰🇷 · A. A. Chen (10)🇨🇦 and 11 other authors
The $^{30}$ P $(p, γ)^{31}$ S reaction plays an important role in understanding nucleosynthesis of $A \geq 30$ nuclides in oxygen-neon novae. The Gaseous Detector with Germanium Tagging was used to measure $^{31}$ Cl $β$ -delayed proton decay through the key $J^{π} = 3/ 2^{+}$ , 260-keV resonance. The intensity $I_{β p}^{260} = 8. 3_{- 0.9}^{+ 1.2} \times 1 0^{- 6}$ represents the weakest $β$ -delayed, charged-particle emission ever measured below 400 keV, resulting in a proton branching ratio of $Γ_{p} /Γ = 2. 5_{- 0.3}^{+ 0.4} \times 1 0^{- 4}$ . By combining this measurement with shell-model calculations for $Γ_{γ}$ and past work on other resonances, the total $^{30}$ P $(p, γ)^{31}$ S rate has been determined with reduced uncertainty. The new rate has been used in hydrodynamic simulations to model the composition of nova ejecta, leading to a concrete prediction of $^{30}$ Si/ $^{28}$ Si excesses in presolar nova grains and the calibration of nuclear thermometers.
Comments:
7 pages, 2 figures, accepted to Physical Review Letters on April 4, 2022
Subjects:
Nuclear Experiment (nucl-ex); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Theory (nucl-th)
arXiv:
2204.05444 [pdf]
PRL(2022)·14 citations
06
[Submitted on 12 Apr 2022] (cross-list from hep-lat)
Centre Vortices in the Presence of Dynamical Fermions
James Biddle🇦🇺 · Waseem Kamleh🇦🇺 · Derek Leinweber🇦🇺
The behaviour of centre vortices in the presence of dynamical fermions is studied for the first time in the context of the static quark potential and the Landau-gauge gluon propagator. These results indicate that in the presence of dynamical fermions, centre vortices are able to better encapsulate the long-range behaviour of QCD, compared to previous studies on pure Yang-Mills lattices. This work provides strong evidence that centre vortices are responsible for the long-range linear potential and the enhanced infrared gluon propagator, which are indicative of confinement in QCD.
Comments:
8 pages, 4 figures. Proceedings of the 38th International Symposium on Lattice Field Theory (Lattice 2021), 26th - 30th July 2021, Zoom/Gather@Massachusetts Institute of Technology
Subjects:
High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2204.05468 [pdf]
PoS(2022)·0 citations
07
[Submitted on 12 Apr 2022] (cross-list from hep-ph)
Inverse scattering problem with a bare state
Yan Li🇨🇳 · Jia-Jun Wu🇨🇳
In hadron physics, molecular-like multihadron states can interact with compact multiquark states. The latter are modeled as bare states in the Hilbert space of a potential model. In this work, we study several potential models relevant to the bare state, and solve their inverse scattering problems. The first model, called "cc", is a separable potential model. We show that it can approximate (single-channel short-range) $S$ -wave near-threshold physics with an error of $O (β^{3} / M_{V}^{3})$ , where $β$ sets the maximum momentum of the near-threshold region and $M_{V}$ is the typical scale of the potential. The second model, called "bc", serves as the bare-state-dominance approximation, where interaction between continuum states is ignored. Under this model, even though the bare state is always crucial for a bound state's generation, a shallow bound state naturally tends to have a small bare-state proportion. Therefore, we need other quantities to quantify the importance of the bare state. The last model, called "bcc", is a combination of the first two models. This model not only serves as a correction to the bare-state-dominance approximation, but can also be used to understand the interplay between quark and hadron degrees of freedom. This model naturally leads to the presence of a Castillejo-Dalitz-Dyson (CDD) zero. We consider the energy decomposition of a bound state. The potential ratio of the bare-continuum interaction to the continuum self-interaction is proposed to understand how the bound state is generated. Model independently, an inequality for the potential ratio is derived. Based on the model "bcc", the CDD zero can be used to estimate the potential ratio. Finally, we apply these studies to the deuteron, $ρ$ meson, and $D_{s 0}^{*} (2317)$ , and analyze their properties.
Comments:
28 pages 2 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2204.05510 [pdf]
PRD(2022)·9 citations
08
[Submitted on 12 Apr 2022] (cross-list from astro-ph.HE)
Dark matter admixed neutron star properties in the light of X-ray pulse profile observations
Zhiqiang Miao🇨🇳 · Yaofeng Zhu🇨🇳 · Ang Li🇨🇳 · Feng Huang🇨🇳
The distribution of the dark matter (DM) in DM-admixed-neutron stars (DANSs) is supposed to be either a dense dark core or an extended dark halo, which is subject to the DM fraction of DANS ( $f_{χ}$ ) and the DM properties, such as the mass ( $m_{χ}$ ) and the strength of the self-interaction ( $y$ ). In this paper, we perform an in-depth analysis of the formation criterion for dark core/dark halo and point out that the relative distribution of these two components is essentially determined by the ratio of the central enthalpy of the DM component to that of the baryonic matter component inside DANSs. For the critical case where the radii of DM and baryonic matter are the same, we further derive an analytical formula to describe the dependence of $f_{χ}^{crit}$ on $m_{χ}$ and $y$ for given DANS mass. The relative distribution of the two components in DANSs can lead to different observational effects. We here focus on the modification of the pulsar pulse profile due to the extra light-bending effect in the case of a dark-halo existence and conduct the first investigation of the dark-halo effects on the pulse profile. We find that the peak flux deviation is strongly dependent on the ratio of the halo mass to the radius of the DM component. Lastly, we perform Bayesian parameter estimation on the DM particle properties based on the recent X-ray observations of PSR J0030+0451 and PSR J0740+6620 by the Neutron Star Interior Composition Explorer.
Comments:
13 pages, 10 figures, 1 table, ApJ (2022) accepted
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2204.05560 [pdf]
ApJ(2022)·82 citations
09
[Submitted on 12 Apr 2022] (cross-list from nucl-ex)
Chiral symmetry restoration at high matter density observed in pionic atoms
Takahiro Nishi🇯🇵 · Kenta Itahashi🇯🇵 · DeukSoon Ahn🇯🇵 · Georg P.A. Berg🇺🇸 · Masanori Dozono🇯🇵 · Daijiro Etoh🇯🇵 · Hiroyuki Fujioka🇯🇵 · Naoki Fukuda🇯🇵 · Nobuhisa Fukunishi🇯🇵 · Hans Geissel🇩🇪 · Emma Haettner🇩🇪 · Tadashi Hashimoto🇯🇵 and 36 other authors
Modern theories of physics tell that the vacuum is not an empty space. Hidden in the vacuum is a structure of anti-quarks $q ˉ$ and quarks $q$ . The $q ˉ$ and $q$ pair has the same quantum number as the vacuum and condensates in it since the strong interaction of the quantum chromodynamics (QCD) is too strong to leave it empty. The $q ˉ q$ condensation breaks the chiral symmetry of the vacuum. The expectation value $< q ˉ q >$ is an order parameter. For higher temperature or higher matter-density, $∣ < q ˉ q > ∣$ decreases reflecting the restoration of the symmetry. In contrast to these clear-cut arguments, experimental evidence is so far limited. First of all, the $q ˉ q$ is nothing but the vacuum itself. It is neither visible nor perceptible. In this article, we unravel this invisible existence by high precision measurement of pionic atoms, $π^{-}$ -meson-nucleus bound systems. Using the $π^{-}$ as a probe, we demonstrate that $∣ < q ˉ q > ∣$ is reduced in the nucleus at 58% of the normal nuclear density by a factor of 77 $\pm$ 2% compared with that in the vacuum. This reduction indicates that the chiral symmetry is partially restored due to the extremely high density of the nucleus. The present experimental result clearly exhibits the existence of the hidden structure, the chiral condensate, in the vacuum.
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2204.05568 [pdf]
Nat.Phys.(2023)·41 citations
10
[Submitted on 12 Apr 2022] (cross-list from nucl-ex)
A Study of Complete and Incomplete Reactions of $^{12}$ C + $^{169}$ Tm System at Energy Range $\approx$ 4.16-7.5 Mev/Nucleon
Getahun Kebede
In this paper an attempt was to measure, the excitation functions of $^{169}$ Tm( $^{12}$ C, 4n) $^{177}$ Re, $^{169}$ Tm( $^{12}$ C, 5n) $^{176}$ Re, $^{169}$ Tm( $^{12}$ C, $α$ n) $^{176}$ Ta, $^{169}$ Tm( $^{12}$ C, $α$ 2n) $^{175}$ Ta , $^{169}$ Tm( $^{12}$ C, $α$ 3n) $^{174}$ Ta , $^{169}$ Tm( $^{12}$ C, $α$ 4n) $^{173}$ Ta, and $^{169}$ Tm( $^{12}$ C, 2 $α$ 2n) $^{171}$ Lu reaction channels populated in the interaction of $^{12}$ C projectile with $^{169}$ Tm target were considered in order to investigate the mechanisms of complete and incomplete fusion reactions. The theoretically predicted excitation functions using PACE4 code were compared with the previously measured excitation functions. For non alpha emitting channels cross section values predicted by PACE4 in general were found to be in good agreement with the experimentally measured values. However, for alpha-emitting channels the measured cross-section values were found to be higher than the values predicted by PACE4. The observed disagreement may be credited to projectile break up in the vicinity of nn interaction. Keywords: alpha emitted, CF reaction, excitation functions, heavy ion fusion, incomplete fusion reaction, non alpha emitted
Comments:
14pages, 8 figures
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2204.05578 [pdf]
0 citations

Affiliations

first authorsco-authorsvia INSPIRE