Nuclear Theory·nucl-th

Friday·November 4, 2022

13 papers—3 primary·10 cross-listed

04
[Submitted on 2 Nov 2022] (cross-list from hep-ph)
The persistent nonperturbative charm enigma
Marco Guzzi🇺🇸 · T. J. Hobbs🇺🇸 · Keping Xie🇺🇸 · Joey Huston🇺🇸 · Pavel Nadolsky🇺🇸 · C.-P. Yuan🇺🇸
The question of the existence and possible magnitude of nonperturbative (often called "intrinsic") charm in the proton has long confounded attempts to cleanly isolate such a contribution in global analyses of high-energy experiments. In this letter, we show that the available (non)perturbative QCD theory and hadronic data have still not developed to a sufficient level to clearly resolve this problem. We highlight a number of challenging aspects that must be confronted in extracting nonperturbative charm in PDF fits, and in so doing, present an updated next-to-next-to-leading order CT analysis of fitted charm, CT18 FC, which we also compare to recent studies. We outline the theory developments and future data needed to make progress on this subject.
Comments:
10 pages, 2 figures in main Letter; includes 6 pages of Supplementary Discussion with 6 additional figures; updated following publication in PLB 843 (2023) 137975
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2211.01387 [pdf]
PLB(2023)·68 citations
05
[Submitted on 2 Nov 2022] (cross-list from astro-ph.HE)
Connecting small-scale to large-scale structures of fast neutrino-flavor conversion
Hiroki Nagakura🇯🇵 · Masamichi Zaizen🇯🇵
We present a systematic study of fast neutrino-flavor conversion (FFC) with both small-scale and large-scale numerical simulations in spherical symmetry. We find that FFCs can, in general, reach a quasi-steady state, and these features in the non-linear phase are not characterized by the growth rate of FFC instability but rather angular structures of electron neutrino lepton number (ELN) and heavy one (XLN). Our result suggests that neutrinos can almost reach a flavor equipartition even in cases with low growth rate of instability (e.g., shallow ELN crossing) and narrow angular regions (in momentum space) where flavor conversions occur vigorously. This exhibits that ELN and XLN angular distributions can not provide a sufficient information to determine total amount of flavor conversion in neutrinos and antineutrinos of all flavors. Based on the results of our numerical simulations, we provide a new approximate scheme of FFC that is designed so that one can easily incorporate effects of FFCs in existing classical neutrino transport codes for the study of core-collapse supernova (CCSN) and binary neutron star merger (BNSM). The scheme has an ability to capture key features of quasi-steady state of FFCs without solving quantum kinetic neutrino transport, which will serve to facilitate access to FFCs for CCSN and BNSM theorists.
Comments:
Accepted to PRD
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2211.01398 [pdf]
PRD(2023)·38 citations
06
[Submitted on 3 Nov 2022] (cross-list from hep-ph)
Charmed-strange tetraquarks and their decays in a potential quark model
Feng-Xiao Liu🇨🇳 · Ru-Hui Ni🇨🇳 · Xian-Hui Zhong🇨🇳 · Qiang Zhao🇨🇳
In the framework of a nonrelativistic potential quark model, we investigate the mass spectrum of the $1 S$ -wave charmed-strange tetraquark states of $c n s ˉ n ˉ$ and $cs n ˉ n ˉ$ ( $n = u$ or $d$ ) systems. The tetraquark system is solved by a correlated Gaussian method. With the same parameters fixed by the meson spectra, we obtained the mass spectra for the $1 S$ -wave tetraquark states. Furthermore, based on the predicted tetraquark spectra we estimate their rearrangement decays in a quark-exchange model. We find that the rearrangement decays of the tetraquarks may be mainly driven by the spin-spin interactions. The resonances $X_{0} (2900)^{0}$ and $T_{c s ˉ 0}^{a} (2900)^{++ /0}$ reported from LHCb may be assigned to be the lowest $1 S$ -wave tetraquark states $T ˉ_{cs 0}^{f} (2818)$ and $T_{c s ˉ 0}^{a} (2828)$ classified in the quark model, respectively. It also allows us to extract the couplings for the initial tetraquark states to their nearby $S$ -wave interaction channels. We find that some of these couplings turn out to be sizeable. Following the picture of the wavefunction renormalization for the near-threshold strong $S$ -wave interactions, the sizeable coupling strengths can be regarded as an indication of their dynamic origins as candidates for hadronic molecules. Furthermore, our predictions suggest that signals for the $1 S$ -wave charmed-strange tetraquark states can also be searched in the other channels, such as $D^{0} K^{+}$ , $D^{+} K^{+}$ , $D^{*+} K^{-}$ , $D^{*+} K^{+}$ , $D^{* 0} K^{+}$ , $D^{0} K ˉ^{* 0}$ , $D_{s}^{+} ρ^{0}$ , etc.
Comments:
9 pages, 1 figure, the mistakes of the predicted decay properties have been corrected
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2211.01711 [pdf]
PRD(2023)·47 citations
07
[Submitted on 3 Nov 2022] (cross-list from hep-ph)
Probing the hadron mass spectrum in dense two-color QCD with the linear sigma model
Daiki Suenaga🇯🇵 · Kotaro Murakami🇯🇵 · Etsuko Itou🇯🇵 · Kei Iida🇯🇵
We investigate modifications of hadron masses at finite quark chemical potential in two-flavor and two-color QCD, of which the data are available from lattice simulations, within a linear sigma model based on approximate Pauli-Gursey $S U (4)$ symmetry. The model describes not only ground-state scalar diquarks and pseudo-scalar mesons but also the excited pseudo-scalar diquarks and scalar mesons; each ground-state diquark (meson) has the corresponding excited diquark (hadron) with opposite parity as a chiral partner. Effects of chiral symmetry breaking and diquark condensates are incorporated by a mean-field treatment. We show that various mixings among the hadrons, which are triggered by the breakdown of baryon number conservation in the superfluid phase, lead to a rich hadron mass spectrum. We discuss the influence of $U (1)_{A}$ anomaly on the density dependence of the mass spectrum and also manifestations of the chiral partner structures as density increases in the superfluid phase. The predicted hadron masses are expected to provide future lattice simulations with useful information on such symmetry properties in dense two-color QCD.
Comments:
16 pages, 6 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2211.01789 [pdf]
PRD(2023)·22 citations
08
[Submitted on 3 Nov 2022] (cross-list from nucl-ex)
Mirror beta transitions
K. Riisager
Beta decays of mirror nuclei differ in Q-value, but will otherwise proceed with transitions of similar strength. The current status is reviewed: Fermi transitions are all very similar, whereas Gamow-Teller transitions can differ in strength by more than a factor two. The main cause of the asymmetries appears to be binding energy differences between the mirror systems.
Comments:
14 pages, 5 figures, submitted to Eur. Physics. J. A
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2211.01864 [pdf]
EPJA(2023)·3 citations
09
[Submitted on 3 Nov 2022] (cross-list from nucl-ex)
$^{178}$ Hg and asymmetric fission of neutron-deficient pre-actinides
A. Jhingan🇮🇳 · C. Schmitt🇫🇷 · A. Lemasson🇫🇷 · S. Biswas🇫🇷 · Y.H. Kim🇰🇷 · D. Ramos🇫🇷 · A.N. Andreyev🇬🇧 · D. Curien🇫🇷 · M. Ciemala🇵🇱 · E. Clément🇫🇷 · O. Dorvaux🇫🇷 · B. De Canditiis🇫🇷 and 18 other authors
Fission at low excitation energy is an ideal playground to probe the impact of nuclear structure on nuclear dynamics. While the importance of structural effects in the nascent fragments is well-established in the (trans-)actinide region, the observation of asymmetric fission in several neutron-deficient pre-actinides can be explained by various mechanisms. To deepen our insight into that puzzle, an innovative approach based on inverse kinematics and an enhanced version of the VAMOS++ heavy-ion spectrometer was implemented at the GANIL facility, Caen. Fission of $^{178}$ Hg was induced by fusion of $^{124}$ Xe and $^{54}$ Fe. The two fragments were detected in coincidence using VAMOS++ supplemented with a new SEcond Detection arm. For the first time in the pre-actinide region, access to the pre-neutron mass and total kinetic energy distributions, and the simultaneous isotopic identification of one the fission fragment, was achieved. The present work describes the experimental approach, and discusses the pre-neutron observables in the context of an extended asymmetric-fission island located south-west of $^{208}Pb. A comparison with different models is performed, demonstrating the importance of this "new" asymmetric-fission island for elaborating on driving effects in fission.
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2211.01879 [pdf]
PRC(2022)·11 citations
10
[Submitted on 3 Nov 2022] (cross-list from hep-ph)
$X (3872)$ , $X (4014)$ , and their bottom partners at finite temperature
Gloria Montaña🇪🇸 · Angels Ramos🇪🇸 · Laura Tolos🇪🇸 · Juan M. Torres-Rincon🇪🇸
The properties of the $X (3872)$ and its spin partner, the $X (4014)$ , are studied both in vacuum and at finite temperature. Using an effective hadron theory based on the hidden-gauge Lagrangian, the $X (3872)$ is dynamically generated from the $s$ -wave rescattering of a pair of pseudoscalar and vector charm mesons. By incorporating the thermal spectral functions of open charm mesons, the calculation is extended to finite temperature. Similarly, the properties of the $X (4014)$ are obtained out of the scattering of charm vector mesons. By applying heavy-quark flavor symmetry, the properties of their bottom counterparts in the axial-vector and tensor channels are also predicted. All the dynamically generated states show a decreasing mass and acquire an increasing decay width with temperature, following the trend observed in their meson constituents. These results are relevant in relativistic heavy-ion collisions at high energies, in analyses of the collective medium formed after hadronization or in femtoscopic studies, and can be tested in lattice-QCD calculations exploring the melting of heavy mesons at finite temperature.
Comments:
32 pages, 7 figures, 3 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2211.01896 [pdf]
PRD(2023)·23 citations
11
[Submitted on 3 Nov 2022] (cross-list from astro-ph.IM)
Modeling Solids in Nuclear Astrophysics with Smoothed Particle Hydrodynamics
Irina Sagert · Oleg Korobkin · Ingo Tews · Bing-Jyun Tsao · Hyun Lim · Michael J. Falato · Julien Loiseau
Smoothed Particle Hydrodynamics (SPH) is a frequently applied tool in computational astrophysics to solve the fluid dynamics equations governing the systems under study. For some problems, for example when involving asteroids and asteroid impacts, the additional inclusion of material strength is necessary in order to accurately describe the dynamics. In compact stars, that is white dwarfs and neutron stars, solid components are also present. Neutron stars have a solid crust which is the strongest material known in nature. However, their dynamical evolution, when modeled via SPH or other computational fluid dynamics codes, is usually described as a purely fluid dynamics problem. Here, we present the first 3D simulations of neutron-star crustal toroidal oscillations including material strength with the Los Alamos National Laboratory SPH code FleCSPH. In the first half of the paper, we present the numerical implementation of solid material modeling together with standard tests. The second half is on the simulation of crustal oscillations in the fundamental toroidal mode. Here, we dedicate a large fraction of the paper to approaches which can suppress numerical noise in the solid. If not minimized, the latter can dominate the crustal motion in the simulations.
Comments:
28 pages, 34 figures
Subjects:
Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Theory (nucl-th)
arXiv:
2211.01927 [pdf]
Astrophys.J.Suppl.(2023)·3 citations
12
[Submitted on 3 Nov 2022] (cross-list from hep-ph)
Detecting nuclear mass distribution in isobar collisions via charmonium
Jiaxing Zhao🇫🇷 · Shuzhe Shi🇺🇸
The collective properties of final state hadrons produced in the high statistics $_{44}^{96}$ Ru+ $_{44}^{96}$ Ru and $_{40}^{96}$ Zr+ $_{40}^{96}$ Zr collisions at $s_{NN} = 200 GeV$ are found to be significantly different. Such differences were argued to be precise probes of the difference in nucleon distribution in the isobar nuclei. We investigate the $J / ψ$ production in the isobar collision via a relativistic transport approach. By comparing the isobar systems according to equal centrality bin and equal multiplicity bin, we find that the yield ratio of $J / ψ$ is sensitive to the differences in both the number of binary collisions and the medium evolution. Besides, the elliptic flow $v_{2}$ of $J / ψ$ is qualitatively different from the light hadrons, and the ratio between Ru+Ru and Zr+Zr collisions is sensitive to the medium evolution. The charmonium production provides an independent probe to study the nucleon distribution in the isobar system.
Comments:
8 pages, 4 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2211.01971 [pdf]
EPJC(2023)·8 citations
13
[Submitted on 3 Nov 2022] (cross-list from astro-ph.HE)
A Bayesian inference of relativistic mean-field model for neutron star matter from observation of NICER and GW170817/AT2017gfo
Zhenyu Zhu · Ang Li · Tong Liu
The observations of optical and near-infrared counterparts of binary neutron star mergers not only enrich our knowledge about the abundance of heavy elements in the Universe, or help reveal the remnant object just after the merger as generally known, but also can effectively constrain dense nuclear matter properties and the equation of state (EOS) in the interior of the merging stars. Following the relativistic mean-field description of nuclear matter, we perform the Bayesian inference of the EOS and the nuclear matter properties using the first multi-messenger event GW170817/AT2017gfo, together with the NICER mass-radius measurements of pulsars. The kilonova is described by a radiation-transfer model with the dynamical ejecta, and light curves connect with the EOS through the quasi-universal relations between the ejecta properties (the ejected mass, velocity, opacity or electron fraction) and binary parameters (the mass ratio and reduced tidal deformability). It is found that the posterior distributions of the reduced tidal deformability from the AT2017gfo analysis display a bimodal structure, with the first peak enhanced by the GW170817 data, leading to slightly softened posterior EOSs, while the second peak cannot be achieved by a nuclear EOS with saturation properties in their empirical ranges. The inclusion of NICER data in our analyses results in stiffened EOS posterior because of the massive pulsar PSR J0740+6620. We give results at nuclear saturation density for the nuclear incompressibility, the symmetry energy and its slope, as well as the nucleon effective mass, from our analysis of those observational data.
Comments:
Added discussions of PREX-II and GW190814, accepted by APJ
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Theory (nucl-th)
arXiv:
2211.02007 [pdf]
ApJ(2023)·49 citations

Affiliations

first authorsco-authorsvia INSPIRE