Nuclear Theory·nucl-th

Wednesday·February 19, 2025

6 papers—4 primary·2 cross-listed

01
[Submitted on 15 Feb 2025]
Chiral Symmetry in Dense Matter with Meson Condensation
Takumi Muto🇯🇵 · Toshiki Maruyama🇯🇵 · Toshitaka Tatsumi🇯🇵
Kaon condensation in hyperon-mixed matter [( $Y$ + $K$ ) phase], which may be realized in neutron stars, is discussed on the basis of chiral symmetry. With the use of the effective chiral Lagrangian for kaon--baryon and kaon--kaon interactions; coupled with the relativistic mean field theory and universal three-baryon repulsive interaction, we clarify the effects of the $s$ -wave kaon--baryon scalar interaction simulated by the kaon--baryon sigma terms and vector interaction (Tomozawa--Weinberg term) on kaon properties in hyperon-mixed matter, the onset density of kaon condensation, and the equation of state with the ( $Y$ + $K$ ) phase. In particular, the quark condensates in the ( $Y$ + $K$ ) phase are obtained, and their relevance to chiral symmetry restoration is discussed.
Comments:
22 pages, 7 figures, published in Symmetry 2025,17,270, the Special Issue: Chiral Symmetry, and Restoration in Nuclear Dense Matter. arXiv admin note: substantial text overlap with arXiv:2411.09967
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2502.12192 [pdf]
Symmetry(2025)·3 citations
02
[Submitted on 18 Feb 2025]
Analytic continuation in coupling constant applied to two-proton emitters
Tomohiro Oishi · Masaaki Kimura
For quantum meta-stable problems with three particles, the $^{6}$ Be and $^{16}$ Ne nuclei as two-proton ( $2 p$ ) emitters provide a testing field. Considering the complexity of many-body meta-stable systems, a tractable solver has been on demand. We apply the analytic continuation in coupling constant (ACCC) to these nuclei, and confirm that this method can solve such problems consistently to the time-dependent results as well as to the experimental data. The sensitivity of the $2 p$ energies and widths to the proton-proton interaction is also investigated. The $^{6}$ Be shows a smooth shift from short-life to long-life systems according to the proton-proton interaction. Same is concluded for the $2^{+}$ resonance of $^{16}$ Ne. In contrast, for the first and second $0^{+}$ resonances of $^{16}$ Ne, their energies and widths show the avoid-crossing behaviour, due to the coupling of two configurations in the core-proton subsystem, $^{15}$ F. Since it requires only the bound-state solvers, the ACCC can be a low-cost option to solve three or more-body resonances.
Comments:
6 pages, 6 figures, 2 tables
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2502.12577 [pdf]
PRC(2025)·1 citation
03
[Submitted on 18 Feb 2025]
AC nuclear Stark effect in H-atom via super-intense laser-atom interaction
Ali Raza Mirza · Rizwan Abbas · Atif Shahbaz
We investigate the nuclear Stark effect induced in hydrogen-like atomic nuclei under super-intense laser fields. Since laser wavelengths are generally larger than nuclear dimensions, direct laser-nucleus interaction is unfeasible. Instead, this effect is induced indirectly through electron oscillations in the laser field, which produce a periodic electric field that shifts the nuclear energy levels. Using perturbation theory, we derive an expression for the energy shift and dynamic polarizability of the nucleus as a function of laser parameters. Our findings reveal that the Nuclear Stark effect can be controlled by adjusting the laser frequency and intensity, potentially enabling applications in nuclear and quantum optical systems.
Comments:
4 Pages, 3 Figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2502.12683 [pdf]
0 citations
04
[Submitted on 18 Feb 2025]
Initial-state-driven spin correlations in high-energy nuclear collisions
Giuliano Giacalone🇨🇭 · Enrico Speranza🇨🇭
In the study of spin-polarization phenomena in heavy-ion collisions, it is typically assumed that final-state particles are polarized through thermal vorticity and shear. In this sense, polarization is a final-state effect. Here, we propose a different mechanism. We postulate that the collision of spin-carrying nucleons generates an initial transverse spin density, inducing a net polarization of the QCD fireball along a random direction. If the net spin is conserved throughout the evolution of the fireball, the final-state particles should exhibit measurable polarization. Within a wounded nucleon picture, we estimate that initial-state fluctuations induce a net polarization of $Λ$ baryons which is around $1%$ in central collisions and over $10%$ in noncentral collisions, significantly exceeding the contributions from thermal vorticity and shear. We introduce a two-particle angular correlation observable designed to reveal initial net-spin fluctuations, and emphasize the main signatures to look for in experiments. We argue that the discovery of these phenomena would have profound implications for nuclear structure and our understanding of spin in relativistic hydrodynamics.
Comments:
10 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2502.13102 [pdf]
12 citations
05
[Submitted on 17 Feb 2025] (cross-list from hep-ph)
A Precise Determination of $α_{s}$ from the Heavy Jet Mass Distribution
Miguel A. Benitez🇪🇸 · Arindam Bhattacharya🇺🇸 · Andre H. Hoang🇦🇹 · Vicent Mateu🇪🇸 · Matthew D. Schwartz🇺🇸 · Iain W. Stewart🇦🇹 · Xiaoyuan Zhang🇺🇸
A global fit for $α_{s} (m_{Z})$ is performed on available $e^{+} e^{-}$ data for the heavy jet mass distribution. The state-of-the-art theory prediction includes $O (α_{s}^{3})$ fixed-order results, N $^{3}$ LL $^{'}$ dijet resummation, N $^{2}$ LL Sudakov shoulder resummation, and a first-principles treatment of power corrections in the dijet region. Theoretical correlations are incorporated through a flat random-scan covariance matrix. The global fit results in $0.114 8_{- 0.0022}^{+ 0.0015}$ , compatible with similar determinations from thrust and $C$ -parameter. Dijet resummation is essential for a robust fit, as it engenders insensitivity to the fit-range lower cutoff; without resummation the fit-range sensitivity is overwhelming. In addition, we find evidence for a negative power correction in the trijet region if and only if Sudakov shoulder resummation is included.
Comments:
4 pages + supplemental material, 8 figures, 3 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2502.12253 [pdf]
29 citations
06
[Submitted on 18 Feb 2025] (cross-list from nucl-ex)
Extreme Shape Coexistence Observed in $^{70}$ Co
Cade Dembski · Artemis Spyrou · B. Alex Brown · Sean N. Liddick · Hannah C. Berg · Darren L. Bleuel · Katherine Childers · Benjamin P. Crider · Alexander C. Dombos · Erin C. Good · Caley Harris · Ann-Cecilie Larsen and 13 other authors
The shape of the atomic nucleus is a property which underpins our understanding of nuclear systems, impacts the limits of nuclear existence, and enables probes of physics beyond the Standard Model. Nuclei can adopt a variety of shapes, including spheres, axially deformed spheroids, and pear shapes. In some regions of the nuclear chart where a spherical nucleus would naively be expected, deformed nuclear states can result from collective action of constituent protons and neutrons. In a small subset of nuclei both spherical and deformed nuclear states have been experimentally observed, a phenomenon termed shape coexistence. We present spectroscopic evidence for the coexistence of $J^{π} = 1 +$ spherical and deformed states in $^{70}$ Co, separated by less than 275~keV. This close degeneracy of levels with the same $J^{π}$ and different shapes demonstrates an extreme example of shape coexistence resulting from the interplay of independent particle motion and collective behavior in highly unstable nuclear systems and identifies the Co isotopes as a transition point between deformed ground states observed in the Cr isotopes and spherical configurations observed in the closed-shell Ni isotopes.
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2502.12681 [pdf]
Commun.Phys.(2025)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE

Chiral Symmetry in Dense Matter with Meson Condensation

Analytic continuation in coupling constant applied to two-proton emitters

AC nuclear Stark effect in H-atom via super-intense laser-atom interaction

Initial-state-driven spin correlations in high-energy nuclear collisions

A Precise Determination of αs​ from the Heavy Jet Mass Distribution

Extreme Shape Coexistence Observed in 70Co

Affiliations

A Precise Determination of $α_{s}$ from the Heavy Jet Mass Distribution

Extreme Shape Coexistence Observed in $^{70}$ Co