Nuclear Theory·nucl-th

Tuesday·October 19, 2021

15 papers—6 primary·9 cross-listed

07
[Submitted on 15 Oct 2021] (cross-list from hep-ph)
Holographic modeling of nuclear matter and neutron stars
Matti Jarvinen🇰🇷
I review holographic models for (dense and cold) nuclear matter, neutron stars, and their mergers. I start by a brief general discussion on current knowledge of cold QCD matter and neutron stars, and go on discussing various approaches to model cold nuclear and quark matter by using gauge/gravity duality, pointing out their strengths and weaknesses. Then I focus on recent results for a complex bottom-up holographic framework (V-QCD), which also takes input from lattice QCD results, effective field theory, and perturbative QCD. Dense nuclear matter is modeled in V-QCD through a homogeneous non-Abelian bulk gauge field. Feasible "hybrid" equations of state for cold nuclear (and quark) matter can be constructed by using traditional methods (e.g., effective field theory) at low densities and the holographic V-QCD model at higher densities. I discuss the constraints from this approach to the properties of the nuclear to quark matter transition as well as to properties of neutron stars. Using such hybrid equations of state as an input for numerical simulations of neutron star mergers, I also derive predictions for the spectrum of produced gravitational waves.
Comments:
Review article published in Eur.Phys.J.C. 58 pages, 24 figures, 2 tables. v2: references and comments added
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2110.08281 [pdf]
EPJC(2022)·87 citations
08
[Submitted on 15 Oct 2021] (cross-list from nucl-ex)
Shapes, Softness and Non-Yrast Collectivity in 186W
V. S. Prasher🇺🇸 · A. J. Mitchell🇺🇸 · C. J. Lister🇺🇸 · P. Chowdhury🇺🇸 · L. Afanasieva🇺🇸 · M. Albers🇺🇸 · C. J. Chiara🇺🇸 · M. P. Carpenter🇺🇸 · D. Cline🇺🇸 · N. D'Olympia🇺🇸 · C. J. Guess🇺🇸 · A. B. Hayes🇺🇸 and 14 other authors
Non-yrast, excited states in neutron-rich $^{186}$ W were populated via inelastic-scattering reactions using beams of $^{136}$ Xe nuclei accelerated to 725 and 800 MeV. Levels populated in the reactions were investigated via particle- $γ$ coincidence techniques using the Gammasphere array of High-Purity Germanium detectors and the compact heavy-ion counter, CHICO2. The $K^{π} = 2^{+}$ ( $γ$ ), $K^{π} = 0^{+}$ and $K^{π} = 2^{-}$ (octupole) rotational side bands were extended to spins $14ℏ$ , $12ℏ$ , and $13ℏ$ , respectively. A staggering pattern observed in the energies of levels in the $K^{π} = 2^{+}$ band was found to be consistent with a potential that gets softer to vibration in the $γ$ degree of freedom with increasing spin. The odd-even staggering of states in the $K^{π} = 2^{-}$ band was found to exhibit a phase opposite to that seen in the $γ$ band; an effect most probably associated with Coriolis coupling to other, unobserved octupole vibrational bands in $^{186}$ W.
Comments:
14 pages, 16 figures
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2110.08347 [pdf]
PRC(2021)·1 citation
09
[Submitted on 15 Oct 2021] (cross-list from nucl-ex)
Measurement of the EMC effect in light and heavy nuclei
J. Arrington🇺🇸 · J. Bane🇺🇸 · A. Daniel🇺🇸 · N. Fomin🇺🇸 · D. Gaskell🇺🇸 · J. Seely🇺🇸 · R. Asaturyan🇦🇲 · F. Benmokhtar🇺🇸 · W. Boeglin🇺🇸 · P. Bosted🇺🇸 · M.H.S. Bukhari🇺🇸 · M.E. Christy🇺🇸 and 45 other authors
Inclusive electron scattering from nuclear targets has been measured to extract the nuclear dependence of the inelastic cross section in Hall C at the Thomas Jefferson National Accelerator facility. Results are presented for 2H, 3He, 4He, 9B, 12C, 63Cu and 197Au at an incident electron beam energy of 5.77 GeV for a range of momentum transfer from Q^2 = 2 to 7 (GeV/c)^2. These data improve the precision of the existing measurements of the EMC effect in the nuclear targets at large x, and allow for more detailed examinations of the A dependence of the EMC effect.
Comments:
28 pages, 23 figures, archival paper for Jefferson Lab experiment E03-103
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2110.08399 [pdf]
PRC(2021)·36 citations
10
[Submitted on 16 Oct 2021] (cross-list from nucl-ex)
Insight from the elliptic flow of identified hadrons measured in relativistic heavy-ion collisions
Prabhupada Dixit🇮🇳 · Md. Nasim🇮🇳
In this paper, we have discussed the transverse momentum dependence of elliptic flow measured in relativistic heavy-ion collisions. The transverse momentum dependence of the number of constituent quarks ( $n_{q}$ ) scaled $v_{2}$ is obtained for all the measured identified hadrons. The $n_{q}$ scaled $ϕ$ $v_{2}$ is found to be similar to $n_{q}$ scaled $Ω$ $v_{2}$ . This indicates that both $ϕ$ and $Ω$ are produced through quark recombination at RHIC energies. We also find $n_{q}$ scaled proton $v_{2}$ ( $v_{2}$ of light quarks) is higher than $n_{q}$ scaled $ϕ$ and $Ω$ $v_{2}$ ( $v_{2}$ of strange quarks) at $p_{T} / n_{q}$ $<$ 1.0 GeV/c. This can be explained by considering quark $v_{2}$ is proportional to its transverse kinetic energy considering mass of deconfined light and strange quarks equal to $\sim$ 4 MeV and $\sim$ 140 MeV, respectively.
Comments:
8 pages, 6 figures
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2110.08573 [pdf]
IJMPE(2022)·0 citations
11
[Submitted on 17 Oct 2021] (cross-list from hep-ph)
Nature of $X (2370)$
Xiang Sun🇨🇳 · Ling-Yun Dai🇨🇳 · Shi-Qing Kuang🇨🇳 · Wen Qin🇨🇳 · A.P. Szczepaniak🇺🇸
We address the nature of the $X (2370)$ resonance observed in the $J / ψ$ radiative decays, $J / ψ \to γ K^{+} K^{-} η^{'}$ , $J / ψ \to γ K_{S} K_{S} η^{'}$ and $J / ψ \to γ π^{+} π^{-} η^{'}$ . By studying the invariant mass spectra we confirm that decays of the $X (2370)$ into three pseudo-scalars are well described by an effective chiral Lagrangian. We extract the branching ratio of $J / ψ \to X (2370) γ$ and show that it is an order of magnitude larger compared to the glueball production rate predicted by lattice QCD. This indicates that $X (2370)$ is not likely to be a glueball candidate.
Comments:
5 pages, 2 figures, to be the same as the published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2110.08827 [pdf]
PRD(2022)·7 citations
12
[Submitted on 18 Oct 2021] (cross-list from nucl-ex)
The cross-section measurement for the $^{3} H (e, e^{'} K^{+}) nn Λ$ reaction
K. N. Suzuki · T. Gogami · B. Pandey · K. Itabashi · S. Nagao · K. Okuyama · S. N. Nakamura · L. Tang · D. Abrams · T. Akiyama · D. Androic · K. Aniol and 71 other authors
The small binding energy of the hypertrition leads to predictions of non-existence of bound hypernuclei for isotriplet three-body systems such as $nn Λ$ . However, invariant mass spectroscopy at GSI has reported events that may be interpreted as the bound $nn Λ$ state. The $nn Λ$ state was sought by missing-mass spectroscopy via the $(e, e^{'} K^{+})$ reaction at Jefferson Lab's experimental Hall A. The present experiment has higher sensitivity to the $nn Λ$ -state investigation in terms of better precision by a factor of about three. The analysis shown in this article focuses on the derivation of the reaction cross-section for the $^{3} H (γ^{*}, K^{+}) X$ reaction. Events that were detected in an acceptance, where a Monte Carlo simulation could reproduce the data well ( $∣ δ p / p ∣ < 4%$ ), were analyzed to minimize the systematic uncertainty. No significant structures were observed with the acceptance cuts, and the upper limits of the production cross-section of the $nn Λ$ state were obtained to be $21$ and $31 nb/sr$ at the $90%$ confidence level when theoretical predictions of $(- B_{Λ}, Γ) = (0.25, 0.8)$ and $(0.55, 4.7)$ MeV, respectively, were assumed. The cross-section result provides valuable information for examining the existence of $nn Λ$ .
Comments:
27 pages, 12 figures
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2110.09104 [pdf]
PTEP(2022)·13 citations
13
[Submitted on 18 Oct 2021] (cross-list from hep-ph)
Long-range neutrinoless double beta decay mechanisms
Jenni Kotila🇫🇮 · Jacopo Ferretti🇫🇮 · Francesco Iachello🇺🇸
Understanding the origin of lepton number violation is one of the fundamental questions in particle physics today. Neutrinoless double beta decay provides a way in which this violation can be tested. In this article, we derive the form of hadronic and leptonic matrix elements for all possible long-range mechanisms of neutrinoless double beta decay. With these, we calculate the numerical values of the nuclear matrix elements (NME) and phase space factors (PSF) by making use of the interacting boson model of the nucleus (IBM-2) for NMEs and of exact Dirac wave functions for the PSFs. We show that:\ (I) lepton number violation can occur even with zero (or very small) neutrino mass and (II) the angular correlations of the emitted electrons can distinguish between different models of non-standard (NS) mechanisms. We set limits on the coupling constants of some NS models, in particular Left-Right models and SUSY models.
Comments:
60 pages, 8 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2110.09141 [pdf]
16 citations
14
[Submitted on 18 Oct 2021] (cross-list from hep-ph)
Strangelets at finite temperature in an equivparticle model
H. M. Chen🇨🇳 · C. J. Xia🇨🇳 · G. X. Peng🇨🇳
The properties of strangelets at finite temperature are studied within the framework of an equivparticle model, where a new quark mass scaling and self-consistent thermodynamic treatment are adopted. The effects of finite volume and Coulomb energy are taken into account. Our results show that the temperature T, baryon number A and perturbation interactions have strong influences on the properties of strangelets. It is found that the energy per baryon M/A and charge-to-mass ratio fz decrease with baryon number A, while the mechanically stable radius R and strangeness per baryon fs are increasing. For a strangelet with a fixed baryon number, we note that as temperature T increases the quantites M/A, R, and fs are increasing while fz is decreasing. The effects of confinement and perturbative interactions are investigated as well by readjusting the corresponding parameters.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2110.09194 [pdf]
PRD(2022)·16 citations
15
[Submitted on 18 Oct 2021] (cross-list from hep-ph)
Accessing the pion 3D structure at US and China Electron-Ion Colliders
J. M. Morgado Chávez🇪🇸 · V. Bertone🇫🇷 · F. De Soto🇪🇸 · M. Defurne🇫🇷 · C. Mezrag🇫🇷 · H. Moutarde🇫🇷 · J. Rodríguez-Quintero🇪🇸 · J. Segovia🇪🇸
We present in this letter the first systematic feasibility study of accessing generalised parton distributions of the pion at an electron-ion collider through deeply virtual Compton scattering at next-to-leading order. It relies on a state-of-the-art model, able to fulfil by construction all the theoretical constraints imposed on generalised parton distributions. Strikingly, our analysis shows that quarks and gluons interfere destructively and that gluon dominance could be spotted by a sign change of the DVCS beam spin asymmetry.
Comments:
7 pages, 4 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2110.09462 [pdf]
PRL(2022)·55 citations

Affiliations

first authorsco-authorsvia INSPIRE